In situ regenerative electrodes for Z-pinch plasma confinement systems.

Abstract

Methods and systems are provided for Z-pinch and other plasma confinement utilizing various electrode compositions and configurations. In one embodiment, a plasma confinement system includes a plurality of electrodes, each electrode of the plurality of electrodes disposed coaxially with respect to an assembly region of the plasma confinement system and positioned to be exposed to the assembly region, and one or more electrodes of the plurality of electrodes include an electrode material that evolves hydrogen gas above a threshold temperature. In additional or alternative embodiments, the plasma confinement system includes a nose cone and an electrode body including a liquid metal, where a portion of the liquid metal forms a protective film between a surface of the nose cone and an exterior of the nose cone during operation of the plasma confinement system.

Description

[Technical field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority to each of U.S. Provisional Patent Application No. 63 / 303,473, entitled "ELECTRODE AND DECOMPOSABLE ELECTRODE MATERIAL FOR Z-PINCH PLASMA CONFINEMENT SYSTEM," filed January 26, 2022, and U.S. Provisional Patent Application No. 63 / 303,477, entitled "IN SITU RENEWABLE ELECTRODE FOR Z-PINCH PLASMA CONFINEMENT SYSTEM," filed January 26, 2022. The entire contents of each of the above-mentioned applications are incorporated herein by reference for all purposes.

[0002] STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT This invention was made, at least in part, with Government support under Grant Nos. DE-AR001010 and DE-AR001260 awarded by the U.S. Department of Energy. The Government has certain rights in this invention.

[0003] FIELD OF THE DISCLOSURE Embodiments of the subject matter disclosed herein relate to methods and systems for plasma confinement to induce thermonuclear fusion reactions, and more particularly, to electrode compositions and configurations for Z-pinch plasma confinement systems. [Background technology]

[0004] Economical, efficient, and self-sustainable fusion energy has proven elusive. Even with continued advances, the amount of power input to a fusion reactor has almost invariably exceeded the power output by the fusion reactor, especially in production-scale designs. Several factors influence the occurrence of self-sustaining, captureable fusion energy, or "fusion ignition." For example, the configuration of a fusion reactor may be discussed in terms of the quality of plasma confinement within the fusion reactor, which may be quantified by the triple product of plasma density, plasma confinement time, and plasma temperature. Maximizing one or more factors of the triple product to obtain net fusion energy output is particularly challenging.

[0005] One example of a reaction that can be utilized is the fusion of deuterium and tritium nuclei, which is given by the following equation: 2 H+ 3 H → 4 He+n (1) One complicating aspect introduced by the deuterium-tritium fusion reaction is the introduction of free neutron by-products n. In combination with the discharge current (which results in a high-energy ion flux during the operation of the fusion reactor), the free neutrons can erode material from the surface of the electrodes interfacing with the plasma confinement chamber. A reduction in the discharge current or repetition rate of the discharge current may correspondingly reduce the erosion of the electrodes, but the net power generation may also be affected, such that fusion ignition may remain unattained. [Brief description of the drawings]

[0006] Various embodiments and techniques are described with reference to the drawings.

[0007] [Figure 1] 1 shows a schematic cross-sectional view of a plasma confinement system including multiple electrodes according to at least one embodiment. [Diagram 2]FIG. 1 illustrates a block diagram of a method for operating a plasma confinement system for stabilization of a Z-pinch discharge, for example by initiating and driving a shear ion velocity flow therein, according to at least one embodiment. [Figure 3A] 2A-2C show schematic cross-sectional views of a process for initiating and driving shear ion velocity flow in the plasma confinement system of FIG. 1 for stabilization of a Z-pinch discharge according to at least one embodiment. [Figure 3B] 2A-2C show schematic cross-sectional views of a process for initiating and driving shear ion velocity flow in the plasma confinement system of FIG. 1 for stabilization of a Z-pinch discharge according to at least one embodiment. [Figure 3C] 2A-2C show schematic cross-sectional views of a process for initiating and driving shear ion velocity flow in the plasma confinement system of FIG. 1 for stabilization of a Z-pinch discharge according to at least one embodiment. [Figure 3D] 2A-2C show schematic cross-sectional views of a process for initiating and driving shear ion velocity flow in the plasma confinement system of FIG. 1 for stabilization of a Z-pinch discharge according to at least one embodiment. [Figure 3E] 2A-2C show schematic cross-sectional views of a process for initiating and driving shear ion velocity flow in the plasma confinement system of FIG. 1 for stabilization of a Z-pinch discharge according to at least one embodiment. [Figure 3F] 2A-2C show schematic cross-sectional views of a process for initiating and driving shear ion velocity flow in the plasma confinement system of FIG. 1 for stabilization of a Z-pinch discharge according to at least one embodiment. [Figure 4] 1 shows a schematic cross-sectional view of a plasma confinement system including multiple electrodes according to at least one embodiment. [Diagram 5] 1 illustrates a block diagram of a method of forming an electrode and operating a plasma confinement system therewith, according to at least one embodiment. [Figure 6] 1 shows a plot of multiple ion implantation depths in titanium as a function of ion energy, eg, ions. [Figure 7]1 shows plots of multiple isothermal pressures as a function of H:Ti atomic ratio for examples of titanium hydride. [Figure 8A] FIG. 1 illustrates a schematic cross-sectional view of electrodes in a plasma confinement chamber of a thermonuclear fusion reactor during its operation, according to at least one embodiment. [Figure 8B] 8B illustrates a schematic cross-section of the electrode of FIG. 8A before and after operation of a thermonuclear fusion reactor, according to at least one embodiment. [Figure 9A] 1 illustrates a block diagram of a method for operating a plasma confinement system including an in-situ regenerable electrode, according to at least one embodiment. [Figure 9B] 1 illustrates a block diagram of a method for operating a plasma confinement system including an in-situ regenerable electrode, according to at least one embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] The technology described and suggested herein includes a plasma confinement system including a plurality of electrodes, each electrode of the plurality of electrodes disposed coaxially relative to an assembly region of the plasma confinement system and positioned to be exposed to the assembly region, and one or more electrodes of the plurality of electrodes including an electrode material that releases hydrogen gas above a threshold temperature.

[0009] In some embodiments, the thermonuclear fusion reactor includes a plasma confinement chamber, an inner electrode, and an outer electrode at least partially surrounding the inner electrode, where one or both of the inner electrode or the outer electrode includes a metal hydride that releases a fuel gas between the inner electrode and the outer electrode to contribute a plasma to a thermonuclear fusion process of the thermonuclear fusion reactor. For example, one or both of the inner electrode or the outer electrode may include a section composed of a metal hydride.

[0010] In some embodiments, the method includes generating a thermonuclear fusion reaction in a thermonuclear fusion reactor by at least heating an electrode formed from a bulk material and a metal layer evaporated thereon, the metal layer being loaded with deuterium and / or tritium and causing the electrode to release hydrogen gas, forming a plasma inside the thermonuclear fusion reactor using the hydrogen gas, and compressing the plasma through the electrode using an electric current directed at the plasma to generate a thermonuclear fusion reaction. For example, the metal layer may be comprised of a metal hydride (e.g., a metal deuteride or a metal tritide, or a combination thereof). The metal hydride may be formed after evaporation of the metal layer on the bulk material and loading of the metal layer with deuterium and / or tritium.

[0011] In at least one embodiment, a plasma confinement system includes a plasma confinement chamber, an electrode body, the electrode body including a nosecone positioned to be exposed to the plasma confinement chamber, an internal reservoir fluidly connected to a liquid metal source, the liquid metal source storing at least a portion of the liquid metal and / or supplying liquid metal to the internal reservoir during operation of the plasma confinement system, and a plurality of internal liquid flow channels extending into a surface of the nosecone to fluidly connect the internal reservoir to the plasma confinement chamber.

[0012] A thermonuclear fusion reactor according to various embodiments includes a plasma confinement chamber and an electrode at least partially enclosed within the plasma confinement chamber, the electrode including a nose cone that intersects an axis of a plasma arc confined within the plasma confinement chamber during operation of the thermonuclear fusion reactor, and a liquid metal meniscus formed on a surface of the nose cone, the liquid metal meniscus directly interacting with the confined plasma arc during operation of the thermonuclear fusion reactor.

[0013] A method according to various embodiments includes flowing liquid metal from an internal reservoir of the electrode onto an exterior surface of the electrode at a liquid metal flow rate, generating a confined plasma arc to ablate the liquid metal from the exterior surface at a liquid metal ablation rate, and adjusting the liquid metal flow rate by adjusting one or more of a liquid metal level in the internal reservoir, an inert gas pressure within the internal reservoir, or a liquid metal temperature in response to the liquid metal flow rate deviating from the liquid metal ablation rate by more than a threshold magnitude.

[0014] These and other aspects, advantages, and alternatives will become apparent to those skilled in the art from a reading of the following detailed description, taken with, where appropriate, reference to the accompanying drawings. Moreover, it should be understood that the description and figures provided herein are intended to illustrate the invention by way of example only, and as such, numerous variations are possible.

[0015] For example, the following description relates to various embodiments of systems and methods for confining plasma in a fusion reactor to a sufficient temperature and sufficient density to induce thermonuclear fusion. In some embodiments, the power from thermonuclear fusion may be utilized for energy generation / storage. However, other use cases are envisioned for the disclosed embodiments or variations thereof, such as propulsion (e.g., space vehicles, aircraft, seaplanes, and submarines, etc.), research, etc. In extreme environments (e.g., reduced gravity environments on board space vehicles), certain modifications may be made, for example, to maintain performance. For example, the liquid metal meniscus may be held to the surface of the nosecone via surface tension and / or capillary action, but additional components may be implemented to prevent the ablated metal from interfering with the confined plasma arc. As an example, a mechanical plunger may be included that may induce a flow of liquid metal from an internal reservoir to the surface of the nosecone, as well as in the reverse direction (from the surface of the nosecone to the internal reservoir, in a similar operating principle to a hypodermic syringe). However, in certain embodiments, holding tighter tolerances on the mechanical plunger may be complicated by expansion from higher temperatures and neutron flux.

[0016] In an exemplary embodiment, plasma confinement may be achieved via a Z-pinch configuration, where an electric current (also known as a "Z-pinch discharge current" or "pinch current") is discharged through the plasma to generate a magnetic field that compresses or "pinches" the plasma along an axis (e.g., along a linear path through the assembly region of the plasma confinement chamber). The electric current is discharged between a pair of electrodes, which may be subject to significant rates of ion, electron, and / or neutron bombardment during operation of the fusion reactor. As a result, one or more electrodes in the plasma confinement chamber may degrade or erode (e.g., lose mass) over the life of the fusion reactor.

[0017] At production scale, the repetition rate of the discharge in the plasma confinement chamber may be on the order of tens of Hertz. In one example, based on known spark gap erosion rates (which may approximate erosion in a Z-pinch configuration), a discharge current sufficient to induce desirable plasma confinement at a repetition rate of 10-11 Hz may result in hundreds of grams of carbon electrode erosion per hour. Such severe electrode erosion may be sufficient to limit the lifetime of a continuously operating fusion reactor to less than one month.

[0018] In particular, but without limitation, of interest is maintaining a stable (e.g., little or no discernible degradation) interface between the electrode and the confined plasma arc in the plasma confinement chamber and / or improving overall fusion reactor performance. At least two strategies are envisioned herein, which may be implemented in isolation in some embodiments and in combination in other embodiments: (i) forming a static solid electrode from an electrode material that aids or improves fusion reactor performance (e.g., compared to carbon), and (ii) forming an in-situ regenerable electrode to prevent degradation within the bulk of the electrode.

[0019] For the formation of static solid electrodes, performance improvements from electrode materials selected solely for resistance to degradation may be limited by orders of magnitude. Thus, electrode materials that provide additional benefits or otherwise improve conditions in plasma confinement chambers for thermonuclear fusion may be desirable. In an exemplary embodiment, the electrode, or at least a portion thereof, may be formed from one or more metal hydrides. A given metal hydride may be considered as a two-phase system in reversible equilibrium according to the following equation:

number

[0020] Furthermore, M.H. n is deuterium ( 2 H or D) and / or tritium ( 3 H or T) (e.g., via reaction of M with D2 and / or T2), electrodes formed from metal deuterides and / or metal tritides (e.g., MD l T m , where l+m=n) can directly participate in thermonuclear fusion reactions (e.g., reaction (1)) in the plasma confinement chamber upon ion bombardment of the electrodes. Thus, MH n may provide an additional source of fusion neutrons (e.g., as a by-product of deuterium-tritium fusion).

[0021] In certain embodiments, MH n can itself consume free neutrons to provide an internal source of tritium. For example, lithium deuteride ( 6LiD) can be used as a tritium source ("tritium breeding") as follows: 6 Li 2 H+n→ 4 He+ 3 H+ 2 H (3) In some embodiments, tritium sourced via reaction (3) may provide an internal supplement to an external tritium source (e.g., a tritium bleeding blanket, such as a lithium-containing ceramic, or a circulating liquid metal wall, such as lead-lithium; such configurations may also function as electrodes in place of, for example, the outer electrode 304 of FIG. 1).

[0022] Thus, one technical effect of using one or more metal hydrides (e.g., metal deuterides and / or metal tritides) as the electrode material is that the electrode itself may interact with the confined plasma arc to complement or augment thermonuclear fusion within the plasma confinement chamber of the fusion reactor.

[0023] In addition to or in lieu of adjusting the static solid bulk or composite composition or formulation of the electrode, the electrode and the assembly region may be continuously renewed at an interface (e.g., without any intervening components or volumes) where they are directly coupled to each other to form an in situ regenerable electrode (as used herein, "interface" or "by an interface" may refer to a solid-gas or liquid-gas phase boundary where a solid or liquid phase is in direct contact with a gas phase). As an example, the interface may include a solid that is continuously supplied (e.g., supplied without interruption or with no appreciable delay during fusion reactor operation) or dynamically supplied (e.g., responsively supplied to maintain a predetermined thickness at the interface) to the surface of the electrode. As another example, the interface may include a liquid meniscus that is continuously supplied or dynamically supplied at the surface of the electrode. As another example, gas may be continuously or dynamically regenerated between the surface of the electrode and the assembly region.

[0024] In an exemplary embodiment, the liquid metal film may be maintained on the electrode's nosecone at a predetermined thickness in response to adjustments to the repetition rate of the discharge current and / or the rate of power generation. More specifically, the predetermined thickness may be dynamically maintained through adjustments to the flow rate of liquid metal from an internal reservoir within the electrode body to the surface of the nosecone. As an example, the flow rate may be maintained below an upper threshold flow rate above which excess liquid metal may form into droplets and separate from the surface of the nosecone that may adversely affect the confined plasma arc. As an additional or alternative example, the flow rate may be maintained above a lower threshold flow rate below which insufficient liquid metal may be present on the surface of the nosecone and significant electrode erosion may occur. In an exemplary embodiment, each of the upper and lower threshold flow rates may depend on the repetition rate of the discharge current and / or the rate of power generation such that a flow rate of liquid metal maintained between the upper and lower threshold flow rates may match the rate of liquid metal ablation from the surface of the nosecone.

[0025] One technical advantage of supplying and dynamically replenishing liquid metal on the nose cone in this manner is that as the liquid metal erodes during fusion reactor operation, it may be replaced, thereby reducing or completely eliminating electrode body erosion and allowing a fusion reactor including the electrodes to operate continuously for a year or more without electrode replacement.

[0026] Although the exemplary embodiments described in detail below with reference to FIGS. 1-9B may include a separate discussion of a static solid electrode including a metal hydride or an in-situ regenerable electrode including a liquid metal film, in other embodiments, an electrode (e.g., an inner electrode, an outer electrode, or an intermediate electrode) including a static solid electrode body including a metal hydride may be formed with a dynamically replenished liquid metal film on a nose cone of the electrode body. In an alternative embodiment, a first electrode (e.g., an outer electrode or an intermediate electrode) of the fusion reactor may be a static solid electrode including a metal hydride and another second electrode (e.g., an inner electrode) of the fusion reactor may be an in-situ regenerable electrode including a nose cone or other surface and a dynamically replenished liquid metal film on the nose cone or other surface. In such an embodiment, the second electrode may intersect with a confined plasma arc and a liquid metal film is provided on a nose cone or other surface of the second electrode to reduce or completely eliminate erosion of the second electrode body.

[0027] Further, in embodiments additional to, alternative to, or otherwise modified from those described in detail below with reference to Figures 1-9B, one or more components of the plasma confinement system may be added, removed, substituted, modified, or exchanged to adapt the plasma confinement system for a given use case. As an example, plasma may be directly injected into a plasma confinement chamber of a plasma confinement system, for example, in addition to or instead of in-chamber conversion of a fuel gas to plasma. Furthermore, although various embodiments described herein are discussed with reference to Z-pinch plasma confinement, the various embodiments, with or without modifications, may be applicable to other types of thermonuclear fusion reactors and plasma confinement systems that compress, react, or otherwise use plasma.

