Particle generation device

Abstract

A particle generator and a system including the same are provided. The inertial electrostatic confinement particle generator includes a vessel, an anode structure, and a cathode structure, the anode structure and the cathode structure being disposed within the vessel. The particle generator further includes a first enriched surface enriched with a fusible isotope species, the first enriched surface being at least a portion of a surface of the anode structure or a surface of the cathode structure.

Description

[Technical field]

[0001] The present disclosure relates to an inertial electrostatic confinement type particle generator, in particular a particle generator having an anode structure, a cathode structure, and a first enriched surface, the first enriched surface being enriched with a fusible isotope species, the first enriched surface being at least a portion of a surface of the anode structure or a surface of the cathode structure. [Background technology]

[0002] In artificial fusion, a force is utilized to impart the appropriate kinetic energy to fusion capable isotopic species (FIS). FIS consist of isotopes of hydrogen (hydrogen, deuterium and tritium) and helium-3 for the purpose of neutron and proton generation, respectively. Alternative FIS such as boron and lithium are possible in combination with the aforementioned isotopes. Forces in the form of any combination of magnetic plasma confinement, particle beam accelerators, pulsed laser heating, and electromagnetic confinement fields are used to focus the ions into a collision zone. The first fusion technology successfully commercialized was the Inertial Electrostatic Confinement (IEC) neutron generator. In IEC, the reactor vessel contains a mesh-like cathode at the center, the inner wall of which acts as the anode. The chamber is filled with FIS gas and a high voltage is applied to the cathode, creating a strong electric field that accelerates the ions into the chamber and ignites a plasma at the center of the cathode where fusion occurs. IEC neutron generators can generate up to 5×10 neutrons per second for deuterium-tritium fusion. 9 They have demonstrated the reliable capability to produce a continuous neutron flux of neutrons for tens of thousands of hours with little or no maintenance.

[0003] Several means are known to produce ions and mitigate the collisions that only cause losses. Methods to produce low energy ions include electron emitters or dispenser cathodes that provide electrons that can oscillate around one or two external grids. Ionization of the external region close to the anode wall can contribute ions to the "pass zone" for directing to the spokes or beam. There are some doubts regarding losses such as defocusing that may be introduced. However, the complexity of the fabrication and the resulting costs are too high for the increased performance. The reliability and long life of the additional insulator standoffs, the delicate large grids, the additional vacuum electrical supply through the penetrations in the closed system, as well as the short operating life of the electron emitters, and the deleterious effects of the aggressive hydrogen gas plasma atmosphere on the dispenser cathode are all drivers for a more cost-effective technology. In addition, the electron emitters require significant power within the atmosphere of the operating IEC environment.

[0004] Existing IEC arrangements use aluminum or stainless steel as the material for the anode and molybdenum or tungsten for the cathode due to their secondary electron emission properties, heat resistance, low cost and ease of manufacture. However, in applications requiring high particle generation rates, more suitable materials could be used to improve these properties and thus increase the particle generation rate. In particular, there is a need for materials that can accommodate high concentrations of photoions and exhibit substantial secondary electron emission.

[0005] Many different multi-particle interactions can be used to create nucleons. Some examples of such fusion reactions and the particle kinetic energy created are:

[0006]

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[0007] The reactions in Equations 1-4 above show a variety of available particles and energies depending on the mix of FIS. If fusion can be produced in a controlled environment such as a particle generator or fusion reactor, the higher energy and lower mass reactions can be collimated and attenuated to be utilized in many different ways. In particular, the higher energy neutrons and protons in Equations 3 and 4 are unique in that they are otherwise difficult or impossible to produce by means other than fusion. The particles in Equations 1 and 2 can be produced by fission reactions, which are rich in neutrons at 2.45 MeV, or by particle accelerators, where protons can be accelerated by electromagnetic fields up to 3.02 MeV.

[0008] Neutrons are extremely useful, but they present challenges in being cheap, reliable, safe and on-demand. Historically, Californium-252 neutron sources have been the standard, but the constant and uncontrolled release of neutrons imposes complex operational safety requirements. Furthermore, the material's half-life of 2.5 years means the source has a short lifetime, as well as inherent disposal complexities and costs.

[0009] Currently available alternative technologies are advanced tube neutron generators or miniature linear accelerators. Typically this takes the form of a source of deuterium ions that are linearly accelerated into a focused beam by an electric field onto a solid or gaseous tritium target to induce the fusion reaction and neutron production. Although such systems have been commercialized, their use is limited by their large initial and running costs. This is mainly due to the infrastructure required to operate the accelerator, the unintentional activation of materials from stray energetic deuterium fluence, as well as the erosion or burning of the tritium target, which requires periodic replacement. This also means that the systems are not capable of operating continuously for long periods of time. Description of the Prior Art

[0010] A particle generator device is described in WO 03019996. The generator in WO 03019996 is described with a focus on differences from linear geometry long-life plasma gas target line source topology particle generating devices.

[0011] WO 03019996 discloses a cylindrical IEC device with low neutron production rate, high reliability and simplicity, which also proposes the use of aluminum for the anode wall, since it emits electrons when exposed to intense ultraviolet radiation, which accelerates the ionization process mentioned above. Summary of the Invention

[0012] According to some embodiments of the present disclosure, there is provided an inertial electrostatic confinement particle generator, the particle generator comprising: a vessel; an anode structure; a cathode structure, the anode structure and the cathode structure being disposed within the vessel; and a first enrichment surface, the first enrichment surface being enriched with a fusion-capable isotope species. The first enrichment surface is at least a portion of a surface of the anode structure or a surface of the cathode structure. The enrichment surface is capable of promoting lattice confinement fusion.

[0013] The apparatus may be configured to include a mixture of ions and a neutral gas and, during operation, to cause the mixture of ions and a neutral gas to form a plasma.

[0014] The vessel of the device may include a central axis. The anode and cathode structures may be arranged such that the anode and cathode structures are substantially coaxial with the vessel, the anode structure having an average distance from the central axis that is greater than the average radius from the central axis of the cathode structure. The anode and cathode structures may be substantially concentric along at least a portion of their lengths and may be configured such that during operation an electric field is provided between the anode and cathode structures such that the first concentrated surface is electronically shielded. This electronic shielding may promote lattice confinement fusion. The vessel may also have a substantially constant cross section coaxially along the length of the cathode structure. The anode may be formed from a plurality of anode units.

[0015] The first enriched surface may be formed of a basic metal or a transition metal. The metal may be an element with an atomic number greater than 40, and more specifically may be one of titanium, zirconium, palladium, or erbium. Preferably, the metal may be zirconium. Alternatively, the first enriched surface may be formed of a semiconductor material. The semiconductor material may be CVD diamond.

[0016] The first concentrating surface may be provided as a coating on the anode or cathode structure, or alternatively, the first concentrating surface may be integrally formed with the electrode that forms at least a portion of the surface.

[0017] The device may be configured such that during operation the device produces nuclear particles, which may be neutrons or protons.

[0018] In the case of a device configured to generate protons during operation, the device may further comprise a fluid conducting structure proximate to the anode structure. These fluid conducting structures may be constructed from a metal alloy. Additionally, these fluid conducting structures may include corrugations along the length of the fluid conducting structures.

[0019] The first concentration surface may be configured to cover a portion of a surface area of ​​the anode structure or the cathode structure such that, during operation, the generated particles have a localized flux having a predetermined geometric shape.

[0020] In some embodiments, the first enriched surface can form at least a portion of a surface of an anode structure and the second enriched surface can form at least a portion of a surface of a cathode structure, the second enriched surface being enriched with the fusible isotope species.

[0021] According to the present disclosure, there is provided a system including a plurality of particle generators, each particle generator being as described above and configured such that a single power source can power several systems. [Brief description of the drawings]

[0022] For a better understanding of the present disclosure and to show how it may be carried into effect, reference will now be made, by way of example, to the accompanying drawings in which: [Figure 1] 1 illustrates a cut-through of an Inertial Electrostatic Lattice Confinement (IELC) ​​device, according to some embodiments. [Diagram 2] 1 illustrates a cross-sectional view of an anode and cathode geometric layout for a proton generator configuration of an IELC according to some embodiments. [Diagram 3] FIG. 13 shows a cross-sectional view of a further proton generator IELC for the generation of PET radioisotopes according to some embodiments. [Figure 4] FIG. 1 illustrates a proton generator system functional schematic for a medical isotope production configuration, according to some embodiments. [Diagram 5]1 illustrates a multiple unit configuration in parallel with localized anode enrichment according to some embodiments. [Figure 6] 13 illustrates a further multiple unit configuration in series including localized anodic concentration according to some embodiments. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0023] Lattice confinement fusion (LCF) theory and measurements have demonstrated fusion reactions occurring in solid metals under electronic screening conditions. Here, the negatively charged electron cloud present in the conductive metal neutralizes the positive charge of fusion-capable ions located in the metal lattice. The incident accelerated ions are not repelled by the electrostatic forces normally found between two positively charged particles, allowing the fusion reaction seen below to occur with less energy required and at enhanced rates. In "Strong Screening by Lattice Confinement and Resultant Fusion Reaction Rates" by Prados-Estevez, F., Subashiev, A., and Nee, H., it was discussed how the top ten valence electrons in a given metal can nullify the Coulomb potential between fusion-capable isotope species, thereby increasing the fusion reaction cross section and allowing fusion at high rates in solid metals. Saturation effects are also expected and are found to occur.