[0028] Referring now to FIG. 1, a schematic cross-sectional view of a plasma confinement system 300, such as may be included in a thermonuclear fusion reactor, is shown. The plasma confinement system 300 may generate a plasma arc in an assembly region 326 of a plasma confinement chamber 340, where the plasma arc is confined, compressed, and maintained by an axially symmetric magnetic field. The axially symmetric magnetic field may be stabilized by a shear ion velocity flow driven by an electrical discharge between a pair of electrodes interfacing with the plasma confinement chamber 340. FIGS. 2-3F discuss further operational details of the plasma confinement system 300. One or more aspects of the plasma confinement system 300 may be easily interchangeable with other plasma confinement structures, such as the plasma confinement system 900 detailed below with reference to FIG. 4.

[0029] In one embodiment, at least one of the pair of electrodes is a static solid electrode that includes an electrode material 346 that complements or augments thermonuclear fusion within the plasma confinement chamber 340 during the generation of a plasma arc. For example, the electrode material 346 may release hydrogen gas above a threshold temperature, for example, to provide a fuel gas for the plasma arc. Exemplary compositions of the electrode material 346 include metal deuterides and / or metals such as titanium (Ti), zirconium (Zr), scandium (Sc), magnesium (Mg), vanadium (V), lithium-6(Zn) and / or tungsten (Tg). 6 The metal hydride may be a metal hydride, such as a metal tritide containing one or more of the following metals (Li), or an alloy formed with any combination of one or more of the foregoing metals. Methods of forming such metal hydride-containing electrodes and using same to operate a plasma confinement system are discussed in detail below with reference to Figure 5. Ion implantation curves and isotherms for exemplary metal hydrides are provided in Figures 6 and 7, respectively.

[0030] In additional or alternative embodiments, at least one of the electrode pairs may be an in situ regenerable electrode that includes a protective film of flowing liquid metal that may ablate from the outer surface of the electrode upon interaction with the plasma arc, thereby mitigating high discharge erosion of the outer surface. Additional features of such in situ regenerable electrodes are discussed in detail below with reference to Figures 8A and 8B, and methods of operating a plasma confinement system including an in situ regenerable electrode are discussed in detail below with reference to Figures 9A and 9B.

[0031] A set of Cartesian coordinate axes 152 are shown in FIG. 1 to contextualize the positions of the various components of the plasma confinement system 300 and to compare the various views of FIG. 1 and FIG. 3A-3F. Specifically, mutually perpendicular x-, y-, and z-axes are provided, with the x- and y-axes defining the plane of the schematic cross-section shown in FIG. 1 and the z-axis perpendicular thereto. In some embodiments, the direction of gravity may be parallel to and coincident with any direction in the plane of the schematic cross-section of FIG. 1. For example, the direction of gravity may be parallel to and coincident with the positive direction of the x-axis. In additional or alternative embodiments, the direction of gravity may be in the plane defined by the y- and z-axes (e.g., parallel to and coincident with the negative direction of the y-axis).

[0032] In an exemplary embodiment, the plasma confinement system 300 may include an inner electrode 302 and an outer electrode 304 that substantially surrounds the inner electrode 302 (as the term "substantially" is used herein, the recited characteristic, parameter, or value need not be achieved exactly, but deviations and variations therein, including, for example, tolerances, measurement errors, measurement accuracy limitations, and other factors known to those of skill in the art, may occur in an amount that does not interfere with the effect the characteristic is intended to provide). For example, the inner electrode 302 may be at least partially circumferentially surrounded by the outer electrode 304, such that one end (e.g., first end 318) of the inner electrode 302 may be partially or completely surrounded by the outer electrode 304. In some embodiments, the inner electrode 302 may have a length (e.g., parallel to the y-axis and between the first end 318 and the opposing second end 320) in the range of 25 cm to 1 m or more, and a radius (e.g., parallel to the x-axis) in the range of 2 cm to 1 m, and the outer electrode 304 may have a length (e.g., parallel to the y-axis and between the first end 322 and the opposing second end 324) in the range of 50 cm to 6 m, a radius (e.g., parallel to the x-axis) in the range of 6 cm to 2 m or more, and an annular thickness (e.g., along the x-axis) in the range of 6 mm to 12 mm.

[0033] In certain embodiments, and as shown in Figure 1, the plasma confinement system 300 may further include an intermediate electrode 303 facing the inner electrode 302. In other embodiments, the intermediate electrode 303 may substantially surround the inner electrode 302 and the outer electrode 304 may substantially surround the intermediate electrode 303, as described in more detail below with reference to Figure 4. For example, the inner electrode 302 may be at least partially circumferentially surrounded by the intermediate electrode 303, and the intermediate electrode 303 may be at least partially circumferentially surrounded by the outer electrode 304, such that one end (e.g., first end 318) of the inner electrode 302 may be partially or completely surrounded by the intermediate electrode 303 and one end of the intermediate electrode 303 may be partially or completely surrounded by the outer electrode 304.

[0034] In some embodiments, the plasma confinement chamber 340 may be a physical structure that includes a volume bounded by one or more electrodes, insulators, and internal components of the plasma confinement system 300. Thus, in certain embodiments, the plasma confinement chamber 340 may include one or more electrodes, insulators, and internal components of the plasma confinement system 300 that define the volume of the plasma confinement chamber 340.

[0035] In an exemplary embodiment, the outer electrode 304 may define a radially outer boundary of the plasma confinement chamber 340. In one example, the radially outer boundary may be cylindrical and may be formed as a circular cross section propagating along the x-axis, the circular cross section being parallel to a plane formed by the y-axis and the z-axis. The plasma confinement chamber 340 may be divided (e.g., without a physical division) into an acceleration region 310 between the inner electrode 302 and the outer electrode 304, and an assembly region 326 between a first end 318 of the inner electrode 302 and the intermediate electrode 303. Alternatively, in an embodiment in which the intermediate electrode 303 at least partially surrounds the inner electrode 302, the acceleration region 310 may be between the inner electrode 302 and the intermediate electrode 303, and the assembly region 326 may be between the first end 318 of the inner electrode 302 and the opposing end of the outer electrode 304. In either case, the plasma confinement system 300 may include a plurality of electrodes (e.g., an inner electrode 302, an intermediate electrode 303, and an outer electrode 304), with each electrode of the plurality of electrodes disposed coaxially with respect to the assembly region 326 (e.g., parallel to the x-axis) and positioned so as to be exposed to the assembly region 326 (e.g., each given electrode of the plurality of electrodes may interface with the volume of the assembly region 326 without any intervening components or volumes, such that current can pass directly from the confined plasma to the given electrode). More specifically, the outer electrode 304 may be positioned to define at least a portion of an outer boundary of the assembly region 326, the inner electrode 302 may be positioned at one end of the assembly region 326 (e.g., coincident with the first end 318 of the inner electrode 302), and the middle electrode 303, when included, may be positioned at the same end of the assembly region 326 relative to the inner electrode 302 or at an opposite end of the assembly region 326 relative to the inner electrode 302. The plasma confinement system 300 may be configured to maintain a Z-pinch plasma (e.g., a plasma arc) within the assembly region 326, as described below.In some embodiments, the acceleration region 310 may have a length (e.g., parallel to the y-axis and between the second end 324 of the outer electrode 304 and the first end 318 of the inner electrode 302) in the range of 25 cm to 1.5 m and annular thickness in the range of 2 cm to 10 cm, and the assembly region 326 may have a length (e.g., parallel to the y-axis and between the first end 318 of the inner electrode 302 and the first end 322 of the outer electrode 304) in the range of 25 cm to 3 m.

[0036] The plasma confinement system 300 may include one or more first valves 306 configured to direct gas from within the inner electrode 302 to the acceleration region 310 and one or more second valves 312 configured to direct gas from outside the outer electrode 304 to the acceleration region 310. The gas may be a fuel gas, which may be utilized to form a plasma arc upon release of the gas into the plasma confinement chamber 340 and application of a discharge current. As used herein, "fuel gas" may refer to any species utilized to form a plasma arc. Thus, the fuel gas may be dihydrogen [e.g., hydrogen (H2), deuterium (D2), and / or tritium (T2)], 3 He, 6 Li, 11 The gas may include neutral gas species such as B, and / or pre-ionized gas species (e.g., introduced via a “direct plasma injection” or “plasma injection” configuration).

[0037] The plasma confinement system 300 may include a first power supply 314 configured to apply a voltage (e.g., in some embodiments, in the range of 2 kV to 50 kV, or in other embodiments, in the range of 1 kV to 40 kV) between the inner electrode 302 and the outer electrode 304. In some embodiments, the plasma confinement system 300 may further include a second power supply 315 configured to apply a voltage (e.g., in some embodiments, in the range of 2 kV to 50 kV, or in other embodiments, in the range of 1 kV to 40 kV) between the inner electrode 302 and the intermediate electrode 303. In certain embodiments, the plasma confinement system 300 may operate with only one of the first power supply 314 and the second power supply 315. In other embodiments, the plasma confinement system 300 may operate with at least both the first power supply 314 and the second power supply 315. In some embodiments, one or both of the first power source 314 and the second power source 315 may include a switching pulsed direct current (switching pulsed DC) power source including an energy source (e.g., a capacitor bank), a switch (e.g., a spark gap, ignitron, or semiconductor switch), and a pulse shaping network (e.g., including inductors, resistors, diodes, etc.). In some embodiments, one or both of the first power source 314 and the second power source 315 may be voltage controlled. In other embodiments, one or both of the first power source 314 and the second power source 315 may be current controlled. In some embodiments, other suitable types of power sources may be used as one or both of the first power source 314 and the second power source 315, including DC and alternating current (AC) power sources (e.g., DC grids, voltage source converters, homopolar generators, etc.).

[0038] The inner electrode 302 may include a conductive (e.g., stainless steel) shell having a modified cylindrical body 316 (e.g., substantially cylindrical with a tapered rounded base at a first end 318). Specifically, the inner electrode 302 may include a first end 318 (e.g., tapered rounded base) and an opposing second end 320 (e.g., substantially flat circular base). For example, the inner electrode 302 may include a nose cone 344 positioned at the first end 318, the nose cone 344 exposed to the assembly region 326 to intersect with an axis of the confined plasma arc that is coaxial with each electrode of the plurality of electrodes (e.g., parallel to the x-axis). In an exemplary embodiment, the nose cone 344 may include an electrode material 346 that complements or augments thermonuclear fusion within the plasma confinement chamber 340 during the generation of the plasma arc (e.g., via release of hydrogen gas to fuel the confined plasma arc). However, in other embodiments, the electrode material 346 is not limited to the nose cone 344, but may additionally be included on another portion of the inner electrode 302 and / or on any other electrode of the plurality of electrodes (thus, in certain embodiments, the electrode material 346 may not be included on the nose cone 344 at all). In either case, the electrode material 346 may occupy only a portion of one or more electrodes of the plurality of electrodes, and the remaining portions (e.g., all portions of the plurality of electrodes except for the portion occupied by the electrode material 346) may be free of the electrode material 346. Thus, when the electrode material 346 is included, the fuel gas may be discharged into the acceleration region 310 in response to heating one or more of the inner electrode 302, the intermediate electrode 303, or the outer electrode 304 (e.g., such that the electrode material 346 pyrolyzes to release the fuel gas). The inner electrode 302 may further include one or more conduits or channels 342 for routing gas (e.g., fuel gas) from the one or more first valves 306 to the acceleration region 310, for example, during operation of the plasma confinement system 300 to generate thermonuclear fusion.

[0039] In additional or alternative embodiments, the electrode material 346 may exist as a filament separate from any of the electrodes in the plasma confinement system 300. In such embodiments, the electrode material 346 may provide at least a portion of the fuel gas to the plasma confinement chamber 340 upon heating and pyrolysis thereof.

[0040] The outer electrode 304 may include a conductive (e.g., stainless steel) shell having a substantially cylindrical body 328. Specifically, the outer electrode 304 may include a first end 322 (e.g., a substantially flat circular base) and an opposing second end 324 (e.g., a substantially flat circular base). The outer electrode 304 may surround most (e.g., a majority) of the inner electrode 302. In an exemplary embodiment, the inner electrode 302 and the outer electrode 304 may be concentric and have radial symmetry with respect to the x-axis. The first end 318 of the inner electrode 302 may be between the first end 322 of the outer electrode 304 and the second end 324 of the outer electrode 304. The outer electrode 304 may further include one or more conduits or channels (not shown in FIG. 1 ) for routing gas (e.g., fuel gas) from the one or more second valves 312 to the acceleration region 310, for example, during operation of the plasma confinement system 300 to generate thermonuclear fusion.

[0041] The intermediate electrode 303 may include a conductive material (e.g., stainless steel). In some embodiments, the intermediate electrode 303 may be substantially disk-shaped. In other embodiments, the intermediate electrode may have a substantially cylindrical body that is concentric with each of the inner electrode 302 and the outer electrode 304 and has radial symmetry about the x-axis.

[0042] The one or more first valves 306 may take the form of a so-called "puff valve" (e.g., operable to provide fuel gas for the formation of a plasma or to increase the density of a plasma arc generated via a gas puff) or a plasma injector. In additional or alternative embodiments, the one or more first valves 306 may include at least one electrically actuated valve, such as a solenoid-driven valve. However, the one or more first valves 306 are not limited to such configuration and may include any type of valve configured to direct gas (e.g., H2, D2, T2) from within the inner electrode 302 to the acceleration region 310.

[0043] In some embodiments, the one or more first valves 306 may be mounted in a regular array along the inner electrode 302 (e.g., regularly distributed around the central axis of the acceleration region 310) and may include at least one gas puff valve (e.g., for providing neutral gas to the acceleration region 310) and / or at least one plasma injector (e.g., for providing pre-ionized gas to the acceleration region 310). As shown in FIG. 1, the one or more first valves 306 may be positioned (e.g., axially positioned) between the first end 318 of the inner electrode 302 and the second end 320 of the inner electrode 302. Alternatively, the one or more first valves 306 may be positioned (e.g., directly adjacent) to the first end 318 of the inner electrode 302 or the second end 320 of the inner electrode 302. 1, each of the one or more first valves 306 is disposed within the inner electrode 302 (e.g., positioned within and on the inner inner surface), although other implementations are possible (e.g., positioned on the outer and outer surfaces of the inner electrode 302). The one or more first valves 306 may be electrically actuable in that the one or more first valves 306 may be operated by providing a control voltage to the one or more first valves 306, as described below. In certain embodiments in which an electrode material 346 is included, a first valve 306 is not included (e.g., the electrode material 346 may provide at least a portion of the gas upon its decomposition).

[0044] In an exemplary embodiment, the acceleration region 310 may have a substantially annular cross-section defined by the shapes of the inner electrode 302 and the outer electrode 304. Specifically, the inner electrode 302 may define a radially inner boundary of the acceleration region 310, and the outer electrode 304 may define a radially outer boundary of the acceleration region 310. In one example, each of the radially inner and outer boundaries may be cylindrical and formed as a circular cross-section propagating along the x-axis, the circular cross-section being parallel to a plane formed by the y-axis and the z-axis. In other embodiments, the substantially annular cross-section of the acceleration region 310 may be defined by the shapes of the inner electrode 302 and the intermediate electrode 303 (e.g., the inner electrode 302 may define a radially inner boundary, and the intermediate electrode 303 may define a radially outer boundary).

[0045] In the same manner as the one or more first valves 306, the one or more second valves 312 may take the form of a puff valve or a plasma injector. In additional or alternative embodiments, the one or more second valves 312 may include at least one electrically actuated valve, such as a solenoid actuated valve. However, the one or more second valves 312 are not limited to such configuration and may include any type of valve configured to direct gas (e.g., H2, D2, and / or T2) from outside the outer electrode 304 (or intermediate electrode 303) to the acceleration region 310.

[0046] In some embodiments, the one or more second valves 312 may be installed in a regular array along the outer electrode 304 (e.g., regularly distributed around the acceleration region 310) and may include at least one gas puff valve (e.g., for providing neutral gas to the acceleration region 310) and / or at least one plasma injector (e.g., for providing pre-ionized gas to the acceleration region 310). As shown in FIG. 1, the one or more second valves 312 may be positioned (e.g., axially positioned) between the first end 322 of the outer electrode 304 and the second end 324 of the outer electrode 304. Alternatively, the one or more second valves 312 may be positioned (e.g., directly adjacent) to the first end 322 of the outer electrode 304 or the second end 324 of the outer electrode 304. In FIG. 1, each of the one or more second valves 312 is disposed around the outer electrode 304 (e.g., positioned on an outer and outer surface), although other implementations are possible (e.g., positioned within the plasma confinement chamber 340, such as on the inner surface of the outer electrode 304 or on the inner surface of the intermediate electrode 303). Additionally, in FIG. 1, each of the one or more first valves 306 is axially aligned with each of the one or more second valves 312, although other implementations are possible. The one or more second valves 312 may be electrically actuable in that the one or more second valves 312 may be operated by providing a control voltage to the one or more second valves 312, as described below. In certain embodiments in which an electrode material 346 is included, a second valve 312 is not included (e.g., the electrode material 346 may provide at least a portion of the gas upon its decomposition).

[0047] In some embodiments, the gas puff valves and / or plasma injectors included in one or more of the first valves 306 and / or one or more of the second valves 312 may be electronically triggered to independently deliver "puffs" of neutral and / or ionized gas fill for durations lasting up to hundreds of μs (e.g., up to 1 millisecond). The amount of fill gas (also referred to herein as "fuel gas") delivered (e.g., in a "puff") may also be controlled by adjusting the fill gas pressure supplied to the gas puff valves and / or plasma injectors (e.g., one or all of the gas puff valves and / or plasma injectors or a subset thereof). Furthermore, different gas puff valves and / or plasma injectors (or different combinations of multiple gas puff valves and / or plasma injectors) may be supplied with different fill gas mixtures, e.g., with fill gases of different elemental ratios and / or different isotopic ratios (e.g., adjustable D2 / T2 molecular ratios). In some embodiments, the gas puff valves and / or plasma injectors may be uniform (e.g., all of the same type / size with substantially the same operational settings). In other embodiments, different gas puff valves and / or plasma injectors may be used for different locations. In additional or alternative embodiments, the gas puff valves and / or plasma injectors may control the flow of gas into the acceleration region 310 via a manifold that includes multiple ports that provide passage into the acceleration region 310. In such embodiments, the ports of the manifold may be uniform or may vary in configuration (e.g., to deliver different amounts of gas to different locations of the acceleration region 310 when each gas puff valve or plasma injector is open).

[0048] Similar to neutral gas injection via gas puff valves, (pre)ionized gas or plasma may be injected using a combination or manifold of plasma injectors at various positions fluidly connected to the respective plasma generators or guns that generate the plasma prior to injection into the acceleration region 310. In some embodiments, the plasma may be supplied from a gas injection washer plasma gun and / or a plasma thruster (e.g., Hall effect thruster or magnetohydrodynamic thruster), or, if the plasma is magnetized, from a high-power helicon plasma source, a radio frequency plasma source, a plasma torch, and / or a laser-based plasma source. Plasmas formed from gas mixtures may also be generated and injected in a manner similar to neutral gas injection. Plasma injection may provide finer control of the final axial plasma distribution, as well as its shear flow profile, which may allow for higher fidelity control of plasma stability and lifetime. Further control of plasma injection may be provided because the plasma particles are charged particles that may be accelerated by an electric field generated by a variable electrical bias (or voltage) on the injection electrode. Thus, the velocity of the injected plasma may be finely controlled to allow fine tuning and optimization of the destruction of any neutral gas present (e.g., in the acceleration region 310). Furthermore, the injected plasma may move at a faster velocity than the injected neutral gas, which may move in a nearly static manner (compared to the injected plasma) during the Z-pinch discharge pulse. Thus, relative to neutral gas injection, plasma injection may provide pre-ionized fuel "on demand (e.g., more immediately)," for example, to replenish fuel gas during the Z-pinch discharge pulse.

[0049] In some embodiments, the pre-ionized gas may be generated as a non-magnetized plasma, e.g., to avoid interactions between the magnetic field of the pre-ionized gas and the magnetic field of the acceleration region 310. In other embodiments, the pre-ionized gas may be generated as a magnetized plasma, e.g., to align the magnetic field of the pre-ionized gas parallel to the magnetic field of the acceleration region 310 and / or be adjustable to provide a desired magnetic flux profile at the injection point of the pre-ionized gas.

[0050] In some embodiments, the plasma injected into the acceleration region 310 may be generated by pre-ionizing a neutral gas with a spark plug or via inductive ionization. More broadly, the gas puff valve and / or plasma injector may include one or more electrode plasma injectors and / or one or more electrodeless plasma injectors. In examples including one or more electrode plasma injectors, the plasma injected into the acceleration region 310 may be generated, at least in part, by an electrode discharge. In additional or alternative examples including one or more electrodeless plasma injectors, the plasma injected into the acceleration region 310 may be generated, at least in part, by an inductive discharge generated by an external coil window (e.g., a radio frequency antenna operating at 400 kHz, 13.56 MHz, 2.45 GHz, and / or other frequencies permitted for use in a given local jurisdiction, e.g., within the frequency range permitted by the Federal Communications Commission). In some embodiments, the neutral gas for pre-ionization may be limited by the conductance of the neutral gas to a neutral gas reservoir (eg, gas source 330) and / or a selected plasma injector configuration.

[0051] In some embodiments, axial distribution of the injected plasma may be ensured via an axisymmetric plasma injector configuration. In at least one embodiment, eight plasma injectors may be positioned at eight equally spaced ports of the manifold, respectively. Each of the eight ports may be configured at an oblique angle (e.g., 5° to 90° relative to the central axis of the acceleration region 310) relative to the housing of the acceleration region 310 (e.g., the surrounding outer electrode 304). In one example, the oblique angle may be 45° relative to the central axis of the acceleration region 310. In some embodiments, the eight ports may be configured at a single axial location along the central axis of the acceleration region 310 (i.e., the eight ports may be evenly spaced around the circumference or other periphery of the acceleration region 310 at axial locations). In other embodiments, the ports may include multiple sets of eight ports, with each set of eight ports evenly spaced around a different axial location along the central axis of the acceleration region 310. In an exemplary embodiment, the sets of eight ports may be configured as pairs of interleaved sets, with a first set of eight ports positioned at a first axial location and a second set of eight ports positioned at a second different axial location and rotated relative to the first set such that each port of the second set is positioned between a pair of ports of the first set relative to the circumference of the acceleration region 310. Specifically, in such an embodiment, each port of the first set of eight ports may be spaced around the circumference of the acceleration region 310 every 45 degrees, and each port of the second set of eight ports may be spaced around the circumference of the acceleration region 310 every 22.5 degrees offset (rotation) from the ports of the first set, such that one port of the first set and one port of the second set are provided around the circumference of the acceleration region 310 every 22.5 degrees. In additional or alternative embodiments, plasma injection may be performed azimuthally, for example along a chord perpendicular to the central axis of the acceleration region 310, to generate azimuthal flow within the acceleration region 310.In some embodiments, additional gas puff valves and / or plasma injectors may be included to allow for injection of more fuel gas (e.g., for a longer sustained pinch discharge) and control of the axial pressure distribution of the fuel gas within the acceleration region 310 (e.g., for further enhancement of the duration of the shear ion velocity flow). In additional or alternative embodiments, the valves may be configured differently (e.g., asymmetrically azimuthally distributed and / or have a different angular distribution) with other deformations to achieve a substantially equivalent profile by compensating for the effects of the deformations.

[0052] In some embodiments, injecting the acceleration region 310 with the pre-ionized gas may result in a plasma with a plasma temperature in the range of 1-10 eV. The plasma temperature may be decreased (e.g., by reducing the amount of energy input into the process gas used to generate the pre-ionized gas) to increase the electrical resistivity of the pre-ionized gas and the resulting plasma. Specifically, increasing the electrical resistivity may reduce the tendency of the pre-ionized gas to oppose changes in magnetic flux, thereby reducing the tendency of the pre-ionized gas to oppose movement in the magnetic field present in the acceleration region 310.

[0053] As mentioned above, the injection velocity of the pre-ionized gas may be significantly greater than the injection velocity of the neutral gas, so that the velocity of the plasma in the acceleration region 310 can be up to 50×10 3 m / s. In some embodiments, the injection of pre-ionized gas may provide flexibility in the amount of particles injected. Specifically, in an exemplary embodiment, a volume of pre-ionized gas particles may be injected in 1 / 50 of the time utilized to inject the same volume of neutral gas particles. For example, the time utilized to inject 10 Torr-L of neutral gas particles (1 Torr-L is 2.5×10 at 273 K) may be 1 / 50 of the time utilized to inject 10 Torr-L of neutral gas particles (1 Torr-L is 2.5×10 at 273 K). 19The time (proportional to the numerator) may be the same amount of time utilized to inject 500 Torr-L of pre-ionized gas particles. Similarly, in some embodiments, the injection rate (or mass flow rate) of the pre-ionized gas may be varied depending on the power supply current and voltage (i.e., the waveform of the injection pulse). As one example, increasing the power supply voltage (e.g., 100V to 500V) may simultaneously increase the injection rate. As another example, increasing the power supply current (e.g., 1A to 500A) may simultaneously increase the injection rate. In some embodiments, the power supply voltage may be increased from 750V to 5kV.

[0054] As described above, the gas puff valves and / or plasma injectors may be activated individually or as groups. An initial gas load inside the acceleration region 310 having a desired axial and azimuthal profile may be achieved by timing individual valves and / or groups of valves. Such valves (or groups of them) may be timed in a manner to match the arrival of neutral gas and / or pre-ionized gas and / or mixtures thereof to the desired initial profile. Power supplies (e.g., power supplies 314 and 315 or a separate dedicated power supply) may be timed to achieve ionization at a desired axial location and utilize the initial gas load to create and maintain the shear flow. In some embodiments, the power supplies may include a capacitor bank and a switch. In other embodiments, other suitable types of power supplies may be used, including flywheel power supplies.

[0055] Various combinations of the (neutral gas) gas puff valve with the plasma injector may be activated to achieve the desired level of power output. Furthermore, the plasma may be injected into the acceleration region 310 significantly (e.g., about 100 times) faster than the puffed neutral gas. Such combinations of different injection rates allowed by the acceleration of plasma injection with neutral gas injection provide an even larger parameter space for optimization. Additionally, the plasma injector may serve to inject mass and precisely control the location of neutral gas ionization.

[0056] In an exemplary embodiment, first power source 314 and second power source 315 may take the form of respective capacitor banks each capable of storing up to 10 MJ (e.g., 0.1-10 MJ). In one embodiment, first power source 314 and second power source 315 take the form of respective capacitor banks capable of storing up to 100-200 kJ and 3-4 MJ, respectively.

[0057] The plasma confinement system 300 may include a gas source 330 (e.g., a pressurized storage tank) and one or more first controllers 332 each configured to control gas flow from the gas source 330 through one or more first valves 306. For clarity, the respective couplings (e.g., piping) between the one or more first controllers 332 and the one or more first valves 306 are omitted in FIG.

[0058] Similarly, the plasma confinement system 300 may include one or more second regulators 334 each configured to control gas flow from the gas source 330 through the one or more second valves 312. For clarity, the respective connections (e.g., piping) between the one or more second regulators 334 and the one or more second valves 312 are omitted in FIG.

[0059] In some embodiments, the plasma confinement system 300 may include a first insulator 336 (e.g., having an annular cross-section) between the inner electrode 302 and the outer electrode 304 to maintain electrical insulation between the inner electrode 302 and the outer electrode 304. In other embodiments, such as when the inner electrode 302 is at least partially surrounded by the intermediate electrode 303, the first insulator 336 may be positioned between the inner electrode 302 and the intermediate electrode 303 to maintain electrical insulation between the inner electrode 302 and the intermediate electrode 303. In an exemplary embodiment, the first insulator 336 may be formed from an electrically insulating material, such as a glass, ceramic, or glass-ceramic material. In some embodiments, one or more valves (e.g., gas puff valves and / or plasma injectors) may extend through the first insulator 336 or be provided in place of the first insulator 336 to inject neutral gas and / or pre-ionized gas into an end of the acceleration region 310 opposite the first end 318 of the inner electrode 302.

[0060] Similarly, the plasma confinement system 300 may include a second insulator 337 (e.g., having an annular cross-section) between the intermediate electrode 303 and the outer electrode 304 to maintain electrical insulation between the intermediate electrode 303 and the outer electrode 304. In an exemplary embodiment, the second insulator 337 may be formed from an electrically insulating material, such as a glass, ceramic, or glass-ceramic material.

[0061] The plasma confinement system 300 may include a vacuum chamber 338 that at least partially surrounds the inner electrode 302, the intermediate electrode 303, and / or the outer electrode 304. In the exemplary embodiment shown in FIG. 1, the vacuum chamber 338 completely surrounds each of the inner electrode 302, the intermediate electrode 303, and the outer electrode 304 (and thereby the plasma confinement chamber 340). In the exemplary embodiment, the vacuum chamber 338 may be formed as a stainless steel pressure vessel. In some embodiments, the pressure within the vacuum chamber 338 may be greater than 10 -9 Torr~20 Torr (e.g., 10 -9 Torr~10 -3 Torr).

[0062] The plasma confinement system 300 may include a controller or other computing device 348, which may include non-transitory memory in which executable instructions may be stored. The executable instructions may be executed by one or more processors of the controller 348 to perform various functions of the plasma confinement system 300. Thus, the executable instructions may include various routines for operation, maintenance, and testing of the plasma confinement system 300. The controller 348 may further include a user interface through which an operator of the plasma confinement system 300 may enter commands or otherwise modify the operation of the plasma confinement system 300. The user interface may include various components for facilitating operator use of the plasma confinement system 300 and for receiving operator input (e.g., a request to generate a plasma arc for thermonuclear fusion), such as one or more displays, input devices (e.g., keyboards, touch screens, computer mice, depressible buttons, mechanical switches, other mechanical actuators, etc.), lights, etc. A controller 348 may be communicatively coupled to various components (e.g., valves, power supplies, etc.) of the plasma confinement system 300 to command their operation and use (for clarity, wired and / or wireless communication paths between the controller 348 and the various components are omitted in FIG. 1 ).

[0063] Referring now to Figures 2-3F, operational aspects of a plasma confinement system, such as the plasma confinement system 300 described in detail above with reference to Figure 1, are illustrated. Specifically, in Figure 2, a block diagram of a method 200 for operating a plasma confinement system is illustrated, and Figures 3A-3F respectively illustrate a schematic cross-sectional view of a portion 350 of the plasma confinement system 300 of Figure 1 and its functionality. Thus, Figures 1 and 3A-3F, when viewed together, illustrate at least some of the aspects of the method 200 described below. In an exemplary embodiment, operation of a plasma confinement system (e.g., plasma confinement system 300) may include initiating and driving a shear ion velocity flow therein for stabilization of a Z-pinch discharge.

[0064] In some embodiments, method 200, or portions thereof, may be implemented as executable instructions stored in a non-transitory memory of a computing device, such as a controller communicatively coupled to the plasma confinement system. Furthermore, in certain embodiments, additional or alternative sequences of steps may be implemented as executable instructions on such a computing device, and individual steps discussed with reference to method 200 may be added, removed, substituted, modified, or replaced.

[0065] At block 902, the method 200 may include directing gas from within the inner electrode to an acceleration region of the plasma confinement chamber via one or more first valves. In an exemplary embodiment, the acceleration region may be located between the inner electrode and an outer electrode that substantially surrounds the inner electrode. In other embodiments, the acceleration region may be disposed between the inner electrode and an intermediate electrode that substantially surrounds the inner electrode, with the outer electrode substantially surrounding the intermediate electrode.

[0066] 3A and 3B, one or more first valves 306 can direct gas 912 from within the inner electrode 302 to an acceleration region 310 between the inner electrode 302 and an outer electrode 304 that substantially surrounds the inner electrode 302. Specifically, FIG. 3A illustrates an initial amount of gas 912 entering the acceleration region 310, and FIG. 3B illustrates an additional amount of gas 912 entering the acceleration region 310. As shown in FIG. 3A, region 310 may be contained within a plasma confinement chamber 340 along with an assembly region 326.

[0067] In some embodiments, directing the gas 912 through the one or more first valves 306 includes providing a first valve voltage to the one or more first valves 306 (e.g., via a power source such as a capacitor bank not shown in FIGS. 3A-3F) (e.g., to control terminals of the one or more first valves 306), followed by providing a second valve voltage [e.g., via a DC power source] to the one or more first valves 306. In an exemplary embodiment, the first valve voltage may be greater than the second valve voltage, and the second valve voltage may be provided immediately (e.g., substantially immediately) after providing the first valve voltage.

[0068] At block 904, the method 200 may include directing gas from outside the outer electrode to the acceleration region via one or more second valves.