[0024] The LCF effect varies little between FIS or their associated reactions, but does vary for different host metals due to their inherent shielding potential. In IELC systems, the stability of the implanted hydrogen species at high temperatures and in the presence of radiation is of paramount importance. This limits suitable candidate materials to those such as palladium, erbium and zirconium, among others. Extensive work on the hydride properties of Zr has been carried out in relation to its use as a fuel cladding alloy in nuclear fission reactors, emphasizing its stability at high temperatures and in the presence of high doses of radiation.

[0025] Electrolysis represents a rapid and efficient method to load any mixture of deuterium or tritium into the zirconium lattice at atomic percentage levels without the use of ion beams or complex metallurgy, which represents a viable manufacturing route for the FIS enriched cathodes or FIS enriched anodes described in this disclosure.

[0026] Furthermore, the electron emission of the cathode grid can greatly affect the fusion rate. The use of grids of the same geometric shape made of different metals gives a significant difference in the fusion rate with all other parameters being the same. An advantageous material candidate for the anode or cathode is single- or polycrystalline CVD diamond, which shows excellent performance at high power input, high thermal conductivity, high thermal and radiation hardness, as well as strong thermionic emission properties. Furthermore, it is possible to grow CVD diamond on tungsten, for example, using deuterium and / or tritium plasma mixtures that enrich the material to atomic percent concentrations of FIS.

[0027] In the embodiment of the present disclosure, the electric potential is positive at the anode and negative at the cathode, so when the neutral gases are ionized, they become positive ions that are repelled from the anode surface and attracted to the cathode surface, and thus accelerated toward the plasma. Electron emission can occur at the cathode surface due to a combination of thermionic and photoelectric effects. Electrons emitted from the cathode are repelled from the cathode and accelerated toward the anode due to the negative charge. These high energy electrons are secondary electrons that ionize the neutral gases at the anode wall, and then accelerate toward the cathode due to their positive charge, contributing to the plasma.

[0028] Ions carried on the anode surface may contribute more to fusion since they are accelerated over a greater distance by the electric field into the potential well inside the cathode. The use of FIS-enriched materials in the anode or cathode may not only increase lattice-confined fusion in the material compared to conventional IEC, but at the right temperature the FIS may diffuse into the reactor chamber, ionize, and contribute significantly to the particle production rate of the system. Careful control of the temperature of the anode with precise cooling may allow for the controlled release of FIS into the chamber to maintain the increased particle production rate. This may be managed by an automated system that manages the power, particle production rate, and temperature to provide a stable output.

[0029] As is well established, all systems can saturate at a steady state where particle production is constant. In the present disclosure, saturation occurs except for the further reason that at a given temperature, an equilibrium exists between the degradation of the hydride surface layer and the steady release of ions due to the assimilation of hydrogen isotopes into the lattice bulk. This process can be beneficial or detrimental to the particle production rate, depending on the materials used for the anode and cathode. Nevertheless, careful control of the cathode and anode temperatures is key to maximizing the particle production rate of the system. For very high particle production rates approaching the neutron flux density of a 1 MW nuclear fission reactor, it can be advantageous to use a cryogenic system.

[0030] A particular advantage of the embodiments of the present disclosure is that the neutron output can be made extremely consistent when reaching steady state when run at a fixed power input as described above, which means that it is relatively easy to remove extraneous noise effects in practical applications of the present disclosure by an appropriate noise subtraction process. Thus, the embodiments of the present disclosure can provide an apparatus for generating a nuclear fusion reaction rate with high stability as defined by the measurable neutron flux at a particular voltage, current and temperature condition.

[0031] According to the present disclosure, materials that can contain high levels of fusion-capable ionic species, such as Zr or CVD diamond, promote LCF as well as secondary electron emission. This is especially true for CVD diamond, a semiconductor with an indirect band gap in the UV region, but with much better thermal properties and relatively easy techniques for application to complex geometric surfaces used in tool manufacturing. It is therefore possible to combine the particle generation techniques of increased secondary electron emission and lattice confinement fusion by enhancing the anode and cathode material surfaces. Axial cylindrical IELC systems can also have improved fusion rates. Such measures may be incorporated into the embodiments of the present disclosure.

[0032] The electrodes may be made of these materials or may alternatively have a coating of a suitable material, including CVD diamond, molybdenum, tungsten, zirconium and other basic or transition metal elements, potentially rare earth elements.

[0033] Thus, embodiments of the present disclosure can provide an apparatus for generating nuclear fusion reactions utilizing the properties of an Inertial Electrostatic Lattice Confinement (IELC) ​​device with ions initially generated by glow discharge decomposition of reactive gases in a plasma gas mixture and ion and electron bombardment processes, as well as the preferred generation of low energy secondary electrons well suited for further ion generation after high energy electron and ion bombardment of structures located at or near the anode wall, as well as the generation of FIS from the anode wall. Two complementary phenomena act to increase the particle generation rate.

[0034] 1. Generation of secondary electrons from the cathode surface, increased by material selection. These electrons gain significant energy from the electric field and are accelerated into the anode walls. The cathode material may also be enriched with fusible species to promote lattice-confined fusion events and increase plasma density.

[0035] 2. Enrichment of the inner surface of the anode with fusible species in a suitable metal such as titanium, zirconium, palladium, erbium, or a semiconducting material, e.g., CVD diamond, which induces fusion events confined to the lattice and produces secondary electrons that allow the ions carried by the anode to ionize and contribute to the particle generation rate in the central cathode region, thus electronically shielding the material.

[0036] The operating temperatures of the anode and cathode are typically related to their ability to increase the rate of particle production.

[0037] Figure 1 shows a diagram of a cut-through model of the neutron generation configuration for an IELC particle generator. Figure 1 shows components such as 1 outer chamber wall, 15 high voltage standoff components, 17 cathode assembly, and 34 local fusible isotope species enriched inner anode surface.

[0038] Specifically, Figure 1 shows an IELC cut-through showing a flanged cylindrical cathode encompassing the anode surface and ceramic insulators added to both ends containing voltage feed-throughs. The IELC devices referred to in this disclosure can include fusible ionic species enriched anode 34 and / or cathode 17 materials. These materials can be selected for their secondary electron emission properties and ability to retain high levels of fusible ionic species at high temperatures while remaining stable, including, but not limited to, zirconium, titanium, aluminum, other rare earth metals, high entropy alloys and their associated oxides and hydrides. Figure 1 represents a simplified neutron generator configuration in which deuterium or tritium gas species are released and stored in a getter material within a sealed vessel.

[0039] Embodiments of the present disclosure may provide an apparatus for generating nuclear fusion reactions utilizing the properties of a so-called star mode of operation, which refers to an operating mode in which a plasma is generated inside the apparatus. As a result, embodiments are envisioned in which the apparatus includes a mixture of ions and neutral gases and is configured to cause the mixture of ions and neutral gases to form a plasma during operation.

[0040] Additionally, embodiments of the present disclosure can provide an apparatus for generating nuclear fusion reactions utilizing an ion trapping phenomenon referred to as a "pass zone", whereby a spatial region centered on each star beam and having a curved funnel-like shape with its widest end at the anode wall defines a region where ions carried with relatively low kinetic energy can be drawn from the gas plasma, anode and / or cathode surfaces into the local star beam.

[0041] The shape of the cathode grid 17 may be adapted such that the formation and shape characteristics of the star mode beam and pass zone are controlled to maximize or at least improve the above-mentioned generation and utilization of ions for fusion collisions. The grid 17 may be constructed from panels, which may be shaped to extend longitudinally to form a hollow cylinder or a cylindrical skeletal frame. The cathode grid 17 may comprise flanges, which may be made from the aforementioned panels. These flanges may distribute the electric field between the cathode grid and the anode such that the electric field is concentrated near the flanges to generate beams or channels. For example, these channels may be formed between nearby, adjacent or adjacent flanges. These beams or channels may improve the acceleration of the generated ions towards the plasma, which may be located at the center of the electric field and / or where the beams or channels intersect. These electric field channels may be considered to be pass zones. Thus, an embodiment of the present disclosure is provided in which the generated nucleons can escape from a sealed device in all directions from the origin zone, which can replace a source made of many individual pellets of a radioactive neutron emitting isotope that is long in length, e.g., Californium 252, or an individual point source such as a point source neutron generator device.