[0069] For example, as shown in FIGS. 3A and 3B, one or more second valves 312 can direct a portion of the gas 912 to the acceleration region 310.

[0070] In some embodiments, directing the gas 912 through one or more second valves 312 (e.g., via a power source such as a capacitor bank, not shown) may include providing a third valve voltage to one or more second valves 312 (e.g., to control terminals of one or more second valves 312), followed by providing a fourth valve voltage (e.g., via a DC power source) to the one or more second valves 312. In an exemplary embodiment, the third valve voltage may be greater than the fourth valve voltage, and the fourth valve voltage may be provided immediately (e.g., substantially immediately) after providing the third valve voltage.

[0071] After operation of the one or more first valves 306 and the one or more second valves 312, e.g., immediately adjacent (when released) or within (e.g., within a plenum, if present) each of the one or more first valves 306 and the one or more second valves 312, may be up to 5800 Torr, such as in the range of 1000-5800 Torr (e.g., 5450-5550 Torr), prior to applying a voltage between the inner electrode 302 and the outer electrode 304 via the first power supply 314. Accordingly, after operation of the one or more first valves 306 and the one or more second valves 312, the gas pressure in the acceleration region 310 may be up to 5800 Torr, such as in the range of 1000-5800 Torr (e.g., 5450-5550 Torr), prior to applying a voltage between the inner electrode 302 and the outer electrode 304 via the first power supply 314. In an exemplary embodiment, the gas pressure within the acceleration region 310 may decrease with increasing distance from the gas insertion point and with time after gas is no longer introduced into the acceleration region 310.

[0072] In block 906, the method 200 may include applying a voltage between the inner electrode and the outer electrode via a first power supply to convert at least a portion of the directed gas into a plasma having a substantially annular cross-section, the plasma flowing axially within the acceleration region toward the first end of the inner electrode and the first end of the outer electrode.

[0073] For example, as shown in FIGS. 3C and 3D, the first power supply 314 may apply a voltage between the inner electrode 302 and the outer electrode 304 to convert at least a portion of the gas 912 into a plasma 916 having a substantially annular cross-section. The voltage applied by the first power supply 314 between the inner electrode 302 and the outer electrode 304 may result in a radial electric field in the acceleration region 310 of up to 500 kV / m (e.g., in a range of 30 kV / m to 500 kV / m). Due to a magnetic field generated by a current traveling through the plasma 916, the plasma 916 may flow axially in the acceleration region 310 toward a first end 318 of the inner electrode 302 and a first end 322 of the outer electrode 304 (as shown in FIGS. 3C and 3D).

[0074] At block 908, the method 200 may include applying a voltage between the inner electrode and the intermediate electrode via the second power supply to establish a plasma arc (e.g., a Z-pinch plasma) flowing between the intermediate electrode and a first end of the inner electrode. In an exemplary embodiment, the intermediate electrode may be positioned at a first end of the outer electrode. In other embodiments, and as previously described, the intermediate electrode may substantially surround the inner electrode and the outer electrode may substantially surround the intermediate electrode.

[0075] For example, with reference to Figures 3E and 3F, a second power source (e.g., the second power source 315 described in detail above with reference to Figure 1, omitted in Figures 3A-3F for clarity) may apply a voltage between the inner electrode 302 and the intermediate electrode 303 to confine the plasma 916 and establish a plasma arc 918 (also referred to herein as a Z-pinch plasma 918) that flows between the intermediate electrode 303 and a first end 318 of the inner electrode 302. As shown, the plasma arc 918 may be established as the plasma 916 travels beyond the acceleration region 310. Specifically, the plasma arc 918 may flow into the assembly region 326 between the first end 318 of the inner electrode 302 and the intermediate electrode 303. In some embodiments, for example, when the inner electrode 302 functions as a cathode and the intermediate electrode 303 functions as an anode, the discharge current forming the plasma arc 918 and the shear axial (ion velocity) flow stabilizing the discharge current may each flow from the first end 318 of the inner electrode 302 to the intermediate electrode 303. In other embodiments, such as when the inner electrode 302 functions as an anode and the intermediate electrode 303 functions as a cathode, the discharge current may flow from the intermediate electrode 303 to the first end 318 of the inner electrode 302 and the shear axial flow may flow from the first end 318 of the inner electrode 302 to the intermediate electrode 303. In some embodiments, injection of pre-ionized gas using a plasma injector, plasma gun, or ion source may also be employed in conjunction to enhance the shear flow profile created by the neutral gas injection. Thus, in such an embodiment, plasma injection may occur quickly, on the same scale as blocks 902 and 904, and may be used to control the formation / initialization and dynamics of the plasma arc 918.

[0076] In an exemplary embodiment, the plasma arc 918 may exhibit a sheared axial flow, a radius of up to 5 mm (e.g., 0.05-5 mm), an ion temperature of up to 100,000 eV, e.g., 900-30,000 eV (e.g., 900-2,000 eV), an electron temperature of over 500 eV, and an electron temperature of over 1×10 23 ions / m 3Ion number density exceeding 1×10 23 electron / m 3 and / or a magnetic field of more than 8 T, and / or stable for at least 1 μs, e.g., 5-10 μs or up to 1 ms. It should be noted that such ranges are exemplary and may be modified based on the mode of operation of the plasma confinement system 300 or based on modifications to the size, functionality, configuration, etc. of the plasma confinement system 300. For example, if the size of the plasma confinement system 300 is increased, such ranges may scale proportionately (e.g., linearly, exponentially, etc.).

[0077] It should be noted that blocks 906 and 908 may be implemented by other means of controlling (a) the voltage between the inner electrode 302 and the outer electrode 304, and (b) the voltage between the inner electrode 302 and the intermediate electrode 303, as one of ordinary skill in the art would recognize. For example, a power source may provide a voltage between the intermediate electrode 303 and the outer electrode 304 instead of between the inner electrode 302 and the intermediate electrode 303.

[0078] 4, a schematic cross-sectional view of a plasma confinement system 900, such as may be included in a thermonuclear fusion reactor, is shown. The plasma confinement system 900 may generate a plasma arc in an assembly region 630 of a plasma confinement chamber 610, where the plasma arc is confined, compressed, and maintained by an axially symmetric magnetic field. The axially symmetric magnetic field may be stabilized by a shear ion velocity flow driven by an electrical discharge between a pair of electrodes interfacing with the plasma confinement chamber 610.

[0079] The plasma confinement system 900 may be assembled and configured similarly to the plasma confinement system 300, and may in fact operate in a substantially similar manner. The primary differences between the plasma confinement system 300 illustrated in FIG. 1 and the plasma confinement system 900 illustrated in FIG. 4 include the relative positioning and spatial configuration of the intermediate electrode 303 (FIG. 1) and the relative positioning and spatial configuration of the intermediate electrode 920 (FIG. 4), which will be discussed in more detail below. Except for certain assembly and operational aspects that may result from such differences, the descriptions provided above with reference to FIGS. 1-3F may additionally apply to the embodiment illustrated in FIG. 4. In certain embodiments, additional subsystems and / or functions may also be included in the plasma confinement system 900 that are not described in detail above with reference to FIGS. 1-3F, and may additionally apply to the embodiment illustrated in FIG. 1-3F.

[0080] Thus, in one embodiment, at least one of the electrode pairs driving the shear ion velocity flow is a static solid electrode that includes an electrode material that complements or augments thermonuclear fusion within the plasma confinement chamber 610 during the generation of a plasma arc. In additional or alternative embodiments, at least one of the electrode pairs may be an in situ regenerable electrode that includes a protective film of flowing liquid metal that may ablate from the outer surface of the electrode upon interaction with the plasma arc, thereby mitigating high discharge erosion of the outer surface.

[0081] To contextualize the positions of the various components of the plasma confinement system 900, a set of Cartesian coordinate axes 452 are shown in FIG. 4. Specifically, mutually perpendicular x-axis, y-axis, and z-axis are provided, with the x-axis and y-axis defining a plane of the schematic cross-section shown in FIG. 4 and the z-axis perpendicular thereto. In some embodiments, the direction of gravity may be parallel to and coincident with any direction in the plane of the schematic cross-section of FIG. 4. For example, the direction of gravity may be parallel to and coincident with the positive direction of the x-axis. In additional or alternative embodiments, the direction of gravity may be in the plane defined by the y-axis and z-axis (e.g., parallel to and coincident with the negative direction of the y-axis).

[0082] In an exemplary embodiment, the plasma confinement system 900 may include an outer electrode 650 that is physically and functionally separated from an external vacuum boundary 910 that, together with a portion of the inner electrode 660, forms the vacuum vessel 640 as a low pressure vessel that includes the plasma confinement chamber 610. The intermediate electrode 920 may be positioned to have a radius between a radius of the inner electrode 660 and a radius of the outer electrode 650. Specifically, the intermediate electrode 920 may substantially surround the inner electrode 660, and the outer electrode 650 may substantially surround the intermediate electrode 920. For example, the inner electrode 660 may include one end 665 at least partially surrounded by the intermediate electrode 920, and the intermediate electrode 920 may include one end 965 at least partially surrounded by the outer electrode 650.

[0083] The plasma confinement system 900 includes at least two functionally separate power sources, e.g., a Z-pinch (discharge) current 950 (I pinch ) and at least one additional power source 940 primarily arranged and controlled to drive the residual current 867. In some embodiments, the at least one primary power source 930 may be a separate power supply from the at least one additional power source 940. In other embodiments, the at least one primary power source 930 and the at least one additional power source 940 may be components of the same power supply.

[0084] For example, in at least one embodiment, a single power supply may have multiple outputs that separately provide amounts of power to enable performance of respective functions (e.g., driving Z-pinch current 950, driving residual current 867, etc.). Such an arrangement may be based on at least two power sources (e.g., one primary power source 930 and one additional power source 940) and may allow additional control of Z-pinch current 950 and its shear flow stabilization. In principle, the at least two power sources may be scaled, charged, and controlled such that the Z-pinch current 950 and its stabilization may be maintained for a reasonable period of time before any of the at least two power sources prematurely runs out or depletes its stored energy.

[0085] In certain embodiments, the plasma confinement system 900 may incorporate a "tapered electrode" configuration characterized by widening the gap between the inner electrode 660 and the intermediate electrode 920 by tapering the end 965 of the intermediate electrode 920 outwardly along the x-axis to increase the volume of at least a portion of the acceleration region 620 in the direction of the (unsupported) ends 665 and 965. In one example, the taper may be 0-15° from the central axis of the plasma confinement system 900 (e.g., parallel to the x-axis). Such an arrangement may facilitate the transfer of momentum from the plasma heated by the residual current 867 to the neutral gas, e.g., along the positive direction of the x-axis, thereby creating and maintaining shear flow stabilization. The momentum transfer may be described and modeled using methodologies applicable to the design / optimization of "Laval nozzles," as known in the jet propulsion arts.

[0086] Although the techniques described herein are discussed in connection with the exploitation of thermonuclear fusion and, for example, energy generation therefrom, the techniques described herein can be used for other purposes such as heat generation (e.g., manufacturing utilizing relatively high temperatures) and propulsion. For example, the plasma confinement system 300 of FIG. 1 or the plasma confinement system 900 of FIG. 4 may be modified by removing at least the vacuum chamber 338 or the outer vacuum boundary 910, respectively, and introducing an opening at one end of the outer electrode 650 to allow the fusion products to escape (e.g., parallel to the x-axis). In one embodiment, a magnetic nozzle (not shown in FIG. 4) is positioned downstream of the outer electrode 650, for example, to the right of the outer electrode 650 with respect to the x-axis, to collimate the plasma and reduce the divergence of any exhaust plume.

[0087] The plasma confinement system 900 may include a controller or other computing device 948, which may include a non-transitory memory in which executable instructions may be stored. The executable instructions may be executed by one or more processors of the controller 948 to perform various functions of the plasma confinement system 900. Thus, the executable instructions may include various routines for operation, maintenance, and testing of the plasma confinement system 900. The controller 948 may further include a user interface through which an operator of the plasma confinement system 900 may enter commands or otherwise modify the operation of the plasma confinement system 900. The user interface may include various components for facilitating operator use of the plasma confinement system 900 and for receiving operator input (e.g., a request to generate a plasma arc for thermonuclear fusion), such as one or more displays, input devices (e.g., keyboards, touch screens, computer mice, depressible buttons, mechanical switches, other mechanical actuators, etc.), lights, etc. A controller 948 may be communicatively coupled to various components (e.g., valves, power supplies, etc.) of the plasma confinement system 900 to command their operation and use (for clarity, wired and / or wireless communication paths between the controller 948 and the various components are omitted in FIG. 4 ).

[0088] 5, there is shown a block diagram of a method 400 for operating a plasma confinement system, such as any of the plasma confinement systems described in detail above with reference to FIGS. 1-4, and forming electrodes therefor, where the electrodes may be formed of an electrode material that complements or enhances thermonuclear fusion during operation of the plasma confinement system. In an exemplary embodiment, the electrode material is deuterated and / or a material selected from the group consisting of Ti, Zr, Sc, Mg, V, or 6 Li (e.g., TiD2, 6The metal hydride may be a metal hydride, such as a tritide containing one or more of the aforementioned metals (e.g., LiD, etc.), or any alloy formed by any combination of one or more of the aforementioned metals. The metal hydride may decompose to provide hydrogen fuel gas (e.g., H2, D2, T2) when exposed to the operating temperature of the plasma confinement system (e.g., during application of a Z-pin discharge current to generate a plasma arc) and may provide free neutrons upon ion bombardment (e.g., deuterium and / or tritium) and / or free tritium atoms upon neutron bombardment.

[0089] In some embodiments, method 400, or portions thereof, may be implemented as executable instructions stored in a non-transitory memory of a computing device, such as a controller communicatively coupled to the plasma confinement system. Furthermore, in certain embodiments, additional or alternative sequences of steps may be implemented as executable instructions on such a computing device, and individual steps discussed with reference to method 400 may be added, removed, substituted, modified, or replaced.

[0090] At block 402, the method 400 may include evaporating a metal precursor layer onto the bulk material. In some embodiments, the bulk material may include a metal such as copper (Cu), tungsten (W), or Ti. In additional or alternative embodiments, the metal precursor layer may include a metal such as Ti, Zr, Sc, Mg, V, 6 The metal precursor layer may include one or more of Li, Li, or any alloy formed by any combination of one or more of the aforementioned metals. The metal precursor layer may be formed to less than a predetermined thickness or within a threshold range of a predetermined thickness. In an exemplary embodiment, the predetermined thickness may be on the order of a millimeter (e.g., on the order of a few hundred microns).

[0091] In an exemplary embodiment, the bulk material may form a shaft (e.g., a substantially cylindrical body) that terminates in a nosecone. In one example, the metal precursor layer may be evaporated only on the nosecone. To confine the metal precursor layer to cover only a portion of the bulk material (e.g., the nosecone), the bulk material may be masked such that the metal precursor layer may be evaporated only on the exposed, unmasked portion of the bulk material (e.g., the nosecone).

[0092] At block 404, the method 400 may include loading the metal precursor layer with deuterium and / or tritium generated via an ion beam source to form an electrode for the plasma confinement system. In an exemplary embodiment, the ion beam source may be external to and separate from the plasma confinement system. In other embodiments, the metal precursor layer may be loaded during operation of the plasma confinement system (e.g., via a plasma arc generated by application of a Z-pinch discharge current), and thus loading may additionally or alternatively occur after block 406 (see below), although the external ion beam source may load the deuterium and / or tritium at a significantly faster rate. For example, the external ion beam source may be a 10-100 kV deuterium ion source that may optionally be loaded with tritium ions. In other examples, tritium ions may be loaded via an additional external ion beam source. Examples of ion implantation depths in Ti (which may form the metal precursor layer in some examples) are H, D, T, 3 He, and 4 The graph for He ions is shown in FIG.

[0093] In an exemplary embodiment, deuterium and / or tritium may be loaded into the metal precursor layer to form an electrode material layer (e.g., a metal layer loaded with deuterium and / or tritium) on the bulk material. n Metal hydrides (e.g., MD n and / or MT nwhere n is the molar ratio of hydrogen atoms (e.g., any one of a variety of hydrogens including D and / or T) to metal ions M in the solid phase. For example, n can be 2, such as in TiH2 (e.g., TiD2 and / or TiT2). Continuing with the TiH2 example, Ti in the electrode material layer can be 0.01 to 0.01. Ti For a given mass of some Ti atoms, N Ti can be given as follows:

number

[0094] At block 406, the method 400 may include positioning the electrode to be exposed to a plasma confinement chamber of a plasma confinement system. In an exemplary embodiment, the plasma confinement chamber may be divided into an acceleration region and an assembly region, and the electrode may be positioned to be exposed to each of the acceleration region and the assembly region. As one example, the electrode may be an inner electrode coaxial with the plasma confinement chamber so as to extend through the acceleration region such that an end of the inner electrode may be exposed to the assembly region. As an additional or alternative example, the electrode may be an outer electrode that at least partially circumferentially surrounds the inner electrode and at least partially defines an outer boundary of each of the acceleration region and the assembly region. As another example, the electrode may be an intermediate electrode that at least partially circumferentially surrounds the inner electrode and at least partially defines an outer boundary of the acceleration region that extends such that an end of the intermediate electrode may be exposed to the assembly region.