[0042] Thus, embodiments of the present disclosure can provide an apparatus for generating a fusion reaction in a volume or zone as defined above, extending from the centerline to the anode and including the space outside the inner cathode and the inner cathode at a radial distance of about half the radius of the cathode 17, as well as the inner wall of the anode 34, which is suitably enriched with a fusible isotope species. Furthermore, embodiments of the present disclosure can provide an apparatus for generating a fusion reaction in an elongated zone or multiple zone segments in the case of a curvilinear geometry within the reactor vessel. In other words, embodiments of the present disclosure can provide an apparatus for generating a fusion reaction in a volume centered on the centerline axis or cylindrical symmetry line of the reactor vessel.

[0043] Unlike a typical linear accelerator, the nucleons produced by the embodiments of the present disclosure can be multidirectional. The embodiments of the present disclosure aim to replace the powerful unidirectional beams of several millimeters in diameter of accelerated energy protons made by particle accelerator devices that strike a target causing relatively rapid damage. Compared to linear accelerators, the present disclosure can spread the proton production over a larger precursor material volume that can be easily processed to easily extract pure isotopes for use. Thus, the embodiments of the present disclosure can provide an apparatus for generating nuclear fusion reactions for periods of thousands of hours to years with little or no maintenance on the reactor chamber containing the FIS enriched anode and / or cathode. Similarly, the embodiments of the present disclosure can provide an apparatus for generating nuclear fusion reactions with little or no maintenance on the central electrode 17 or associated high voltage power input structure, little or no maintenance on the internally mounted gas storage and pressure regulation device of the reactor chamber, and / or little or no maintenance on the internally mounted conduit structure for aqueous fluid between the substantially thin foil thickness vacuum vessel wall 1 and the inward facing wall. The materials selected for the cathode and anode may be selected to promote secondary electron emission, resistance to thermal damage, and lattice containment fusion.

[0044] Furthermore, as described above, the device may be adapted so that ions carried or generated within the pass zone between the anode wall and the periphery of the cathode grid 17 may be drawn into a star mode beam having a cathode hole window side segment curvature that can be adapted to the shape of the equipotential plane in the electrostatic field to increase the size of the pass zone, around which the pass zone can be substantially centered, thereby capturing most or substantially all of the ions generated by the interaction of secondary electrons and neutral particles near the anode wall 34.

[0045] FIG. 2 shows an integrated vessel. Specifically, FIG. 2 shows a cross-sectional view of the anode and cathode geometric layout for the proton generator configuration of the IELC. FIG. 2 shows the following components: 2 corrugated chamber walls, 3 corrugated thin FIS enriched anode surfaces, 4 outer chamber surfaces, 5 anode wall components, 6 anode support structure, and 17 cathode assembly. The walls and heat transfer components 1 can provide the advantage of reduced manufacturing costs. Thus, embodiments of the present disclosure can provide an apparatus for generating increased nuclear fusion reaction rates with several reactant gas ionization enhancements compatible with low maintenance and low cost systems. The components can be manufactured as extrusions of aluminum alloys by known means, such as aluminum extruded through suitable holes. The fluid or gas conduits and anode walls of the combined functions can be manufactured from stainless steel or materials of similar properties to achieve manufacturability and functionality. An advantageous vessel topology has an eight-sided polygonal form, in other words an octagonal cross section. This topology can have improved robustness over topologies with more vertices. For example, a cross section with a larger number of vertices can allow for a higher degree of symmetry and therefore an increased number of fluid conducting structures. These fluid conducting structures can act as cooling channels for the device. However, a cross section with more vertices can be more expensive to build and less robust. A cross section with fewer vertices can be vulnerable to temperature fluctuations due to a reduced number of fluid conducting structures and an increased effect of material impurities. An octagonal cross section can be a desirable compromise between these two extremes. Thus, embodiments of the present disclosure can provide an apparatus for generating nuclear fusion reactions that is structurally robust for operation in a moving vehicle. Similarly, embodiments of the present disclosure can provide an apparatus for neutron or proton producing nuclear fusion reactions that is structurally robust for operation at hospital locations in static or mobile systems.

[0046] The central cathode 17, the anode structure 3 / 6 and the outer chamber or vessel 4 may be coaxial. In particular, the vessel 4 may include a central axis, and the anode structure and the cathode structure may be arranged such that the anode structure 3 / 6 and the cathode structure 17 are substantially coaxial with the vessel. The anode structure 3 / 6 may have an average distance from the central axis that is greater than the average radius from the central axis of the cathode structure 17, and the anode structure and the cathode structure are substantially concentric along at least a portion of their lengths, and are configured such that during operation, an electric field is provided between the anode structure and the cathode structure, and the first concentrated surface is electron shielded. The vessel 4 may have a substantially constant cross section coaxially along the length of the cathode structure. Thus, embodiments of the present disclosure may provide an apparatus for generating nuclear fusion reactions in a curvilinear source configuration that may conform to the curved linear form of a particular object to be irradiated.

[0047] The exterior can have integral cooling fins 2 sized to fit within a cylindrical housing 4. The housing 4 can act as a cowling or duct for a coolant fluid (such as air) to facilitate heat transfer from the fins 2 to the passing fluid. It is feasible to use a liquid coolant to transfer a larger heat flux. It is also feasible to use a liquid coolant such as water circulated in a piping system brazed to the vessel wall 1.

[0048] In this embodiment, in proton generation mode, the anode wall may be constructed to provide a conduit for the precursor fluid, and is therefore characterized by an inner wall that acts as the electric anode of the reactor. The side of the conduit that is not directly exposed to the cathode may have a structural function. The inner wall may have a function that is central to the intended function of the present improvement.

[0049] Detailed inset A (2:1) of FIG. 2 shows, for illustrative purposes, a cross section of one example of an inserted fluid conduit and concentrated anode wall component 5 that can be located on the surface of the inner wall of the vessel 1. As mentioned above, there are well-known phenomena that can be exploited to increase the production of low energy electrons. Ionization of reactive gas species (not shown) can provide a high intensity flux of UV photons that can fill the vessel wall 1. The incidence of high energy electrons accelerated by the strong electrostatic field of the present disclosure can cause the emission of low energy secondary electrons. These low energy electrons can be well suited for ionizing hydrogen and helium. The collection of ions near the concentrated anode 1 can be greatly increased. To ensure an increase in the low incidence angle of the high energy electrons flowing towards the anode in a local radial direction, the surface can be shaped as shown by the waveform 3. The height of the peaks can be low to keep them within the electrostatic field potential zone where maximum ionization efficiency can be achieved. The width of the ridges 3 can also be small to fit as many as possible into the available area. Design considerations can be influenced by manufacturing costs. If the vessel wall 1 and anode structure 6 are based on cylindrical tube sections, it is also acceptable to fabricate the ionization-enhancing ridges 3 as threads or helical tubes on the inner wall surface. These may run circumferentially rather than longitudinally as in the case of extrusions.

[0050] As shown in FIG. 2, the anode structure 6 may be formed from multiple anode wall elements 6 and enhancing ridges 3. In other words, the anode structure 6 can be considered to be formed from multiple anode units and equipped with one or more holes and / or windows. The holes or windows of the cathode grid in combination with the anode wall can help to determine a surface of equal electrostatic potential. When the device is operating in star mode, a lens effect can be generated by the superposition of the charge spaces of ions and electrons. The shape of the electrostatic lens can be changed by modifying the geometry of the anode and cathode, for example by incorporating: a) Approximately concentric circles for the cathode and anode b) a regular even number of sides of a polygon for the inner wall of the anode and a corresponding number of windows on the cathode, the periphery of the windows generally being: 1. Convex 2.Flat 3.Concave 4. A combination of the above three compounds, A regular even number of sides of a polygon and a corresponding number of windows on the cathode, each having a defined radius of curvature and arc segment length for repeated use throughout the stack of cathode grid cells, such that the formed star beam can be optimized or tailored for secondary electron generation at the anode and mitigation of ion collisions with the cathode grid electrode.

[0051] Techniques such as 3D printing of the cathode can improve transparency and facilitate the electric field that directs ions and electrons to impinge on the anode surface. Also, desirable metallurgical properties for handling high temperatures and high secondary electron yields imply that treatment with CVD diamond on the surfaces of the anode and cathode is also advantageous, along with the enrichment of fusion-capable ionic species.

[0052] Additionally, the anode wall may be treated by passive means to promote the generation of multiple emissions of relatively low energy electrons that can most easily ionize the reactant gas species isotopes when the surface of the anode wall is bombarded by relatively high energy electrons accelerated by the applied electrostatic field present during star mode glow discharge ionization operation. Such passive means may include coating the substrate metal with rare earth elements or CVD diamond with beneficial properties, and / or providing a surface finish with texture or fine geometry to promote the generation of secondary electrons. To achieve this, the anode and / or cathode may also act as electrodes during enrichment with fusible isotope species by electrolysis, by filling the chamber with enough heavy water (deuterated and / or tritiated), inserting electrodes, and applying a sufficient current density to the inner surface to promote hydrolysis. This forms a hydride enriched layer on the inner anode wall. This can then be treated by CVD plasma using a deuterium and / or tritium gas mixture to grow several microns of diamond on the material surface.

[0053] Alternatively to the above method, the production of FIS enriched anode and / or cathode materials can be carried out by hydrolysis, in which case the reactor vessel can be filled with a deuterated or tritiated heavy water solution containing conductive salts for electrolysis. Another cathode made of a material such as platinum in a gauze mesh can be inserted into the vessel so that the internal electric field is equally distributed when voltage is applied, allowing for uniform formation of hydrides. Prior to hydrolysis, chemical etching can be carried out to remove surface oxides. This process can be carried out in parallel in several reactor units using the same power supply, which may require several kW capacity, if liquid cooling can be beneficial for the reactor vessel to limit the adverse effects of heating on the electrolyte conductance. Transition metal hydrides are also possible for cathode materials, in which case the same process is carried out in a suitable reaction vessel with surrounding platinum gauze for the same purpose. It is also anticipated that embodiments of the present disclosure may require a wire mesh to maximize the LCF effect due to the increased surface area, in which case the wire can be subjected to electrolysis continuously while being threaded through a U-shaped platinum gauze mesh at a suitable speed and applied voltage. By controlling the penetration rate and applied voltage, the hydride layer can be made uniform over its length.

[0054] The failure mode of any metal coating on the insulating surface can be mitigated by providing a generally radial trajectory of both ionized and neutral particles of gas atoms, molecules and metal particles such that the metal atoms move towards either end of the electrode stack where the non-conductive electrode support structure is located so that the failure mode can be prevented or at least reduced.

[0055] The corrugated concentrated anode walls can have the secondary effect of increasing the surface area of ​​the concentrated anode, which can allow for higher loading of fusion-capable ionic species into the device. This can have the additional effect of increasing the number of anode-carrying ions and therefore further increasing the particle production rate. The present disclosure is not limited to the structures shown as alternative designs that can provide higher surface areas are possible, and the added surface area can be traded off for added complexity and cost.

[0056] The corrugated concentrated anode wall 3 may have a thickness determined by the energy loss of energetic protons that is allowed to ensure that the residual energy is optimal for the protons to interact with designated target nuclei that are incorporated into the molecules or solute molecules of the fluid contained within the conduit 5. This wall thickness may be in the range of 0.01 to 0.5 mm.

[0057] The anode, secondary electron generating means, vessel walls and external heat transfer fins etc. may be integrated into a cross-sectional form suitable for manufacturing by extrusion or 3D printing processes to produce a low-cost part of the device. Thus, embodiments of the present disclosure may provide a device for generating increased nuclear fusion reaction rates with several reactant gas ionization enhancements compatible with low-maintenance and low-cost systems.

[0058] In embodiments, including the embodiment shown in FIG. 2, the conduit enrichment anode wall 5 can be manufactured by fabrication of a stainless steel backplate and a stainless steel or otherwise metallic FIS enrichment corrugated front wall. The backplate may be machined or milled to produce a typical wall thickness of at least 2 mm. The enrichment anode wall 3 can be processed by known techniques to roll or press the desired corrugations of the desired wall thickness within the tolerance range. Such a process can provide a design option with selective reinforcing strips to counteract deformation due to operating pressure differentials. The two components may be welded together if the materials are compatible with electron beam, laser, or other concentrated focused energy welding techniques to form the anode wall fluid conduit subassembly 6. In the embodiment shown in FIG. 2, such a subassembly can be slid into place within the vessel wall 1.

[0059] In an embodiment, the fluid conduit structure may be fabricated from a rolled steel backplate having a cross-sectional profile matching the extruded slot inside the substantial vessel wall, and a thin sheet pressed or otherwise formed into the anode wall of a corrugated profile, and the two components are welded together to achieve an ultra-high vacuum compatible seal.

[0060] In one embodiment of the present disclosure, the fluid conduit anode wall structure may have a relatively thin anode wall with a characteristic thickness that may range from 0.05 mm to 0.5 mm. This thickness may be defined by the reduction in kinetic energy of 14.7 MeV protons that is allowed for the residual energy range to be sufficient for nuclear interactions with certain isotopes concentrated within the fluid, and may also apply to the length of the traverse path of protons passing through the anode wall at angles other than 90 degrees of incidence. This may include protons generated in the anode wall by lattice confinement fusion that may indicate emission from an internal surface curvature.

[0061] In one embodiment of the present disclosure, the thin anode wall of the duct structure can have an intricate chemically etched surface in which stiffener features, which may or may not be FIS enriched, are aligned with the cathode grid cells to better withstand the thermal stresses imposed by the impingement of a star mode beam.

[0062] The thin anode walls of the conduit structure can be achieved by well-known techniques such as chemical etching and protective masking, whereby structural reinforcement features and relatively thin windows can be defined and created on the anode walls of the conduit structure if deemed necessary. Chemical etching can be used to achieve the thin anode walls, which has the added benefit of promoting anode surface purity and aiding the hydrolysis process to maximize enrichment of fusible isotope species.

[0063] FIG. 3 shows the reaction chamber and integrated fluid conduit subsystem assembly of one embodiment of the present disclosure. Specifically, FIG. 3 shows a cross-sectional view of a proton generator IELC for generating PET radioisotopes. The following labeled components are: 1 outer chamber wall, 6 anode support structure, 7 fluid conduit end block, 8 connecting stub tube, 9 manifold assembly, 10 pipe joint fitting, 11 precursor fluid inlet / outlet, 12 end cap assembly, 13 gas supply end cap assembly, 14 seal gasket, 15 high voltage standoff components, 16 FIS gas fitting flange, and 17 cathode assembly. The lengths are cut diagrammatically so that the ends of the reaction chamber can appear on one page. The overall length may range from 1 to 2 meters. The vessel wall 1 can hold eight enriched anode wall fluid conduit assemblies 6, two of which are shown in cross-section. The central cathode assembly 17 is symbolically shown. The internal features of each end may be milled to provide better access and accommodation of the fluid conduit assemblies. Each fluid conduit may have an end assembly consisting of an end block 7 and a stub tube 8 which may be brazed or otherwise attached to achieve a leak-free or ultra-high vacuum standard seal. The stub tubes 8 may be inserted into a manifold assembly 9 at each end of the chamber 1. The high vacuum seal connection of each stub tube may be achieved by suitable tube fittings 10 of the weld-on type which may be welded to the stainless steel manifold 9.

[0064] The inlet and outlet 11 may be similarly implemented by welded pipe joint fittings 10 .

[0065] The manifold 9 may be closed by an end cap assembly 13. A high voltage supply through the end cap assembly 12 may provide a high vacuum seal, and the gas supply end cap assembly 13 may also provide a high vacuum seal. The sealing gasket 14 may be a "metal O-ring" device. An array of clamping screws may be provided that act against the flanges, not shown, to clamp the flange faces against the "metal O-ring" seal to achieve a particular deformation and high vacuum seal.

[0066] The gas supply endcap assembly 13 can be connected to a gas management subsystem that can be implemented as separate gas pressure regulators for each reactant gas type or as a combination gas pressure regulator for Helium 3 and a getter pump for Deuterium. The gas supply endcap assembly 13 can enclose a high voltage standoff component 15 that allows free movement of gas between the main chamber and a gas port 16.

[0067] An embodiment of the present disclosure may incorporate means for circulating the target fluid through the conduit structure of the fusion fuel loaded anode wall components so that necessary cooling of the fluid, the anode wall, and associated reactor vessel structure may be implemented, as well as means for delivering the newly formed product isotope-containing compounds to an external location where chemical means of extraction and concentration may be placed in a closed recirculation circuit. Thus, the aforementioned target fluid may be considered to include a proton capture region.

[0068] The circular or polygonal reaction chamber may also be modified to create a wider chamber in which the fluid conduits 6 are arranged in two parallel planes, with any practical width being determined by the number of fluid conduits 6 that can be accommodated side-by-side protruding out of the plane of Figure 3. However, this may result in a reduction in the proton capture area of ​​the fluid conduits 6.