[0095] At block 408, the method 400 may include generating a request to initialize the plasma confinement system, according to which an initialization phase of the plasma confinement system may be initiated. In an exemplary embodiment, the request may be generated in response to receiving a user input from an operator of the plasma confinement system, for example. For example, the initialization of the plasma confinement system may be triggered or otherwise initiated via an operator interacting with a user interface, for example, a push button switch, toggle switch, or other mechanical actuator, keyboard, touch screen, cursor input, etc.

[0096] At block 410, the method 400 may include initiating a plasma arc generation phase of the plasma confinement system, for example after an initialization phase. Specifically, in an exemplary embodiment, the plasma arc generation phase may be initiated by powering at least the plasma confinement system (e.g., one or more power sources may provide power to various components utilized during the plasma arc generation phase) and providing a fuel gas for forming a plasma in the plasma confinement chamber by increasing one or more valve openings. In an exemplary embodiment, the fuel gas may include one or more of D2 or T2.

[0097] At block 412, the method 400 may include generating a plasma arc in the plasma confinement chamber, for example, during the plasma arc generation stage. In an exemplary embodiment, a Z-pinch discharge current may be applied at a repetition rate between an electrode including an electrode material layer and another electrode to generate a plasma arc. Thus, during operation of the plasma confinement system, the electrode may function as either a cathode in some embodiments or an anode in other embodiments. The Z-pinch discharge current may be stabilized by a shear ion velocity flow that is generated and maintained via an applied residual current. As a result of the plasma arc generation, the electrode may be heated and / or the electrode may be bombarded with deuterium, tritium, and free neutrons (e.g., resulting from thermonuclear fusion in the plasma arc). The amount of heat generated by the electrode and / or ion / neutron bombardment may depend on the position of the electrode relative to the plasma arc (e.g., whether the plasma arc is directly interacting with the electrode).

[0098] In an exemplary embodiment, a metal hydride included in the electrode material layer may decompose (e.g., via equation (2)) into a metal and a fuel gas when the electrode is heated to a decomposition temperature during operation of the plasma confinement system to generate a plasma arc. n An example of isothermal pressure for the decomposition of a species is provided in FIG.

[0099] In additional or alternative embodiments, the metal hydride included in the electrode material layer may release or eject free neutrons upon ion bombardment of the metal hydride. Specifically, deuterium and / or tritium from the plasma arc may interact with hydrogen in the metal hydride via a thermonuclear fusion reaction (e.g., reaction (1)) to produce 4 He and free neutrons may be generated.

[0100] Metal hydrides 6 In additional or alternative embodiments including Li, the metal hydride included in the electrode material layer may release or eject free tritium atoms upon neutron bombardment of the metal hydride. Specifically, free neutrons from the plasma arc may react with the metal hydride (e.g., via reaction (3)) to form a6 Li interacts with tritium, as well as deuterium and 4 He may be generated.

[0101] In certain embodiments, the metal hydride may be replenished after its depletion after a period of use of the plasma confinement system, for example, the period of use may be 1000 hours.

[0102] 6, a plot 500 of ion implantation depth in Ti as a function of ion energy is shown for various ion examples. The Ti may be included, for example, in a bulk material or in a relatively thin layer or film disposed on the bulk material. In plot 500, the abscissa represents ion energy (keV) and the ordinate represents ion implantation depth (μm). H, D, T, 3 He, and 4 The ion implantation depths of He ions are plotted in curves 502, 504, 506, 508, and 510, respectively. As shown, for a given ion energy plotted in plot 500, the ion implantation depths are: 3 He, 4 The energy of the ion beam may increase in the sequential order of He, H, D, and T. Thus, for a given ion implantation depth, the higher energy ion beam will have more H, 3 He, and 4 In comparison to the ion beams used for He, they can be used to implant D and T into Ti.

[0103] Referring now to FIG. 7, titanium hydride (TiH n 6 shows a plot 600 of isothermal pressure as a function of H:Ti atomic ratio, n, for various examples of TiH 2 O 3 . In plot 600, the abscissa represents the H:Ti atomic ratio on a linear scale and the ordinate represents the isothermal pressure (Torr) on a logarithmic scale. The isothermal pressure values ​​are plotted against the H:Ti atomic ratio for various fixed temperatures including 200° C. (point 602), 225° C. (point 604), 250° C. (point 606), 275° C. (point 608), and 300° C. (point 610). n6 is a plot of the steady state decomposition of TiH. As shown, for a given H:Ti atomic ratio in plot 600, the isothermal pressure may increase with increasing temperature. Furthermore, at a given temperature, the isothermal pressure may trend upward as the H:Ti atomic ratio increases. Thus, higher temperatures and higher H:Ti atomic ratios may increase the decomposition of TiH n Higher pressures can be generated as a result of the decomposition of H into Ti and H2.

[0104] 8A and 8B, respectively, show schematic cross-sectional views of an electrode 702 (also referred to herein as an electrode body 702 or an in situ regenerable electrode 702) in a plasma confinement chamber 706 of a plasma confinement system 700 for a thermonuclear fusion reactor 701. Specifically, the schematic cross-sectional view of FIG. 8A shows the electrode 702 and plasma confinement chamber 706 during operation of the thermonuclear fusion reactor 701, and the schematic cross-sectional view of FIG. 8B shows the electrode 702 and plasma confinement chamber 706 before and after operation of the thermonuclear fusion reactor 701. During operation of the thermonuclear fusion reactor 701, a plasma arc 708 may be generated and then confined, compressed, and maintained by an axially symmetric magnetic field. The axially symmetric magnetic field may be stabilized by a shear ion velocity flow driven by an electric discharge between the electrode 702 and at least one additional electrode interfacing with the plasma confinement chamber 706.

[0105] The electrode 702 may be referred to as an in situ regenerable electrode 702 in that the electrode 702 may include a protective film 736 (also referred to herein as a meniscus 736) of liquid metal 718 that flows continuously (e.g., without interruption or significant delay) and may be ablated from the outer surface 704a of the electrode 702 upon interaction with a plasma arc 708 generated during operation of the thermonuclear fusion reactor 701. Because the portion of the electrode 702 that interacts with the plasma arc 708 may be continuously replenished with the flowing liquid metal 718, erosion of the outer surface 704a (and thereby erosion of the entire electrode 702) during operation of the thermonuclear fusion reactor 701 may be reduced or completely eliminated.

[0106] Although the electrode 702 is described below in the context of the plasma confinement chamber 706, the electrode 702 may be positioned in any of the plasma confinement systems described above as a replacement for the electrodes therein. As one example, the electrode 702 may replace the inner electrode 302 included in the plasma confinement system 300 described in detail above with reference to Figures 1 and 3A-3F. As another example, the electrode 702 may replace the inner electrode 660 of the plasma confinement system 900 described in detail above with reference to Figure 4. Furthermore, only a portion of the plasma confinement system 700 (and thereby the thermonuclear fusion reactor 701) is shown in Figures 8A and 8B, and other components (e.g., additional electrodes, power supplies, insulators, etc.) may be added, removed, replaced, modified, or replaced, such as one or more components from the plasma confinement system 300 and / or the plasma confinement system 900.

[0107] A set of Cartesian coordinate axes 752 are shown in Figures 8A and 8B to contextualize the positions of the various components of the thermonuclear fusion reactor 701 and to compare between the schematic cross-sectional views of Figures 8A and 8B. Specifically, mutually perpendicular x-, y-, and z-axes are provided, with the x- and y-axes defining the plane of each of the schematic cross-sectional views of Figures 8A and 8B and the z-axis being perpendicular thereto. In some embodiments, the direction of gravity may be parallel to and coincident with any direction in the plane of the schematic cross-sectional views of Figures 8A and 8B. In one example, as discussed in the examples described below, the direction of gravity may be parallel to and coincident with the positive direction of the x-axis. In additional or alternative embodiments, the direction of gravity may be in the plane defined by the y- and z-axes (e.g., parallel to and coincident with the negative direction of the y-axis).

[0108] In an exemplary embodiment, the electrode 702 may be formed in a substantially cylindrical shape with a tapered rounded base or nose cone 704. Additionally or alternatively, the electrode 702 may be elongated along the x-axis such that the length of the electrode 702 along the x-axis is longer than the length of the electrode 702 along the y-axis and z-axis.

[0109] In an exemplary embodiment, the electrode 702 may be formed from a relatively high purity material, for example, to prevent the formation of (unexpected) activation products during neutron bombardment. Additionally or alternatively, the electrode 702 (e.g., its nose cone 704) may be cast or additively fabricated from a material selected for its relatively high resistance to neutron damage, such as silicon carbide. In some embodiments, the electrode 702 may include one or more of a metal (e.g., Cu and / or W), graphite, or a semiconductor (e.g., silicon carbide).

[0110] In some embodiments, the electrode 702 may be formed as a single component including the nose cone 704. In other embodiments, the nose cone 704 may be removably fastened or fixedly attached to another portion / surface of the electrode 702. Thus, in some examples, one or more fasteners or other locking structures may be provided to removably secure the nose cone 704 in place. In other examples, the nose cone 704 may be welded or otherwise adhered (e.g., with an adhesive) in place. In additional or alternative embodiments, the nose cone 704 may be electrically coupled to another portion / surface of the electrode 702 via wire / wiring or by forming the components of the electrode 702 (including the nose cone 704) from one or more conductive materials that transfer electrical current between the components when the components are placed in physical contact with one another.

[0111] The electrode 702 may be at least partially enclosed or otherwise contained within the plasma confinement chamber 706. For example, a majority of the electrode 702 may be completely surrounded by the plasma confinement chamber 706, with one end of the electrode 702 (not shown in FIGS. 8A and 8B ) extending from the plasma confinement chamber 706 in the negative x-axis direction and / or forming one wall of the plasma confinement chamber 706.

[0112] During operation of the thermonuclear fusion reactor 701, a plasma arc 708 may be generated by applying a discharge current between the electrode 702 and at least one additional electrode (not shown in FIGS. 8A and 8B ). As a result of the axially symmetric magnetic field generated by the discharge current, the plasma arc 708 may be confined and compressed to flow toward the electrode 702 along the central axis 710 (e.g., parallel to the x-axis, with the plasma arc 708 flowing in its negative direction), as indicated by arrow 712.

[0113] The electrode 702 may be positioned such that a central axis of the substantially cylindrical shape coincides with a central axis 710 of the plasma arc 708. Thus, an outer surface 704a of the electrode 702, more specifically, the nosecone 704, may intersect with the central axis 710 of the plasma arc 708 during its initiation and confinement. In this manner, the plasma confinement chamber 706 may completely surround the exterior of the nosecone 704.

[0114] The electrode 702 may include an internal reservoir 714 enclosed or otherwise contained therein. In an exemplary embodiment, the internal reservoir 714 may occupy a core region of the electrode 702, for example, extending along and radially symmetric about its central axis. As described below, the electrode 702 may include multiple channels including a first portion for flowing liquid metal 718 to the internal reservoir 714, a second portion for flowing inert gas 726 to the internal reservoir 714, a third portion for flowing liquid metal 718 from the internal reservoir 714 to the exterior of the nose cone 704, and a fourth portion for flowing heat exchange fluid 741 to maintain or regulate (e.g., increase or decrease depending on one mode of operation of the plasma confinement system 700 or one or more conditions) the temperature of the electrode 702 and / or the temperature of the liquid metal 718.

[0115] The internal reservoir 714 may contain at least a portion of a liquid metal 718, which is supplied to the internal reservoir 714 via a liquid metal supply channel 716 (e.g., formed as a conduit or piping), as indicated by arrow 734a. Specifically, the liquid metal supply channel 716 may fluidly connect the internal reservoir 714 to a liquid metal source 720 (e.g., a pressurized storage tank), which is located outside the plasma confinement chamber 706. The liquid metal source 720 may include at least a portion of the liquid metal 718 (see arrow 734a), which may be controllably supplied to the internal reservoir 714 via actuation of a valve 722 (not shown in FIGS. 8A and 8B , but controlled, for example, by a corresponding regulator). 8A, the valve 722 is in an open position that allows the liquid metal 718 to flow substantially freely into the internal reservoir 714, however, the valve 722 may also be placed in a closed position (see FIG. 8B) that prevents the liquid metal 718 from flowing from the liquid metal source 720 to the internal reservoir 714. In some embodiments, the valve 722 may be continuously variable such that the valve 722 can have a range of partially open positions that allow greater flow than the closed position and less flow than the open position.

[0116] In an exemplary embodiment, the liquid metal 718 may include any metal that may exist in a liquid state under the operating temperature of the thermonuclear fusion reactor 701. Additionally or alternatively, the liquid metal 718 may be selected for a relatively high resistance to neutron damage (in certain embodiments, the liquid metal 718 may be more resistant to neutron damage than the composition of the electrodes 702). Furthermore, radiation losses may scale with the amount and atomic number of contaminants. Thus, the liquid metal 718 may include, for example, lithium (Li). In additional or alternative examples, additives may be included to modify, for example, viscosity, surface tension, etc. In certain examples, additives may be selected for reduced toxicity and flammability. As an example, the liquid metal 718 may include, for example, bismuth (Bi) and / or lead (Pb) in the form of Li compounds / mixtures / alloys that include Bi and / or Pb. In other embodiments, liquid lithium hydride may populate some or all of the liquid metal 718 for a similar purpose, for example to form a protective film 736 on the exterior surface 704a.

[0117] The internal reservoir 714 may further include at least a portion of an inert gas 726, which is supplied to the internal reservoir 714 via an inert gas supply channel 724 (e.g., formed as a conduit or piping). Specifically, the inert gas supply channel 724 may fluidly connect the internal reservoir 714 to an inert gas source 728 (e.g., a pressurized storage tank), which is located outside the plasma confinement chamber 706. The inert gas 726 is directed in the direction of flow of the inert gas 726 as indicated by the arrows in FIG. 8A when the inert gas 726 is supplied to the internal reservoir 714 during operation of the thermonuclear fusion reactor 701. The inert gas source 728 may contain any remaining portion of the inert gas 726 (e.g., any remaining inert gas 726 excluding the portion contained within the inert gas source 728), which may be controllably supplied to the internal reservoir 714 via actuation of the valve 730 (e.g., controlled by a corresponding regulator, not shown in FIGS. 8A and 8B ). In FIG. 8A , the valve 730 is in an open position allowing the inert gas 726 to flow substantially freely into the internal reservoir 714, but the valve 730 is also disposed in a closed position (see FIG. 8B ) to prevent the inert gas 726 from flowing from the inert gas source 728 to the internal reservoir 714. In some embodiments, the valve 730 may be continuously variable such that the valve 730 may have a range of partially open positions that allow greater flow than the closed position and less flow than the open position.

[0118] In an exemplary embodiment, the inert gas 726 may include any gas that does not significantly react with or otherwise decompose the liquid metal 718 and the electrode 702. For example, the inert gas 726 may include helium (He). In additional or alternative examples, the inert gas 726 may include one or more noble gases (neon (Ne), argon (Ar), krypton (Kr), xenon (Xe), radon (Rn), etc.).

[0119] During operation of the thermonuclear fusion reactor 701, the liquid metal 718 in the internal reservoir 714 may be maintained at, above, or within a threshold range of a liquid metal level 754, which is preselected to maintain a liquid metal flow rate for the formation and maintenance of the protective film 736. Thus, in some embodiments, the liquid metal level 754 may be adjusted to maintain the liquid metal flow rate. Additionally or alternatively, the liquid metal level 754 may be adjusted in response to a liquid metal level 758 corresponding to the amount of liquid metal 718 remaining in the liquid metal source 720 (e.g., the liquid metal level 754 may be gradually decreased in response to a gradually decreasing liquid metal level 758). Sensors (not shown in FIGS. 8A and 8B ) positioned in the internal reservoir 714 and the liquid metal source 720 may monitor the liquid metal levels 754 and 758, respectively.

[0120] The electrode 702 may include a number of internal liquid flow channels 732 fluidly connecting the internal reservoir 714 to an exterior of the nosecone 704. Each of the plurality of internal liquid flow channels 732 may include a main liquid flow channel 732a fluidly connected to and extending from the internal reservoir 714 and a number of liquid flow capillaries 732b fluidly connecting the main liquid flow channel 732a to the exterior of the nosecone 704.

[0121] In an exemplary embodiment, the central axis of the electrode 702 may be coaxial with the direction of gravity, which coincides with the positive direction of the x-axis. Thus, the nose cone 704 may be positioned below the internal reservoir 714 with respect to the direction of gravity. Furthermore, upon extending from the internal reservoir 714, each of the plurality of internal liquid flow channels 732 (e.g., its main liquid flow channel 732a) may be initially oriented upward and oriented opposite the nose cone 704. After being oriented upward, each of the plurality of internal liquid flow channels 732 (e.g., its main liquid flow channel 732a) may arch downward and toward the nose cone 704. In this manner, the combined force of the amount of liquid metal 718 provided to the internal reservoir 714 (corresponding to the liquid metal level 754) and the inert gas pressure within the internal reservoir 714 may overcome gravity to flow the liquid metal 718 through the initial upward orientation of the plurality of internal liquid flow channels 732, after which gravity may assist in increasing the liquid metal flow rate.

[0122] At least a portion of the liquid metal 718 may be provided to the exterior surface 704a from the internal reservoir 714 and along the plurality of interior liquid flow channels 732. Specifically, for each of the plurality of interior liquid flow channels 732, the liquid metal 718 may flow along a main liquid flow channel 732a, as indicated by arrow 734b, into a plurality of liquid flow capillaries 732b, as indicated by arrow 734c, and along a plurality of liquid flow capillaries to the exterior surface 704a. Although multiple liquid flow capillaries 732b are shown in Figures 8A and 8B as being fluidly connected to the outer surface 704a at the nose cone 704 and on either side of the central axis 710 of the plasma arc 708 relative to the y-axis, in other embodiments, at least a portion of the multiple liquid flow capillaries 732b may be fluidly connected to the outer surface 704a at the nose cone 704 so as to intersect the central axis 710, and / or at least a portion of the multiple liquid flow capillaries 732b may be completely fluidly connected to other portions of the outer surface 704a away from the nose cone 704.

[0123] Upon flowing to the exterior surface 704a, at least a portion of the liquid metal 718 may form a protective film 736 between the exterior surface 704a and the exterior of the nose cone 704. The protective film 736 may be held (e.g., secured, adhered, or otherwise held) on the exterior surface 704a via capillary action induced by at least a plurality of liquid flow capillaries 732b. The protective film 736 held on the nose cone 704 and substantially symmetric about the central axis of the electrode 702 may be positioned to directly interact with the plasma arc 708 during operation of the thermonuclear fusion reactor 701 (i.e., the protective film 736 may be positioned such that the plasma arc 708 physically interacts with the protective film 736 without the presence of any intervening components or volumes).

[0124] In this manner, a portion of the liquid metal 718 may be delivered (e.g., from a liquid metal source 720) to the internal reservoir 714 and along a plurality of internal liquid flow channels 732 to the exterior surface 704a. The remaining portion of the liquid metal 718 (e.g., any remaining liquid metal 718 other than the portion contained within the electrode body 702 and delivered to the exterior surface 704a) may form a protective film 736 on the exterior surface 704a.

[0125] During operation of the thermonuclear fusion reactor 701, portions of the protective film 736 may be ablated from the exterior surface 704a at a liquid metal ablation rate through interaction with the plasma arc 708 and the high discharge current that sustains the plasma arc 708. The portions of the protective film 736 ablated from the exterior surface 704a may be replenished continuously (e.g., without interruption or appreciable delay) by liquid metal 718 flowing from the internal reservoir 714 to the exterior surface 704a at a liquid metal flow rate.

[0126] In embodiments where the direction of gravity is not parallel to the positive x-axis, the protective film 736 may extend at least partially below the outer surface 704a and below the nosecone 704 along the negative x-axis. In such embodiments, various structures may be provided on the electrode 702 or within the plasma confinement system 700 to prevent the flowing liquid metal 718 from interfering with the operation of the plasma confinement system 700. For example, ports / openings (e.g., one or more fuel gas supply channels 742) along the outer surface 704a may extend parallel to a plane defined by the y-axis and z-axis from the outer surface 704a, and / or a drain / trough may be provided at the base of the electrode 702 opposite the nosecone 704 relative to the x-axis to collect excess liquid metal 718. In additional or alternative embodiments where the direction of gravity is not parallel to the positive x-axis, the protective film 736 may be asymmetric about the central axis 710 of the plasma arc 708. However, in any of the aforementioned embodiments, the protective film 736 may still intersect the central axis 710 of the plasma arc 708 during operation of the plasma confinement system 700 such that the protective film 736 is positioned between the plasma arc 708 and the outer surface 704a.

[0127] The electrode 702 may include one or more heat exchange fluid flow channels 740 that include a heat exchange fluid 741. In an exemplary embodiment, the heat exchange fluid 741 may maintain the temperature of the liquid metal 718 (e.g., the protective film 736 that forms a portion of the liquid metal 718) and / or a portion or substantially all of the electrode 702. In some embodiments, multiple heat exchange fluid flow channels 740 may be included in the electrode 702, e.g., each heat exchange fluid flow channel 740 maintains the temperature of a different portion or component of the electrode 702. In other embodiments, only one heat exchange fluid flow channel 740 may be included in the electrode 702, e.g., coiled around its central axis and extending along a portion or substantially the entire length of the electrode 702 along the x-axis. In an exemplary embodiment, the one or more heat exchange fluid flow channels 740 may be separated and fluidly isolated from the plasma confinement chamber 706 and the internal reservoir 714, and from the multiple internal liquid flow channels 732 therebetween. In additional or alternative embodiments, an internal heating element / device 743 (e.g., a mineral insulated cable interleaved with one or more heat exchange fluid flow channels 740, such as an internal heating coil, as shown in FIGS. 8A and 8B, although other configurations are possible) is thermally coupled to (e.g., positioned internally within) the internal reservoir 714 to dump heat, thereby providing greater control over temperature maintenance / regulation (e.g., heating and cooling functions may be split between the internal heating element / device 743 and one or more heat exchange fluid flow channels 740). In additional or alternative embodiments, an additional heating element / device (not shown in FIGS. 8A and 8B) may be thermally coupled to the liquid metal source 720. In such embodiments, operation of the additional heating element / device may adjust the temperature of the liquid metal 718 in the liquid metal source 720, such as to melt / liquefy the liquid metal 718, or otherwise adjust the liquid metal flow rate before the liquid metal 718 is channeled to the internal reservoir 714.

[0128] In an exemplary embodiment, the heat exchange fluid 741 may include one or more of a liquid metal (e.g., liquid lithium or mixtures thereof), a molten salt (e.g., as a dielectric fluid), water, or an inert gas. Thus, in certain embodiments, one or both of the liquid metal 718 and the heat exchange fluid 741 may be liquid lithium.

[0129] During operation of the thermonuclear fusion reactor 701, the plasma confinement chamber 706 may contain at least a portion of a fuel gas 744, which is supplied to the plasma confinement chamber 706 via one or more fuel gas supply channels 742 (e.g., formed as one or more conduits or piping). Specifically, the one or more fuel gas supply channels 742 may fluidly connect the plasma confinement chamber 706 to one or more fuel gas sources 746 (e.g., one or more pressurized storage tanks), respectively, which are located outside the plasma confinement chamber 706. The fuel gas 744 is directed in the flow direction of the fuel gas 744 when the fuel gas 744 is supplied to the plasma confinement chamber 706 during operation of the thermonuclear fusion reactor 701, as indicated by the arrows in FIG. 8A. The one or more fuel gas sources 746 may include any remaining portion of the fuel gas 744 (e.g., any remaining fuel gas 744 excluding the portion contained within the one or more fuel gas sources 746), which may be controllably supplied to the plasma confinement chamber 706 via actuation of one or more valves 748 (e.g., each controlled by one or more corresponding controllers, not shown in FIGS. 8A and 8B). Each of the one or more valves 748 is in an open position, as shown in FIG. 8A, that allows the fuel gas 744 to flow substantially freely into the plasma confinement chamber 706, while each of the one or more valves 748 may be independently disposed in a closed position (see FIG. 8B) to prevent the fuel gas 744 from flowing from the one or more fuel gas sources 746 into the plasma confinement chamber 706. In some embodiments, each of the one or more valves 748 may be continuously variable such that each of the one or more valves 748 may have a range of partially open positions that allow greater flow than the closed position and less flow than the open position.

[0130] In an exemplary embodiment, fuel gas 744 may be ionized to form a plasma and may include any gas containing nuclei that may undergo thermonuclear fusion under practical conditions (e.g., conditions achievable in a laboratory or power plant setting). For example, fuel gas 744 may include one or more of D2 or T2 (e.g., capable of being ionized to form nucleons that may undergo thermonuclear fusion via reaction (1)).

[0131] The liquid metal flow rate may be preselected and / or dynamically adjusted to maintain a predetermined thickness 738 of the protective film 736, for example, in response to its ablation. For example, the liquid metal flow rate may deviate from the liquid metal ablation rate during operation of the thermonuclear fusion reactor 701, e.g., the liquid metal flow rate may decrease as a result of the expansion of the electrode 702 due to cumulative neutron damage, and the liquid metal ablation rate may decrease / increase in response to a corresponding decrease / increase in the discharge current or intensity of the plasma arc 708, etc. Thus, to maintain the predetermined thickness 738, the liquid metal flow rate and its changes may be preselected and / or dynamically adjusted to match the liquid metal ablation rate. In some embodiments, the liquid metal flow rate may be preselected as a single value, which may be dynamically adjusted during operation of the thermonuclear fusion reactor 701. In other embodiments, the liquid metal flow rate may be preselected as a series of values ​​following from the expected operation of the thermonuclear fusion reactor 701.

[0132] In an exemplary embodiment, the liquid metal flow rate may be adjusted in response to deviations from the liquid metal ablation rate by more than a threshold magnitude. Additionally or alternatively, the inert gas pressure in the internal reservoir 714 may be adjusted in response to the liquid metal flow rate deviating from the liquid metal ablation rate greater than a threshold magnitude, where a corresponding decrease / increase in the inert gas pressure decreases / increases the liquid metal flow rate. In certain embodiments, the inert gas pressure may tend to increase (e.g., increase on average) over the lifetime of the thermonuclear fusion reactor 701, overcoming increased flow resistance in the multiple internal liquid flow channels 732 as the electrode body 702 expands due to cumulative neutron damage.

[0133] As an example, in response to the liquid metal flow rate being lower than the liquid metal ablation rate by a threshold magnitude, the liquid metal flow rate may be increased by one or more of: adjusting valve 722 from a partially open or closed position toward an open position to provide a greater amount of liquid metal 718 from liquid metal source 720, adjusting valve 730 from a partially open or closed position toward an open position to provide a greater amount of inert gas 726 from inert gas source 728, increasing the flow rate of heat exchange fluid in one or more heat exchange fluid flow channels 740, or increasing heat from an internal heating element / device 743. Additionally or alternatively, in response to the liquid metal flow rate being lower than the liquid metal ablation rate by a threshold magnitude, the liquid metal ablation rate may be decreased by one or more of: adjusting at least one of one or more valves 748 from an open or partially open position toward a closed position, or decreasing the discharge current.

[0134] As another example, in response to the liquid metal flow rate being higher than the liquid metal ablation rate by a threshold magnitude, the liquid metal flow rate may be decreased by one or more of: adjusting the valve 722 from an open or partially open position toward a closed position to provide a lesser amount of liquid metal 718 from the liquid metal source 720, adjusting the valve 730 from an open or partially open position toward a closed position to provide a lesser amount of inert gas 726 from the inert gas source 728, decreasing the flow rate of heat exchange fluid in one or more heat exchange fluid flow channels 740, or decreasing heat from the internal heating element / device 743. Additionally or alternatively, in response to the liquid metal flow rate being higher than the liquid metal ablation rate by a threshold magnitude, the liquid metal ablation rate may be increased by one or more of: adjusting at least one of the one or more valves 748 from a partially open or closed position toward an open position, or increasing the discharge current.

[0135] In some embodiments, a drain or trough (not shown in FIGS. 8A and 8B) may be fluidly connected to the plasma confinement chamber 706. With the ablation of the liquid metal 718 from the exterior surface 704a, at least a portion of the ablated liquid metal 718 may fall or flow into the drain or trough.

[0136] 8B, each of valves 722, 730, and 748 may be in a closed position. Specifically, valve 722 may be in a closed position to prevent liquid metal 718 from flowing from liquid metal source 720 to internal reservoir 714, valve 730 may be in a closed position to prevent inert gas 726 from flowing from inert gas source 728 to internal reservoir 714, and each of one or more valves 748 may be in a closed position to respectively prevent fuel gas 744 from flowing from each of one or more fuel gas sources 746 to plasma confinement chamber 706.

[0137] In some embodiments, liquid metal 718 may not be able to flow from the interior reservoir 714 to the exterior surface 704a when the liquid metal level 754 reaches or falls below a threshold level 756. Thus, and as shown in FIG. 8A, the liquid metal level 754 may be maintained above the threshold level 756 during operation of the thermonuclear fusion reactor 701. However, as shown in FIG. 8B, in response to the liquid metal level 754 reaching or falling below the threshold level 756, the thermonuclear fusion reactor 701 may cease operation and the protective film 736 may not be formed.

[0138] The thermonuclear fusion reactor 701 may include a controller or other computing device 750, which may include a non-transitory memory in which executable instructions may be stored. The executable instructions may be executed by one or more processors of the controller 750 to perform various functions of the thermonuclear fusion reactor 701. Thus, the executable instructions may include various routines for operation, maintenance, and testing of the thermonuclear fusion reactor 701. The controller 750 may further include a user interface through which an operator of the thermonuclear fusion reactor 701 may enter commands or otherwise modify the operation of the thermonuclear fusion reactor 701. The user interface may include various components for facilitating operator use of the thermonuclear fusion reactor 701 and for receiving operator input (e.g., a request to generate plasma for thermonuclear fusion), such as one or more displays, input devices (e.g., keyboards, touch screens, computer mice, pressable buttons, mechanical switches, or other press actuators, etc.), lights, etc. The controller 750 may be communicatively coupled to various components (e.g., valves, power sources, etc.) of the thermonuclear fusion reactor 701 to command its operation and use (for clarity, wired and / or wireless communication paths between the controller 750 and the various components are omitted in FIGS. 8A and 8B ). For example, dynamic adjustments to the liquid metal flow rate may be based on one or more inputs (e.g., liquid metal ablation rate, etc.) received at the controller 750, which may be correlated with each other and / or with the liquid metal flow rate (e.g., via one or more neural networks stored in non-transitory memory). Based on the correlation, the controller 750 may output adjustments to the liquid metal flow rate, which may be performed via operation of the various components of the thermonuclear fusion reactor 701 (e.g., to adjust the amount of liquid metal 718 provided to the internal reservoir 714, to adjust the amount of inert gas 726 provided to the internal reservoir 714, to adjust the heat exchange fluid flow rate, to adjust heat from the internal heating element / device 743, etc.).

[0139] The liquid metal source 720, the inert gas source 728, and the fuel gas source 746 may be located along with the various valves (e.g., valves 722, 730, and 748), control systems (e.g., controller 750), and other sensitive or complex components at a sufficient distance from the plasma confinement chamber 706 to mitigate degradation of the components due to high neutron flux during thermonuclear fusion. As such, long tubing (e.g., supply channels 716, 724, and 742), wires, cables, and other coupling or communication lines may extend between the plasma confinement chamber 706 (and the electrode 702 at least partially enclosed therein) and the various sensitive and complex components described above.

[0140] As described herein above, the electrode 702 may be formed in a substantially cylindrical shape with a tapered rounded nose cone 704. The substantially cylindrical shape (including the nose cone 704) may be radially symmetrical with respect to the x-axis, with the cross-sections of Figures 8A and 8B taken at the widest part of the substantially cylindrical shape along the y-axis. Additionally, the components shown in the cross-sections of Figures 8A and 8B may be replicated about the x-axis such that they are radially symmetrically distributed in one or more planes that include the x-axis. For example, the multiple internal liquid flow channels 732 and / or the one or more fuel gas supply channels 742 may be regularly spaced about the x-axis (e.g., at angles of 60°, 90°, etc. relative to one another).

[0141] 9A and 9B, a block diagram of a method 800 for operating a plasma confinement system of a thermonuclear fusion reactor, such as any of the plasma confinement systems described in detail above with reference to FIGS. 1-4, 8A, and 8B, is shown. In an exemplary embodiment, the plasma confinement system may include an in-situ regenerable electrode that includes a protective film of flowing liquid metal that may be ablated from an outer surface of the electrode upon interaction with a plasma arc generated by and confined within the plasma confinement system. Specifically, as described below, the protective film may be replenished continuously (e.g., without interruption or significant delay) in response to ablation such that high discharge erosion of the outer surface of the electrode resulting from plasma arc interaction may be mitigated or completely eliminated.