[0069] There is also a particle production rate advantage from operating in pulsed power mode. This is likely due to a combination of lattice confined fusion, concomitant electron screening effects, and secondary electron emission. Periodic relaxation of the voltage may allow a higher concentration of valence electrons to briefly return to the surface increasing the secondary electron yield and stronger electron screening effects increasing lattice confined fusion. Thus, to maximize the gain from operating in pulsed mode, the frequency of the pulses must be matched to the relaxation time it takes for the electrons to relocate to the concentrated surface after extensive ionization. Thus, embodiments of the present disclosure can provide a device that can utilize pulsed power input, whereby the current is on the order of a few amperes to tens of amperes during the pulse, thereby taking advantage of the observed fusion rate enhancement property of superlinear proportionality with the applied current.

[0070] FIG. 4 is a system functional schematic. Specifically, FIG. 4 shows a proton generator system functional schematic for a medical isotope production configuration. The following labeled components are: 18 high voltage power supply, 19 low voltage pulse driver, 20 gas management manifold subsystem, 21 helium-3 reservoir, 22 turbomolecular vacuum pump, 23 residual reservoir, 24 primary vacuum pump, 25 getter pump, 26 sealed vessel, 27 cathode assembly, 28 manifold assembly, 29 heat exchanger, 30 isotope extraction system, 31 fluid flow circuit pump, 32 helium-3 input valve, and 33 control computer system.

[0071] The embodiments of the present disclosure may have peripheral functions interfaced for effective operation. An important peripheral may be an ultra-high voltage pulsed current power supply, typically consisting of a high voltage transformer section 18 and a low voltage pulse driver section 19. For IEC devices described in the prior art, the number of particles generated scales linearly with the power input. In contrast, the embodiments of the present disclosure may provide an increase in particle generation rate over comparable IEC systems, such as prior art IEC systems, while having lower power requirements. Thus, the peripheral support equipment required to support a high wattage power supply is no longer necessary, since a large number of particles can be produced with a smaller power input. The embodiments of the present disclosure may provide an apparatus for increasing the fusion reaction rate with minimal or reduced amount of peripheral support equipment functions.

[0072] The getter pump assembly 25 may be located external to the reaction chamber assembly in FIG. 4 or may be within a manifold assembly symbolically shown within boundary line 20. The non-evaporative getter pump may be supported by a power supply, a heating element, and temperature measurement circuitry (not shown). The power supply may provide sufficient voltage and current to power a heater element that may be embedded within the getter pump getter material. The heater may raise the getter material to a temperature in the range of 400° C. to 600° C. The heater may be controlled so that the getter material remains at a steady temperature. The vessel 26 may be sealed and evacuated after proper baking to remove residual volatiles such as water. A conditioned getter of suitable material may have a partial pressure of 5×10 when in the temperature ranges mentioned above. -3 mbar~5×10 -1Hydrogen or its isotopes can be released so that the partial pressure rises to mbar levels. At a certain steady temperature, the partial pressure can also be steady. A constant temperature getter pump can act as a high precision pressure source and pressure regulator. Very small pressure fluctuations can cause significant deviations in the star mode glow discharge voltage. Although pressure regulation can be fine enough with an open bleed valve and turbomolecular vacuum pump configuration, a getter pump can provide an excellent means of pressurization for IELC devices in a closed configuration.

[0073] The capacity of the getter pump 25 for storing the reactive gas (deuterium) can be a determining factor for the maximum number of operating hours of the closed reactor chamber. A practical configuration can achieve a maximum of 1×10 per second. 14 A fusion rate of 10 times the energy of the fusion reaction can allow for 10 years of continuous deuterium consumption. During such a period, the power output of a closed reactor can be expected to change very slowly as the reactant mixture ratio changes. In the D-He3 embodiment, several DD fusion reactions can occur. Tritium and Helium 3 can be produced as well as protons (hydrogen). Helium 3 and tritium can be accumulated or consumed in the applicable fusion reaction. The contribution of these side reactions may be minimal in practice. The fusion rate in this embodiment is 1×10 per second, depending on the fusible species enrichment level. 10 ~1×10 14It is likely that the reaction chamber is evacuated to a low pressure. It is possible to perform maintenance on the sealed chamber by opening the fill and vent ports (not shown), extracting the gas by heating the getter pump, and baking the chamber to induce outgassing of volatile species embedded in the inner wall surfaces 3 and 1 of FIG. 2, FIG. 3. Handling tritium may be subject to safety regulations. However, the amount of tritium that may accumulate in a commonly used D-He3 reactor embodying the present disclosure is expected to be below the minimum safety threshold for handling and transport in most countries. The gas management manifold subsystem 20 may also include a reservoir of helium-3 within the pressure vessel 21. When service operations are performed, the reaction chamber is evacuated to the minimum practical pressure level. The high cost of helium-3 is pumped down to a pressure of 1-5×10 by a turbomolecular vacuum pump 22. -2 A scavenging system may be required to direct the residual helium 3, which may be at an initial partial pressure of mbar, into the reservoir 23 for reuse.

[0074] Embodiments configured to utilize Helium 3 may have external means to store and condition the Helium 3, and ultimately handle and separate the Helium 4, in addition to a getter pump for the deuterium gas.

[0075] The overall gas manifold subsystem may include a primary vacuum pump 24 for initial evacuation and support of subsequent operating procedures. A number of dosing and shutoff valves (shown generically) may be included to support the implementation of automated configuration control.

[0076] The concentrated anode and vessel walls may comprise combined functional elements and may incorporate external fins or other heat transfer structures or surfaces for heat transfer by flow of a heat transfer fluid, typically a cooling fluid, over the fins or other structures or surfaces.

[0077] More specifically, an embodiment for isotope production can have a chamber assembly 26 in which the vessel wall or anode wall can be lined with fluid conduit assemblies 27, of which there are eight in one embodiment. These can be connected at each end to a manifold assembly 28 to ensure that the contained aqueous fluid is sealed from the vacuum-like environment of the reaction chamber. The manifold assembly can include ports that allow for the configuration of a fluid flow circuit. The fluid flow circuit can include the main functional feature of a heat exchanger 29 to remove a significant portion of the heat delivered to the chamber by the high voltage power supply. Further functional features of the fluid circuit can be a means for extracting PET isotopes 30 and a particulate filtration system. The fluid flow circuit can be completed by a pump 31. All components may have to be medical device standard.

[0078] For the purposes of this embodiment, there may be software that controls the glow discharge voltage, pulse current and pulse duty cycle that the high voltage power supplies 18, 19 can deliver. The voltage may be determined by the gas pressure in the chamber 26. The gas pressure may be determined by the getter pump temperature, which may be measured by a temperature measurement circuit and transmitted to the software. The getter pump temperature may determine the deuterium partial pressure. The software may command the getter pump heater power supply to deliver more or less power to maintain the getter pump temperature. The software may also command the dosing servo valve control unit to maintain the pressure. This software function may control the deuterium partial pressure, which is determined by the getter pump 25 and the helium 3 dosing valve 32, so that the mixture ratio of the two gaseous elements may be equal in terms of atomic number. Commands or control signals may be issued to the necessary subsystems so that the reactor operates at or very close to the parameters required for optimal production of the isotope. The control algorithm is non-trivial due to some non-linear characteristics. However, the response time may be long enough that a typical computer with the necessary input and output ports or a dedicated microprocessor controlled computer 33 can easily handle the periodic monitoring and control tasks. The net result may be that a steady state proton production rate is achieved.

[0079] A further feature of the present disclosure is the ability to automate all processes, ensuring high reliability, redundancy, and safety standards. The auxiliary equipment shown in FIG. 4 can be monitored and controlled by a central control unit 33 computer system. Such a system can have a user interface, for example, so that a qualified operator can supervise and give high level commands to the PET isotope production system. The central control unit 33 can ultimately be automatically driven by a software program that oversees the safety interlocks, start-up and shutdown sequences, normal steady state operating parameters, and management of minor and major anomalies. The operator can also input specific control parameters, command the proton generator system to initiate a warm-up mode, initiate a proton generation mode, stop the proton generation mode or transition from the proton generation mode to a standby state, resume the proton generation mode, and finally initiate a total shutdown of the system. Control of the fluid circulation subsystem may be controllable, but preferably automated to support the reaction chamber cooling function. There may be a subset of functions related to the operation of the isotope filter 30.

[0080] An inherent capability of the IELC is its low-cost scalability. Typically, the use of two point sources doubles the cost of the neutron source. This is acceptable for some commercial neutron analysis systems where Cf-252 was the only practical source. However, it is more problematic for neutron irradiation systems that use two neutron generator devices. Since each individual neutron generator system consists of a reactor device, a high-voltage power subsystem, an electronic controller subsystem, and an auxiliary cooling subsystem, multiple copies of the equipment are required. Operation of two or more closed-tube devices connected in parallel with one set of appropriately specified auxiliary subsystems appears to offer only a minor cost reduction compared to two separate closed-tube neutron generator sets. IELC systems can be physically connected in series through continuous tubes as well as electrically connected in parallel. This allows for significant cost reductions in the more expensive components of the system, the power supplies, and the ceramic insulators. This means cost savings when scaling up such systems as opposed to alternative accelerator-based generators. Furthermore, such a geometric configuration provides a more uniform neutron fluence over a large sample area for fusion materials testing or isotope generation in large volume vessels where a similar fluence would be prohibitively costly to replicate in accelerator-based systems.

[0081] Preferably, the device may be adapted to generate neutrons in a "macro" linear or curvilinear shape, the term "macro" being used to distinguish between relatively small "micro" sized neutron source shapes, such as a single pellet of a radioisotope, and "mega" sized neutron sources, such as a nuclear fission reactor core or star. In other words, "macro" refers to a size or scale useful for industrial applications. This may range from source lengths of about 1 cm for the envisaged medical neutron beam source application, to several meters for mine exploration, soil analysis or other similar applications. The macro characteristic also means that macro-scale devices can be constructed from an ordered collection of micro-sized units. Parallel or perpendicular alignment allows for higher flux densities, where controlled enrichment of the anode walls allows for weighting of particle production rates to specific regions of the macro system. This is the case in certain embodiments of the present disclosure, which efficiently stack micro-star beam cells into a linear arrangement that may consist of two or more cells, typically several tens of cells.

[0082] FIG. 5 depicts a parallel configuration of systems 35 presenting an embodiment for compact, large volume radioisotope production or material irradiation, where the inner anode surface 34 facing the irradiation area is locally enriched in FIS, facilitating particle production in close proximity to the LCF and high flux irradiation area. The following labeled components are 34 localized fusible isotope species enriched inner anode surface, 35 outer vessel wall, and 36 cathode assembly. This geometric configuration allows for more uniform flux over a larger volume area, making it ideal for fusion material testing for critical subsystems such as bleeder blankets, superconducting magnets, and heat extraction systems. Thus, embodiments of the present disclosure can provide an apparatus for generating fast and reproducible fusion reaction rates in mass-produced embodiments.

[0083] Suitably, the cathode structure or cathode assembly 36 may have an open surface around its periphery and is surrounded by the anode and vessel wall structure. The cathode structure may include a plurality of cathodes stacked from prism end to prism end with substantially identical electrode structures to establish an elongated array that may establish a stable plasma gas dynamic structure in a star mode beam of ions oscillating in a substantially radial direction in star mode operation, where a nuclear fusion reaction may occur in which the emitted neutrons are likely to be seen by an outside observer with appropriate neutron detection instruments to originate from a zone defined by the interior volume space of the anode electrode and the interior surface or wall of the vessel. The prism end of the electrode refers to the flat surface of the end of the electrode when the electrode is formed in a prismatic shape, e.g., cylindrical. In the present disclosure, protons may behave similarly, but do not escape the reactor vessel. Thus, embodiments of the present disclosure may provide an apparatus that contains a nuclear fusion reaction to produce protons and other reaction products contained within the reactor vessel wall and a relatively small neutron flux that can escape the containment device in all directions from the elongated origin region. FIG. 6 represents a series of configurations of the system presenting an embodiment for scanning large moving objects such as those in luggage or shipping containers moving rapidly on a conveyor belt or train. In other words, FIG. 6 shows a multiple unit configuration arranged in series, including a local anode enrichment. The following labeled components are 37 local fusible isotope species enriched inner anode surface, 38 outer container wall, 39 cathode assembly, 40 central high flux irradiation area. Preferably, the FIS enriched inner anode wall surface 39 can enable a concentrated uniform flux across the hexagonal axial plane. The series connected cathode structure 38 can include a high voltage feedthrough overlapping with a separate ceramic insulator 40 to avoid short circuit arcing.

[0084] Multiple cathode structures 38 connected in series may be individually referred to as a cathode cage cell. Thus, embodiments of the present disclosure may provide an apparatus for generating a nuclear fusion reaction in a zone whose length may be specified as a multiple of a single cathode cage cell length. Examples of characteristic dimensions of possible embodiments are: I. Inner diameter of anode and vessel wall: 8 cm II. Cathode grid electrode diameter 3cm III. Length of cathode grid electrode: 80cm IV. Length of proton source: 80cm V. The total length of the reactor chamber VI and the power assembly is 180 cm.

[0085] The embodiments of the present disclosure functioning as generators are well suited to disposing beryllium, nickel or lead formed within the slot-in anode wall structure so that the generated neutrons or protons can have nuclear interactions with these elements or other elements similarly incorporated within the reactor chamber walls to generate additional nuclear particles.

[0086] The disclosed embodiments functioning as proton generators are well suited for the production of radioisotopes used in positron emission tomography. This is because the nuclear fusion reaction between deuterium and helium-3 releases protons with an energy of 14.7 MeV. It has been found that proton energies in the range of 8-18 MeV are required to react with oxygen-18 to produce the PET isotope fluorine-18. As protons pass through a metallic membrane or foil, the kinetic energy of the protons drops. For example, protons of a given energy may penetrate about 1.5 times deeper into aluminum than into steel. In practice, for 14.7 MeV protons, the anode wall thickness may need to be less than about 0.3 mm to have an exit proton energy of 8 MeV. An even thinner anode wall thickness may raise the residual proton energy available for the intended interaction with the target isotope nucleus. If engineering evaluation results in the selection of stainless steel for more favorable properties for manufacturing, a typical wall thickness may be in the range of 0.05-0.5 mm, with a preferred value of 0.1 mm.

[0087] PET scanning equipment has had to be located in close proximity to devices such as proton accelerators that generate energetic protons. This improvement provides an energetic proton source and target irradiation device with the capacity to support patient PET scanning protocols and potentially with significantly lower manufacturing and operating costs. Essential subsystems include a fusion reactor vessel, a compact high voltage pulsed power supply, a system for reactant gas pressure regulation and storage, a system for target fluid circulation and / or cooling, and a system for isotope recovery, separation and purification.

[0088] The precursor fusion fuel gas may generally consist of fusible isotopes at low pressure suitable for induced glow discharge. -3 mbar~5×10 -1The getter pump (mbar) may be fitted with a chemical non-evaporative getter pump that may have the characteristics to produce a constant hydrogen isotope partial pressure for a constant temperature of the getter material. The getter pump may function as a gas storage and pressure regulator in a hermetically sealed chamber and may be useful in practical industrial embodiments of the present disclosure. The getter temperature may be controlled by automated means to maintain a target voltage across the electrodes, which is determined by the gas plasma pressure. The partial pressure of Helium 3 may be controlled by a closed loop controller of a micro-dosing valve combined with a deuterium getter pump. Depending on the fuel consumption rate and product gas production, occasional purge cycles may be devised. The high voltage power supply preferably has a pulse current capability that may be used to establish a nearly constant average power input to the IELC device. This may result in corresponding stable fusion and isotope production rates. Pulsed operation with a pulse duration of 5 to 100 microseconds is believed to be optimal for mitigating local hot spots on the cathode that may act as a source of arcing and resulting severe local heating. The life of the reactor chamber assembly may be limited by metal deposition on the internal insulator surfaces. Avoiding this relies on utilizing microchannel beam distribution to mitigate metal vapor migration to the ceramic feedthrough and standoff insulator surfaces. The dimensions of the cathode may be such that radiant heat is effectively transferred to the anode chamber walls and then further transferred to the external cooling system via circulating fluid in a conduit. This ensures that the operating temperature of the cathode grid remains low enough to effectively mitigate significant metal vapor pressure as well as decomposition of deuterium and / or tritium containing hydrides. The use of CVD diamond coatings on the cathode and anode can minimize thermal stress and metal evaporation while promoting secondary electron emission, meaning that sputtering of the surface by the plasma can release carbon ions, which have less adverse effect on the energy of the plasma compared to heavier metal ions that suck up free electrons.

[0089] Due to the lack of charge on neutrons, the present disclosure is suitable for fast neutron imaging and diagnostic techniques, where the probed material suffers little or no measurable damage after interrogation, as most of the particles pass through and the measured perturbations come from dynamic elastic interactions that tend to leave the material relatively undamaged. These elastic interactions vary between isotopes of the same element, making this technique uniquely useful for investigating the atomic composition of suspect packages, valuable archaeological artifacts or unidentified technology. The same is true for biological targets, if the total dose is kept below an appropriate level.