[0142] In some embodiments, method 800, or portions thereof, may be implemented as executable instructions stored in a non-transitory memory of a computing device, such as a controller communicatively coupled to the plasma confinement system. Furthermore, in certain embodiments, additional or alternative sequences of steps may be implemented as executable instructions on such a computing device, and individual steps discussed with reference to method 800 may be added, removed, substituted, modified, or replaced.

[0143] 9A, at block 802, the method 800 may include generating a request to initialize the plasma confinement system, according to which an initialization phase of the plasma confinement system may be initiated. In an exemplary embodiment, the request may be generated in response to receiving a user input from an operator of the plasma confinement system, for example. For example, the initialization of the plasma confinement system may be triggered or otherwise initiated via an operator interacting with a user interface, for example, a push button switch, toggle switch, or other mechanical actuator, keyboard, touch screen, cursor input, etc.

[0144] At block 804, the method 800 may include, for example, flowing liquid metal from an internal reservoir of the electrode onto an outer surface of the electrode at a liquid metal flow rate during an initialization phase. In an exemplary embodiment, when the liquid metal reaches the outer surface, it may form a protective film or meniscus between the outer surface and the plasma confinement chamber containing the electrode (e.g., at and about a central axis of the plasma confinement chamber that may interact with the electrode when a plasma arc is generated).

[0145] The liquid metal flow rate may be preselected by an operator of the plasma confinement system based on, for example, one or more operating conditions of the plasma confinement system. For example, the one or more operating conditions may include an inert gas pressure in the internal reservoir, a liquid metal level in the internal reservoir, a liquid metal temperature, an amount of fuel gas provided to the plasma confinement chamber, a magnitude of a Z-pin discharge current applied to the plasma (see block 814 below), and the like. Specifically, at block 806, liquid metal may be supplied to the internal reservoir up to the liquid metal level. For example, a first valve opening may be increased to allow liquid metal to flow from a liquid metal source into the internal reservoir. At block 808, inert gas may be supplied to the internal reservoir until the inert gas pressure is met. For example, a second valve opening may be increased to allow inert gas to flow from an inert gas source into the internal reservoir. At block 810, the liquid metal temperature may be maintained, for example, in the internal reservoir. For example, a heat exchange fluid may flow through the electrode, for example, via a flow channel that may be positioned to transfer heat to and from the liquid metal, and / or by regulating heat from an internal heating coil of the electrode, for example, that may be positioned in an internal reservoir. In some embodiments, a heat exchange fluid may flow through the electrode, and / or an internal heating coil may be heated prior to flowing the liquid metal and generating a plasma arc to preheat the electrode for use. Each of the liquid metal level, inert gas pressure, and liquid metal temperature may be preselected at the start of the plasma confinement system (e.g., according to a request to start the plasma confinement system) and / or may be dynamically adjusted during operation of the plasma confinement system. In an exemplary embodiment, the liquid metal level, inert gas pressure, and liquid metal temperature may be carefully balanced with each other to achieve and maintain a liquid metal flow rate.

[0146] At block 812, the method 800 may include initiating a plasma arc generation phase of the plasma confinement system, for example after the initialization phase. Specifically, in an exemplary embodiment, the plasma arc generation phase may be initiated by powering at least the plasma confinement system (e.g., one or more power sources may provide power to various components utilized during the plasma arc generation phase) and providing a fuel gas for forming a plasma in the plasma confinement chamber by increasing one or more third valve openings. In an exemplary embodiment, the fuel gas may include one or more of D2 or T2.

[0147] 9B, at block 814, the method 800 may include, for example, generating a plasma arc in the plasma confinement chamber during the plasma arc generation stage. In an exemplary embodiment, a Z-pinch discharge current may be applied at a repetition rate between a pair of electrodes, the pair of electrodes including an in-situ renewable electrode, to generate a plasma arc. Thus, during operation of the plasma confinement system, the in-situ renewable electrode may function as either a cathode in some embodiments or an anode in other embodiments. The plasma arc may be confined, compressed, and maintained via an axially symmetric magnetic field generated by the Z-pinch discharge current, which is stabilized by a sheared ion velocity flow created and maintained via an applied residual current. As a result of the plasma arc generation, the pair of electrodes may be heated and bombarded with deuterium, tritium, and free neutrons (e.g., resulting from thermonuclear fusion within the plasma arc). More specifically, as the Z-pinch discharge current increases, the temperature of each of the electrodes may increase, and an increased amount of deuterium, tritium, and free neutrons may bombard the electrodes. However, an in situ regenerable electrode may reduce or completely eliminate erosion of the electrode's outer surface during such bombardment by continually replenishing the electrode's outer surface.

[0148] Specifically, at block 816, the method 800 may include ablating liquid metal from an exterior surface of the electrode (e.g., not the exterior surface of the electrode itself) at a liquid metal ablation rate via the plasma arc. Specifically, in some cases, application of a Z-pinch discharge current to the electrode in addition to neutron bombardment from the plasma arc may result in ablation of liquid metal from the exterior surface of the electrode. Liquid metal may be replenished continuously (e.g., without interruption or appreciable delay) at the exterior surface from an internal reservoir.

[0149] At block 818, the method 800 may include determining whether the liquid metal level is at or below a threshold level. In an exemplary embodiment, the threshold level may be a level within the internal reservoir at which liquid metal may no longer be supplied to the exterior surface at a desired liquid metal flow rate. Thus, in some examples, the threshold level may be dynamically adjusted based on the desired operation of the plasma confinement system.

[0150] If the liquid metal level is greater than the threshold level, method 800 may proceed to block 820, where method 800 may include determining whether to adjust the repetition rate of the Z-pin discharge current according to demands generated by the plasma confinement system, for example.

[0151] If an adjustment in the repetition rate is indicated, method 800 may proceed to block 822, where method 800 may include adjusting the repetition rate of the Z-pinch discharge current. In an exemplary embodiment, the repetition rate may be adjusted based on a desired power production, e.g., as indicated in the request to adjust the repetition rate. As one example, the repetition rate may be increased in response to a request to adjust the repetition rate indicating an increase in power production. As another example, the repetition rate may be decreased in response to a request to adjust the repetition rate indicating a decrease in power production. Thus, in such an example, the request to adjust the repetition rate may be indicative of adjusting the power production (e.g., a request to adjust the power production may be generated, which may result in the repetition rate being adjusted accordingly).

[0152] Additionally, the liquid metal ablation rate may be adjusted as a result of the repetition rate being adjusted. As one example, the liquid metal ablation rate may increase as a result of the repetition rate being increased (e.g., less liquid metal may be retained on the outer surface of the electrode). As another example, the liquid metal ablation rate may decrease as a result of the repetition rate being decreased (e.g., more liquid metal may be retained on the outer surface of the electrode). Thus, in such an example, a request to adjust the repetition rate may be indicative of adjusting the power generation (e.g., a request to adjust the power generation may be generated, which may result in the repetition rate being correspondingly adjusted).

[0153] At block 824, the method 800 may include adjusting the liquid metal flow rate. As one example, the liquid metal flow rate may be adjusted in response to the adjusted repetition rate (see block 822 above). As another example, the liquid metal flow rate may be adjusted in response to the liquid metal flow rate deviating from the liquid metal ablation rate by a threshold amount (see block 826 below). The liquid metal flow rate may be non-zero before and after adjusting the liquid metal flow rate, for example, because the plasma confinement system may operate immediately before and after block 824. Thus, before the adjustment, the liquid metal flow rate may be a first non-zero value, and after the adjustment, the liquid metal flow rate may be a second non-zero value, the second non-zero value being different from the first non-zero value.

[0154] In an exemplary embodiment, adjusting the liquid metal flow rate may include adjusting one or more of a liquid metal level in the internal reservoir, an inert gas pressure in the internal reservoir, or a liquid metal temperature. As an example, increasing the liquid metal flow rate may include increasing one or more of the liquid metal level, the inert gas pressure, or the liquid metal temperature. As another example, decreasing the liquid metal flow rate may include decreasing one or more of the liquid metal level, the inert gas pressure, or the liquid metal temperature. In certain embodiments, adjusting the inert gas pressure may include increasing the inert gas pressure on average (e.g., increasing by a net amount) over the life use of the electrode, for example, in response to cumulative neutron damage that expands the electrode. In certain embodiments, the liquid metal flow rate may be adjusted in a feed-forward manner to take into account dynamic changes in the plasma confinement system detected during a previous use session, or premature discharges (e.g., after a short delay, such as 0.5 seconds) during the same use session. The method 800 may return to block 814 to continue generating a plasma arc in the plasma confinement chamber.

[0155] If no adjustment to the repetition rate is indicated (see block 820 above), the method 800 may proceed to block 826, where the method 800 may include determining whether the liquid metal flow rate has deviated from the liquid metal ablation rate by more than a threshold magnitude.

[0156] In an exemplary embodiment, the liquid metal flow rate may be matched to the liquid metal ablation rate such that the protective film or meniscus on the outer surface of the electrode may be maintained at a consistent thickness. Thus, if the liquid metal flow rate deviates from the liquid metal ablation rate by more than a threshold amount, method 800 may proceed to block 824, where method 800 may include adjusting the liquid metal flow rate (as described above).

[0157] If the liquid metal flow rate is maintained within the threshold magnitude of the liquid metal ablation rate, the method 800 may proceed to block 828, where the method 800 may include determining whether to stop the plasma arc generation, for example, according to a request generated by the plasma confinement system. If the plasma arc generation is not commanded to stop, the method 800 may return to block 814 and continue to generate the plasma arc in the plasma confinement chamber.

[0158] If it is indicated to stop the plasma arcing or if the liquid metal level is below the threshold level (see block 818 above), the method 800 may proceed to block 830, where the method 800 may include stopping the plasma arcing. Specifically, the Z-pinch discharge current may cease to be applied to the plasma, and one or more third valve openings may be reduced or completely closed to reduce or stop the supply of fuel gas to the plasma confinement chamber such that the plasma arc may become unsustainable and be stopped.

[0159] At block 832, the method 800 may include, for example, stopping the flow of liquid metal from the internal reservoir to the exterior surface of the electrode. For example, the first valve opening may be closed to stop the supply of liquid metal to the internal reservoir and thereby to the exterior surface. In some embodiments, upon stopping the flow of liquid metal, liquid metal may be removed from the internal reservoir and one or more internal channels fluidly connected thereto by purging with a gas, for example, an inert gas.

[0160] At block 834, the method 800 may include removing at least a portion of the liquid metal from the outer surface of the electrode, e.g., relative to the amount of liquid metal present during the plasma arc generation phase. In an exemplary embodiment, the liquid metal may be removed by increasing the liquid metal temperature (e.g., by increasing the flow of heat exchange fluid through the electrode and / or by increasing heat from an internal heating coil), so that the liquid metal flow rate may increase at the outer surface (even though the plasma arc is not interacting with the outer surface). Thus, after the generation of the plasma arc and cessation of the flow of liquid metal to the outer surface, the liquid metal may flow away from the outer surface and be collected in the plasma confinement chamber, e.g., in a trough, and / or exit the plasma confinement chamber and be collected, e.g., via a drain.

[0161] Following liquid metal removal, in some embodiments, a smaller amount of liquid metal may remain on the exterior surface of the electrode relative to the amount of liquid metal present on the exterior surface during operation of the plasma confinement system. In one embodiment, all or substantially all of the liquid metal is removed from the exterior surface after liquid metal removal. For example, none of the liquid metal may be visibly present (e.g., to the human eye) on the exterior surface after liquid metal removal. In additional or alternative embodiments, a small portion of the liquid metal may be present (e.g., visibly present) on the exterior surface after liquid metal removal, but not in a sufficient amount to substantially affect future operation of the plasma confinement system. In other embodiments, a portion of the liquid metal may be present on the exterior surface after liquid metal removal, for example, to protect the body of the electrode from erosion during future operation of the plasma confinement system.