[0090] While passing through the material, neutrons can cause nuclear reactions with the target nuclide either through a threshold reaction, where with sufficient energy the nucleus splits into residual nuclides, or through a thermal neutron capture event, which transforms the nuclide into a different isotope or element that emits secondary particles such as gamma rays. Secondary gamma emission spectra from neutron capture reactions are well documented and demonstrate applications such as neutron activation analysis, thermal neutron analysis and rapid gamma neutron activation analysis. 9 n.s. -1 Even particle generators with a low neutron production rate (NPR) of 1000 keV can easily detect isotopes with large neutron capture cross sections, such as Nitrogen-14 or Uranium-235, given sufficient exposure time and gamma detection equipment. With higher NPR and more sensitive gamma detection equipment, materials can be probed over a wide area and their atomic composition assessed with high precision. Until now, this has only been possible with the use of nuclear fission reactors or expensive accelerators.

[0091] In some applications, the neutron flux needs to be precisely defined in order to be generally accepted as part of an approved medical therapy. The quality of the neutron flux from accelerator sources or sealed tube neutron generators is considered to be less than ideal. Accelerator spallation neutron sources can produce a range of neutron energies, making them more difficult to mitigate and thermalize than monoenergetic sources. Sealed tube devices provide monoenergetic neutrons, but suffer from unreliable neutron output, similar to accelerator spallation sources. The solid targets used by these devices suffer from changes in properties due to damage sustained with use. The combined electrostatic lattice confinement fusion of fusible ions from a neutral gas and ion mixed plasma does not suffer from target degradation, since the damage is distributed across the anode and cathode surfaces, and the diffusion and injection processes reach equilibrium during operation. Also, the FIS is continuously updated with a steady state in the plasma. Reactive gas contamination can be mitigated so that the neutron output quality can be constant for a given set of controllable operating parameters.

[0092] The combined Inertial Electrostatic Lattice Confinement (IELC) ​​fusion device represents a highly versatile particle generator, with selected isotopic fusion capable species producing the monoenergetic particle spectrum of energies seen through Equations 1-4. These modes can then be further tuned by altering the operating conditions such as the power input of voltage and current in direct or pulsed configurations, as well as the operating temperature of the anode, meaning that the total particle production rate of each setting can be tailored to the specific application for which the generator is constructed. Examples of different applications of the IELC include a proton generator for producing PET medical radioisotopes, a neutron generator for diagnostics and imaging or neutron activation applications, as well as pulsed mode neutrons for the detection of explosives and fissile materials.

[0093] In conjunction with the capability of continuous neutron output, an advantage that any electric neutron generator should offer is the ability to repeatedly switch on and off to create a pulsed mode of operation. Pulsed mode duty cycles can range from minutes or seconds of on-time and similar off-time intervals to milliseconds, microseconds, or even nanoseconds. It may not be necessary, cost-effective, or practical to offer the entire pulsed duty cycle range in every neutron generator. The main advantage of the pulsed mode is to block noise caused by higher energy neutron interactions and then detect thermal neutrons or other delayed interactions where prompt gamma photons are not instantaneously released. The implementation of mechanical shutters to make a Cf-252 or fission-based beam hole source into a quasi-pulsed neutron source is not practical or cost-effective. Additionally, from a safety perspective, the concept of a particle generator with a built-in kill switch is very attractive.

[0094] Non-point source geometry can be advantageous in the design of neutron collimation systems. Such peripheral systems can include neutron deceleration to reduce the average energy of the collimated neutron flux. The purpose of neutron collimation is to establish a neutron beam with a specific flux density and neutron energy characteristics. Neutrons are not charged particles and therefore do not respond to electrostatic or magnetic fields. Collimation devices rely on the interaction of neutrons with specific materials to obtain reflection and refraction-like velocity changes. It can be envisioned that embodiments of the present disclosure can provide new conceptual configurations of neutron sources and collimation systems for specific applications. Beryllium, lead and nickel can act as such multipliers, moderators and reflectors for neutron collimation. The fluence of neutrons can be forced to some degree, masked and directed to create specific flux patterns for different purposes. In the fusion industry, this is particularly useful for component irradiation testing where the fluence expected at that point in the reactor can be reproduced by a combination of masking, principle and collimation.

[0095] The sealed tube neutron generator technology is essentially age limited by the inevitable erosion of the solid target. This component is a metal such as titanium impregnated with tritium or deuterium gas. The incident energetic deuterium has the effect of causing sputter erosion of the target. The sputter products condense as a metal film on the inner surface of the sealed tube device. Using voltages in the vicinity of 100 kilovolts, the metal film will short circuit as it accumulates. Even before this ultimate failure mode, the highly localized beam will cause hot spots and associated gas depletion in the target. Although various neutron yield degradation mitigation schemes have been used, the fact remains that the best guaranteed life of a sealed tube neutron generator is only 4000 hours. The present disclosure spreads the thermal and radiation damage during operation over a larger surface area of ​​the anode and cathode, resulting in an inherent advantage in durability compared to accelerator-based competitors.

[0096] A common problem with the lifetime of both spherical and cylindrical IELC devices is based on observations of experimental units where stainless steel wire electrodes suffer structural failure after perhaps 10-20 hours of operation at voltages ranging from 20-60 kilovolts and applied currents of about 5-30 milliamps. The mode of failure is metal vaporization or corrosion and deposition on the surface of the insulator components, which inevitably leads to a short circuit condition. The lifetime of a system according to the present disclosure may exceed the claimed lifetime of commercially available closed tube beam solid target neutron generators by 50% and is expected to operate indefinitely. In some embodiments of the present disclosure, a mean time between failures of 20,000 hours or more may be expected.

[0097] For commercial success, embodiments of the present disclosure are simple enough to allow manufacturing, operation and maintenance costs to be lower than the life cycle costs associated with competing accelerator-based particle generators as a result of the reduced number of parts in the assembly, low part manufacturing costs, rapid assembly and inexpensive quality assurance checks. Individual components or subassemblies have high durability in their intended functions within embodiments of the present disclosure. The combination of subsystems and their functions preferably reduces operational control of variable parameters to allow operation of the system by less trained personnel through a higher degree of automation.

[0098] The present disclosure can be configured as the core of a compact system for the production of specific isotopes for use by medical or non-biological tomographic scanning processes such as positron emission tomography (PET) scanning. Positron emission tomography utilizes a pair of 511 keV gamma photons resulting from the positron (positively charged electron or antimatter electron) decay of a specific radioactive or unstable isotope, where the annihilation of the positron and electron produces a nucleus with a rest mass (i.e., 2 MeC 2 ) into two gamma ray photons that are generally emitted with exactly opposite velocity vectors. Gamma detection sensors are typically placed in a ring through which the patient or object being scanned passes. With sufficient volume and time, the detected 511 keV emissions can be mapped to build a tomographic or three-dimensional data field that can be presented as visual slices or three-dimensional models of the internal structures of the scanned object or patient. Other processes in the technology use x-ray or beta particle emitters of similar energy for the same purpose, but produce lower fidelity images or deliver radiation therapy to specific areas of the body. More recently, elements such as zirconium, which happens to have both beta and x-ray emitting isotopes, can be used to diagnose areas of the body that have cancer, as well as to deliver radiation therapy doses in an effective and precise treatment known as theragnostics.

[0099] The choice of isotope that may be used for a PET scan is determined by biomedical considerations that are too complex for useful discussion here. Commonly listed PET isotopes, their half-lives, and the reactions they produce are as follows:

[0100]

number

number

number

[0101] The conventional method of producing these isotopes is to have a concentrated source isotope in a target medium, such as an aqueous solution. The target solution is bombarded by a stream of energetic protons with enough energy to allow penetration of the barrier and still have enough residual energy for the necessary nuclear interactions that result in the formation of the desired isotope. The wall thickness is typically that of a metal foil (0.1-5 mm).

[0102] The proton source is usually a particle accelerator of the cyclotron or linear accelerator type, with the proton energy imparted usually greater than 5 MeV. Some linear accelerators are imparted with proton energies of 12 MeV. The proton beam intensity is a current of several milliamps with focal characteristic dimensions of a few millimeters in diameter. This constitutes an enhanced spot of radiation and heat generation. The engineering problem faced by designers of this kind of PET isotope production system is the extremely localized and intense thermal energy generated in the target medium. This can include the superheating of water, which requires pressurization to keep it in liquid form for the most efficient proton-nuclear collisions. The present disclosure provides a system with significantly lower running costs, since ions only need to be accelerated to energies of a few hundred keV to produce fusion particles of the order of 14 MeV. Furthermore, the thermal stresses on the device as well as the vessel containing the precursor isotopes are spread over a larger area, meaning less complexity and the need to replace parts regularly. Accelerator-based particle generators have difficulty spreading the proton beam over a large area, whether by direct acceleration or by spallation fusion reactions. As a result, such systems have high maintenance costs and are difficult to operate continuously, as the irradiated material requires periodic replacement due to sputter erosion and proton damage.

[0103] The present disclosure therefore provides for longer intervals between maintenance of the combined particle generator and target subsystem, and inherently lower manufacturing costs. The heat flux imposed per unit area or volume of the target is much lower because a proton beam is not utilized and the proton flux is uniformly distributed across the entire interior surface area of ​​the reactor chamber wall. This further reduces the complexity and costs associated with the cooling subsystem.

[0104] The present disclosure has the capability to serve the radioisotope needs of a cluster of hospitals within a containment area. Many hospital hubs exist in urban centers around the world, each within a short distance of one another for logistical purposes. A deuterium-deuterium or deuterium-tritium neutron mode system can be installed in the basement of one hospital within a shielded area to produce, for example, Mo-99 and Lu-177 for other hospitals within the containment area. Alternatively, a deuterium-helium 3 mode proton generating system can be paired with a mobile PET scanner from a secure vehicle. Such a system is suitable for simultaneous generation of multiple isotopes, for example, with separate channels containing oxygen-18 or oxygen-16 water to produce fluorine-18 or nitrogen-13, respectively. Each isotope can be chemically extracted on demand from the circulating fluid.

[0105] Although various aspects of the exemplary embodiments of the present disclosure may be illustrated and described as block diagrams, flow charts, or using some other diagrammatic representations, it is to be appreciated that these blocks, apparatus, systems, techniques, or methods described herein may be implemented, by way of non-limiting examples, in hardware, software, firmware, special purpose circuits or logic, general purpose hardware or controllers or other computing devices, or any combination thereof.

[0106] References in this disclosure to "one embodiment," "an embodiment," or the like indicate that the described embodiment may include a particular feature, structure, or characteristic, but not all embodiments need to include the particular feature, structure, or characteristic. Moreover, such phrases do not necessarily refer to the same embodiment. Moreover, when a particular feature, structure, or characteristic is described in connection with an embodiment, it is believed to be within the knowledge of one of ordinary skill in the art to implement such feature, structure, or characteristic in connection with other embodiments, whether or not explicitly described.

[0107] In this specification, terms such as "first", "second" and the like may be used to describe various elements, but it should be understood that these elements should not be limited by these terms. These terms are used only to distinguish one element from another. For example, a first element can be referred to as a second element, and similarly, a second element can be referred to as a first element, without departing from the scope of the present disclosure. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed terms.

[0108] The terms used herein are for the purpose of describing particular embodiments only and are not intended to limit the disclosure. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms unless the context clearly indicates otherwise. It will be further understood that the terms "comprises", "comprising", "has", "having", "includes" and / or "including", as used herein, specify the presence of stated features, elements, and / or components, but do not exclude the presence or addition of one or more other features, elements, components, and / or combinations thereof. As used herein, the terms "connect", "connects", "connecting" and / or "connected" cover direct and / or indirect connections between two elements.

[0109] The present disclosure includes any novel feature or combination of features disclosed herein, either explicitly or in any generalization thereof. Various modifications and adaptations to the foregoing exemplary embodiments of the present disclosure may become apparent to those skilled in the art in view of the foregoing description, when read in conjunction with the accompanying drawings. However, any and all modifications fall within the scope of the non-limiting and exemplary embodiments of the present disclosure. For the avoidance of doubt, the scope of the present disclosure is defined by the claims.

Claims

1. An inertial electrostatic confinement type particle generation device, comprising: a container; an anode structure; a cathode structure, wherein the anode structure and the cathode structure are disposed within the container; a first enrichment surface, wherein the first enrichment surface is enriched with fusible isotope species, and the first enrichment surface is at least a part of the surface of the anode structure or the surface of the cathode structure; A particle generation device comprising the above.

2. The particle generation device according to claim 1, wherein the device contains a mixture of ions and a neutral gas, and is configured to form a plasma in the mixture of ions and the neutral gas during operation.

3. The container includes a central axis, the anode structure and the cathode structure are arranged so as to be substantially coaxial with the container, the anode structure has an average distance from the central axis greater than the average radius from the central axis of the cathode structure, the anode structure and the cathode structure are substantially concentric along at least a part of the lengths of the anode structure and the cathode structure, an electric field is provided between the anode structure and the cathode structure during operation, and the first enrichment surface is configured to be electron shielded. The particle generation device according to claim 1.

4. The particle generation device according to claim 1, wherein the container has a substantially constant cross section coaxially along the length of the cathode structure.

5. The particle generation device according to claim 1, wherein the anode structure is formed from a plurality of anode units.

6. The particle generation device according to claim 1, wherein the first enrichment surface is formed from a basic metal or a transition metal.

7. The particle generation device according to claim 6, wherein the metal is an element having an atomic number of 40 or more.

8. The particle generation device according to claim 7, wherein the element is one of titanium, zirconium, palladium, or erbium.

9. The particle generation device according to claim 1, wherein the first enrichment surface is formed from a semiconductor material.

10. The particle generation device according to claim 9, wherein the semiconductor material is CVD diamond.

11. The particle generation device according to claim 1, wherein the first enrichment surface is provided as a coating on the anode structure or the cathode structure.

12. The particle generation device according to claim 1, wherein the first enrichment surface is integrally formed with an electrode that forms at least a part of the surface.

13. The particle generation device according to claim 1, wherein the device is configured to generate nucleons during operation.

14. The particle generation device according to claim 13, wherein the nucleons are neutrons.

15. The particle generation device according to claim 13, wherein the nucleons are protons.

16. The particle generation device according to claim 15, wherein the device further comprises a fluid conduction structure proximate to the anode structure.

17. The particle generation device according to claim 16, wherein the fluid conduction structure is made of a metal alloy.

18. The particle generation device according to claim 16, wherein the fluid conduction structure includes a waveform along the length of the fluid conduction structure.

19. The particle generation device according to claim 1, wherein the first enrichment surface covers a part of the surface area of the anode structure or the cathode structure during operation such that the generated particles have a local flow rate with a predetermined geometric shape.

20. The particle generation device according to claim 1, wherein the first enrichment surface is at least a part of the surface of the anode structure, the second enrichment surface is at least a part of the surface of the cathode structure, and the second enrichment surface is enriched with fusible isotope species.

21. The particle generation device according to any one of claims 1 to 20, wherein the enrichment surface is enriched with deuterium and / or tritium by electrolysis with a deuterated and / or tritiated aqueous solution containing a conductive salt for electrolysis.

22. A system comprising a plurality of particle generation devices, wherein at least one particle generation device is the particle generation device according to claim 1, and a single power source is configured to supply power to several particle generation devices.

23. A system comprising a plurality of particle generation devices, wherein each of the plurality of particle generation devices is the particle generation device according to claim 1, and each of the plurality of particle generation devices is arranged in parallel such that the inner anode surface faces the irradiation region, and a part of the surface area of the anode facing the irradiation region is enriched, so that during operation, the generated particles have a local flow rate with a predetermined geometric shape.

24. A positron emission tomography (PET) scanner comprising the particle generation device according to claim 15.

25. Use of the particle generation device according to claim 15 as a proton generator for producing a PET medical radioisotope.

26. Use of the particle generation device according to claim 14 as a neutron generator, (i) for diagnostic and imaging or neutron activation applications, or (ii) pulsed mode neutrons for the detection of explosives and fissile materials, for use in any of these.

27. A method for manufacturing the particle generation device according to claim 1, comprising: providing the inertial electrostatic confinement type particle generation device, wherein the particle generation device comprises a container, an anode structure, and a cathode structure, the container includes a central axis, the anode structure and the cathode structure are arranged so as to be substantially coaxial with the container, the anode structure has an average distance from the central axis that is greater than the average radius from the central axis of the cathode structure, the anode structure and the cathode structure are substantially concentric along at least a part of the lengths of the anode structure and the cathode structure, and during operation, an electric field is provided between the anode structure and the cathode structure, providing the inertial electrostatic confinement type particle generation device; and concentrating deuterium and / or tritium on at least a part of the surface of the anode structure or the surface of the cathode structure by electrolysis with deuterated and / or tritiated water.

28. The step of concentrating deuterium and / or tritium on at least a part of the surface of the anode structure or the surface of the cathode structure comprises (i) filling the container with a deuterated and / or tritiated aqueous solution containing a conductive salt for electrolysis, (ii) inserting another cathode, and (iii) applying a voltage to form a hydride on the concentrated surface. The manufacturing method according to claim 27, comprising these steps.

29. The manufacturing method according to claim 27 or claim 28, wherein chemical etching of the surface to be concentrated is performed before the concentrating step.

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