[0162] Embodiments of the present disclosure can be described in view of the following passages. 1. A plasma confinement system comprising: a plurality of electrodes, each electrode of the plurality of electrodes being disposed coaxially with respect to an assembly region of the plasma confinement system and positioned so as to be exposed to the assembly region; A plasma confinement system, wherein one or more of the plurality of electrodes includes an electrode material that releases hydrogen gas above a threshold temperature. 2. Multiple electrodes a first electrode positioned to define at least a portion of an outer boundary of an assembly area; and a second electrode positioned to define one end of the assembly region. 3. The plasma confinement system described in paragraph 2, wherein the plurality of electrodes further includes a third electrode positioned at the same end of the assembly region defined by the second electrode or at an end of the assembly region opposite the end of the assembly region defined by the second electrode. 4. A plasma confinement system as described in paragraph 2 or 3, wherein the second electrode includes a nose cone exposed to the assembly region so as to intersect with a plasma arc axis coaxial with each electrode of the plurality of electrodes, the nose cone including an electrode material. 5. The plasma confinement system of any one of claims 1 to 4, wherein the electrode material comprises one or more of a metal deuteride or a metal tritide. 6. One or more of the metal deuterides or metal tritides is Ti, Zr, Sc, Mg, V, 6 Li, or Ti, Zr, Sc, Mg, V, or 6 Item 6. The plasma confinement system of item 5, further comprising one or more of any alloys formed by any combination of one or more of Li. 7. A plasma confinement system according to any one of claims 1 to 6, wherein the electrode material emits free neutrons upon ion bombardment of the electrode material. 8. A plasma confinement system as described in any one of paragraphs 1 to 7, wherein the electrode material releases free tritium atoms upon neutron bombardment of the electrode material. 9. The second electrode is a nosecone exposed to the assembly region so as to be intersected by a plasma arc axis coaxial with each electrode of the plurality of electrodes, optionally the nosecone comprising an electrode material; 9. The plasma confinement system of any one of clauses 2, 3, 5, 6, 7 or 8, comprising: a liquid metal, a portion of which forms a protective film between a surface of the nose cone and the assembly region during operation of the plasma confinement system. 10. A thermonuclear fusion reactor, comprising: a plasma confinement chamber; An inner electrode; an outer electrode at least partially surrounding the inner electrode; 1. A thermonuclear fusion reactor, wherein one or both of the inner or outer electrodes discharge a fuel gas between the inner and outer electrodes and contain a metal hydride that contributes a plasma to the thermonuclear fusion process of the thermonuclear fusion reactor. 11. The thermonuclear fusion reactor of claim 10, wherein one or both of the inner and outer electrodes include one or more valves that route additional fuel gas to the plasma confinement chamber during operation of the thermonuclear fusion reactor. 12. A thermonuclear fusion reactor according to paragraph 10 or 11, wherein the metal hydride decomposes into metal and fuel gas when heated to its decomposition temperature. 13. Metals are Ti, Zr, Sc, Mg, V, 6 Item 13. The thermonuclear fusion reactor of item 12, wherein the fuel gas comprises one or more of D2 or T2, or any alloy formed by any combination thereof. 14. A thermonuclear fusion reactor according to any one of claims 10 to 13, wherein the metal hydride emits free neutrons upon ion bombardment with deuterium and / or tritium. 15. A thermonuclear fusion reactor according to any one of claims 10 to 14, wherein the metal hydride ejects free tritium atoms upon neutron bombardment. 16. A method comprising: 1. Generating a thermonuclear fusion reaction in a thermonuclear fusion reactor, comprising: heating an electrode formed from the bulk material and the evaporated metal layer thereon, the metal layer being loaded with deuterium and / or tritium, causing the electrode to release hydrogen gas; forming a plasma in a thermonuclear fusion reactor using hydrogen gas; generating a thermonuclear fusion reaction by compressing the plasma using an electric current directed to the plasma via an electrode to generate a thermonuclear fusion reaction. 17. The method of claim 16, wherein the metal layer is evaporated onto the bulk material by masking the bulk material and evaporating the metal layer only onto the unmasked portions of the bulk material. 18. The method of claim 16 or 17, wherein the bulk material forms a shaft terminating in a nose cone, and the metal layer is evaporated onto only the nose cone. 19. The metal layer is Ti, Zr, Sc, and / or 6 19. The method according to any one of items 16 to 18, comprising Li. 20. The method according to any one of claims 16 to 19, wherein the thickness of the metal layer is less than a millimeter. 21. A plasma confinement system comprising: a plasma confinement chamber; An electrode body, a nosecone positioned to be exposed to the plasma confinement chamber; an internal reservoir fluidly connected to a liquid metal source, the liquid metal source supplying liquid metal to the internal reservoir during operation of the plasma confinement system; a plurality of internal liquid flow channels extending into a surface of the nosecone to fluidly connect the internal reservoir to the plasma confinement chamber. 22. A plasma confinement system as described in paragraph 21, wherein a first portion of the liquid metal forms a protective film between a surface of the nose cone and the plasma confinement chamber during operation of the plasma confinement system, and a remaining second portion of the liquid metal is supplied from a liquid metal source to the internal reservoir and along the multiple internal liquid flow channels toward the surface of the nose cone during operation of the plasma confinement system. 23. The plasma confinement system of claim 22, wherein the protective film is maintained at a predetermined thickness during operation of the plasma confinement system. 24. A plasma confinement system according to any one of claims 21 to 23, wherein the electrode body is formed from one or more of a metal, graphite, or a semiconductor. 25. A plasma confinement system as described in any one of clauses 21 to 24, wherein the electrode body is coaxial with the direction of gravity, and the nose cone is positioned below the internal reservoir with respect to the direction of gravity, and wherein extending from the internal reservoir, each internal liquid flow channel of the multiple internal liquid flow channels is initially oriented upwardly and opposite to the nose cone, from which each internal liquid flow channel of the multiple internal liquid flow channels arches downwardly and toward the nose cone. 26. Each internal liquid flow channel of the plurality of internal liquid flow channels comprises: a primary liquid flow channel fluidly connected to and extending from the internal reservoir; 26. The plasma confinement system of any one of claims 22 to 25, comprising: a plurality of liquid flow capillaries fluidly connecting the main liquid flow channel to the plasma confinement chamber, wherein a protective film is held on a surface of the nose cone via capillary action induced by the plurality of liquid flow capillaries. 27. A plasma confinement system as described in any one of claims 21 to 26, wherein the electrode body forms one electrode of a plurality of electrodes positioned to be exposed to the plasma confinement chamber, and one or more of the plurality of electrodes comprises an electrode material that releases hydrogen gas for use in plasma generation above a threshold temperature. 28. A thermonuclear fusion reactor, a plasma confinement chamber; an electrode at least partially enclosed within the plasma confinement chamber, the electrode including a nose cone that intersects an axis of a plasma arc that is confined within the plasma confinement chamber during operation of the thermonuclear fusion reactor; 1. A thermonuclear fusion reactor comprising: a liquid metal meniscus formed on a surface of a nose cone, the liquid metal meniscus directly interacting with a confined plasma arc during operation of the thermonuclear fusion reactor. 29. The thermonuclear fusion reactor of claim 28, wherein the electrode includes a plurality of internal channels and an internal reservoir, the internal reservoir being in fluid communication with the liquid metal meniscus via at least a first portion of the plurality of internal channels. 30. The thermonuclear fusion reactor of claim 29, wherein a second portion of the plurality of internal channels supplies fuel gas to the plasma confinement chamber. 31. The thermonuclear fusion reactor of claim 29 or 30, wherein a third portion of the plurality of internal channels contains a heat exchange fluid that maintains the temperature of the electrodes and / or the liquid metal meniscus. 32. A thermonuclear fusion reactor as described in any one of paragraphs 29 to 31, further comprising a first supply channel fluidly connecting the internal reservoir to a liquid metal source, the liquid metal source being positioned outside the plasma confinement chamber. 33. The thermonuclear fusion reactor of claim 32, further comprising a second supply channel fluidly connecting the internal reservoir to a source of inert gas, the source of inert gas being positioned external to the plasma confinement chamber. 34. A method comprising: flowing a liquid metal from an internal reservoir of the electrode onto an exterior surface of the electrode at a liquid metal flow rate; generating a confined plasma arc to ablate liquid metal from the exterior surface at a liquid metal ablation rate; and adjusting the liquid metal flow rate by adjusting one or more of the liquid metal level in the internal reservoir, the inert gas pressure in the internal reservoir, or the liquid metal temperature in response to the liquid metal flow rate deviating from the liquid metal ablation rate by more than a threshold magnitude. 35. Flowing liquid metal at a liquid metal flow rate is providing liquid metal to an internal reservoir up to a liquid metal level; 35. The method of claim 34, comprising: supplying inert gas to the internal reservoir until the inert gas pressure is satisfied. 36. The method of claim 34 or 35, wherein flowing the liquid metal at a liquid metal flow rate includes maintaining the liquid metal temperature by flowing a heat exchange fluid through the electrode and / or regulating heat from an internal heating coil of the electrode. 37. The method of any one of paragraphs 34 to 36, wherein adjusting the inert gas pressure includes increasing the inert gas pressure on average over the life of the electrode. 38. A method according to any one of paragraphs 34 to 37, wherein the liquid metal flow rate is not zero before and after adjusting the liquid metal flow rate. 39. in response to the liquid metal level being below the threshold level; stopping the flow of liquid metal from the internal reservoir; Item 39. The method of any one of items 34 to 38, further comprising removing at least a portion of the liquid metal from the exterior surface by increasing the liquid metal temperature. 40. The method of any one of paragraphs 34 to 39, further comprising adjusting the liquid metal ablation rate by adjusting the repetition rate of the discharge current that maintains the confined plasma arc.

[0163] The specification and drawings are to be regarded in an illustrative rather than a restrictive sense, however it will be apparent that various modifications and changes may be made thereto without departing from the broader spirit and scope of the invention as set forth in the appended claims.

[0164] Other variations are within the spirit of the disclosure. Thus, while the disclosed technology is susceptible to various modifications and alternative constructions, certain illustrated embodiments thereof are shown in the drawings and have been described above in detail. It is to be understood, however, that there is no intention to limit the invention to the particular forms or configurations disclosed, but on the contrary, the intention is to cover all modifications, alternative constructions, and equivalents within the spirit and scope of the disclosure as defined by the appended claims.

[0165] The use of terms such as "a," "an," and "the," and similar referents in the context of describing the disclosed embodiments (particularly in the context of the claims that follow) should be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. Similarly, the use of the term "or" should be construed to mean "and / or," unless expressly stated or otherwise contradicted by context. Terms such as "comprising," "having," "including," and "containing" should be construed as open-ended terms (i.e., meaning "including, but not limited to"). When referring to an unmodified physical connection, the term "connected" should be construed as partially or completely contained within, attached to, or joined together, even if there is something intervening. The recitation of ranges of values ​​herein is merely intended to serve as a shorthand method of referring individually to each separate value falling within the range, and each separate value is incorporated herein as if it were individually recited herein, unless otherwise indicated herein. Unless otherwise indicated or contradicted by the context, use of the term "set" (e.g., "set of items") or "subset" should be construed as a non-empty set containing one or more members. Furthermore, unless otherwise indicated or contradicted by the context, the term "subset" of a corresponding set does not necessarily indicate a proper subset of the corresponding set, and the subset and the corresponding set may be equivalent. Unless otherwise indicated by the context, use of the phrase "based on" means "based at least in part on" and not "based solely on."

[0166] Conjunctions such as phrases of the form "at least one of A, B, and C" or "at least one of A, B and C" (i.e., the same phrase with or without the Oxford comma) are understood to be generally used in context to indicate an item, term, etc., either A or B or C, any non-empty subset of the set A and B and C, or any set that contains at least one A, at least one B, or at least one C and that is not contradicted or otherwise excluded by the context, unless expressly stated otherwise or clearly contradicted by the context. For example, in the illustrative example of a set having three members, the conjunctions "at least one of A, B, and C" and "at least one of A, B, and C" refer to any of the following sets: {A}, {B}, {C}, {A, B}, {A, C}, {B, C}, {A, B, C}, and, unless expressly or contextually contradictory, any set having {A}, {B}, and / or {C} as a subset (e.g., a set having multiple "A"s). Thus, such conjunctions are not intended to generally mean that a particular embodiment requires that at least one of A, at least one of B, and at least one of C are each present. Similarly, phrases such as "at least one of A, B, or C" and "at least one of A, B, or C" refer to the same thing as "at least one of A, B, and C," and "at least one of A, B, and C" refers to any of the following sets: {A}, {B}, {C}, {A, B}, {A, C}, {B, C}, {A, B, C}, unless a different meaning is expressly stated or clear from the context. Furthermore, unless the context indicates otherwise or is contradictory, the term "plurality" refers to a plurality (e.g., "a plurality of items" refers to a plurality of items). The number of items in a plurality is at least two, but may be more if indicated explicitly or by context.

[0167] The operations of the processes described herein may be performed in any suitable order unless otherwise indicated herein or clearly contradicted by context. In one embodiment, processes such as the processes described herein (or variations and / or combinations thereof) are performed under the control of one or more computer systems configured with executable instructions, implemented by hardware or a combination thereof as code (e.g., executable instructions, one or more computer programs, or one or more applications) that collectively execute on one or more processors. In one embodiment, the code is stored on a computer-readable storage medium, e.g., in the form of a computer program including a plurality of instructions executable by one or more processors. In one embodiment, the computer-readable storage medium is a non-transitory computer-readable storage medium that excludes transitory signals (e.g., propagating transient electrical or electromagnetic transmissions), but includes non-transitory data storage circuitry (e.g., buffers, caches, and queues) within a transceiver of the transitory signals. In one embodiment, code (e.g., executable code or source code) is stored on a set of one or more non-transitory computer readable storage media that, when executed (i.e., as a result of being executed) by one or more processors of a computer system, store executable instructions that cause the computer system to perform the operations described herein. In one embodiment, the set of non-transitory computer readable storage media includes a plurality of non-transitory computer readable storage media, where one or more of the individual non-transitory storage media of the plurality of non-transitory computer readable storage media are absent of all of the code, while the plurality of non-transitory computer readable storage media collectively store all of the code. In one embodiment, the executable instructions are executed such that different instructions are executed by different processors. For example, in one embodiment, the non-transitory computer readable storage media store instructions, and the main CPU executes some of the instructions, while the graphics processing unit executes other instructions. In another embodiment, different components of the computer system have separate processors, with the different processors executing different subsets of the instructions.

[0168] Thus, in one embodiment, a computer system is configured to implement one or more services that singly or collectively perform the operations of the processes described herein, such computer systems being configured with applicable hardware and / or software that enable the execution of the operations. Further, in embodiments of the present disclosure, the computer system is a single device, and in other embodiments, a distributed computer system comprising multiple devices operating differently such that a distributed computer system performs the operations described herein, and such that no single device performs all operations.

[0169] The use of any and all examples or exemplary language (e.g., "etc.") provided herein is intended merely to better describe embodiments of the invention and does not impose limitations on the scope of the invention unless otherwise claimed. No language in the specification should be construed as indicating any non-claimed element essential to the practice of the invention.

[0170] Embodiments of the present disclosure are described herein, including the best mode known to the inventors for carrying out the invention. Variations of those embodiments will become apparent to those skilled in the art upon reading the foregoing description. The inventors expect those skilled in the art to adopt such variations as necessary, and the inventors intend for the embodiments of the present disclosure to be carried out in ways other than as specifically described herein. Accordingly, the scope of the present disclosure includes all modifications and equivalents of the subject matter recited in the claims appended hereto as permitted by applicable law. Moreover, any combination of the above-described elements in all possible variations thereof is encompassed by the scope of the present disclosure unless otherwise indicated herein or clearly contradicted by context.

[0171] All references cited in this specification, including publications, patent applications, and patents, are herein incorporated by reference to the same extent as if each reference was individually and specifically indicated to be incorporated by reference and was set forth in its entirety herein.

Claims

1. 1. A plasma confinement system comprising: a plasma confinement chamber; An electrode body, a nosecone positioned to be exposed to the plasma confinement chamber; an internal reservoir fluidly connected to a liquid metal source, the liquid metal source supplying liquid metal to the internal reservoir during operation of the plasma confinement system; a plurality of internal liquid flow channels extending into a surface of the nosecone to fluidly connect the internal reservoir to the plasma confinement chamber.

2. 2. The plasma confinement system of claim 1, wherein a first portion of the liquid metal forms a protective film between the surface of the nose cone and the plasma confinement chamber during operation of the plasma confinement system, and a remaining second portion of the liquid metal is delivered from the liquid metal source to the internal reservoir and along the plurality of internal liquid flow channels toward the surface of the nose cone during operation of the plasma confinement system.

3. The plasma confinement system of claim 2 , wherein the protective film is maintained at a predetermined thickness during operation of the plasma confinement system.

4. 2. The plasma confinement system of any one of the preceding claims, wherein the electrode body is formed from one or more of a metal, graphite, or a semiconductor.

5. 13. The plasma confinement system of any one of the preceding claims, wherein the electrode body is coaxial with a direction of gravity, and the nosecone is positioned below the internal reservoir with respect to the direction of gravity, and wherein extending from the internal reservoir, each internal liquid flow channel of the plurality of internal liquid flow channels is initially oriented upwards and opposite to the nosecone, from which each internal liquid flow channel of the plurality of internal liquid flow channels arches downwards and towards the nosecone.

6. each internal liquid flow channel of the plurality of internal liquid flow channels comprising: a primary liquid flow channel fluidly connected to and extending from the internal reservoir; 6. The plasma confinement system of claim 2, further comprising: a plurality of liquid flow capillaries fluidly connecting the main liquid flow channel to the plasma confinement chamber, the protective film being held on the surface of the nosecone via capillary action induced by the plurality of liquid flow capillaries.

7. 10. The plasma confinement system of claim 9, wherein the electrode body forms one of a plurality of electrodes positioned to be exposed to the plasma confinement chamber, and one or more of the plurality of electrodes comprises an electrode material that releases hydrogen gas for use in plasma generation above a threshold temperature.

8. 1. A thermonuclear fusion reactor, comprising: a plasma confinement chamber; an electrode at least partially enclosed within the plasma confinement chamber, the electrode comprising a nose cone that intersects an axis of a plasma arc confined within the plasma confinement chamber during operation of the thermonuclear fusion reactor; a liquid metal meniscus formed on a surface of the nosecone, the liquid metal meniscus directly interacting with the confined plasma arc during operation of the thermonuclear fusion reactor.

9. 9. The thermonuclear fusion reactor of claim 8, wherein said electrode comprises a plurality of internal channels and an internal reservoir, said internal reservoir being in fluid communication with said liquid metal meniscus through at least a first portion of said plurality of internal channels.

10. 10. The thermonuclear fusion reactor of claim 9, wherein a second portion of said plurality of internal channels supplies a fuel gas to said plasma confinement chamber.

11. 11. The thermonuclear fusion reactor of claim 9 or 10, wherein a second portion of the plurality of internal channels contains a heat exchange fluid that maintains a temperature of the electrodes and / or the liquid metal meniscus.

12. 12. The thermonuclear fusion reactor of any one of claims 9 to 11, further comprising a first supply channel fluidly connecting the internal reservoir to a liquid metal source, the liquid metal source being located external to the plasma confinement chamber.

13. 13. The thermonuclear fusion reactor of claim 12, further comprising a second supply channel fluidly connecting said internal reservoir to a source of inert gas, said source of inert gas being located external to said plasma confinement chamber.

14. 1. A method comprising: flowing a liquid metal from an internal reservoir of the electrode onto an exterior surface of the electrode at a liquid metal flow rate; generating a confined plasma arc to ablate the liquid metal from the exterior surface at a liquid metal ablation rate; and adjusting the liquid metal flow rate by adjusting one or more of a liquid metal level in the internal reservoir, an inert gas pressure in the internal reservoir, or a liquid metal temperature in response to the liquid metal flow rate deviating from the liquid metal ablation rate by more than a threshold magnitude.

15. flowing the liquid metal at the liquid metal flow rate, supplying the liquid metal to the internal reservoir up to the liquid metal level; and supplying an inert gas to the internal reservoir until the inert gas pressure is satisfied.

16. 16. The method of claim 14 or 15, wherein flowing the liquid metal at the liquid metal flow rate comprises maintaining the liquid metal temperature by flowing a heat exchange fluid through the electrode and / or regulating heat from an internal heating coil of the electrode.

17. The method of any one of claims 14 to 16, wherein adjusting the inert gas pressure comprises increasing the inert gas pressure on average over the lifespan of the electrode.

18. The method according to any one of claims 14 to 17, wherein the liquid metal flow rate is non-zero before and after adjusting the liquid metal flow rate.

19. in response to the liquid metal level being below a threshold level, stopping the flow of the liquid metal from the internal reservoir; The method of any one of claims 14 to 18, further comprising removing at least a portion of the liquid metal from the exterior surface by increasing the liquid metal temperature.

20. The method of any one of claims 14 to 19, further comprising adjusting the liquid metal ablation rate by adjusting a repetition rate of a discharge current that maintains the confined plasma arc.

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