A device for generating fusion reactor-level plasma off-target.
By using a linear magnetic field confinement device and a plasma generator, the problem of divertor target plate overload was solved, enabling fusion reactor-level plasma de-target operation, supporting refined research on material irradiation damage, and reducing experimental costs.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- MATERIAL INST OF CHINA ACADEMY OF ENG PHYSICS
- Filing Date
- 2026-04-21
- Publication Date
- 2026-07-14
Smart Images
Figure CN122393025A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of fusion reactor divertor plasma-material interaction testing technology, specifically to a device for generating fusion reactor-level plasma off-target. Background Technology
[0002] Currently, the mainstream magnetic confinement fusion device is the tokamak. In the tokamak, the divertor configuration, guided by boundary magnetic field lines, can reduce the interaction between the plasma and the first wall material, thereby reducing metallic impurities and improving the energy confinement of the core. However, most of the boundary plasma is guided into the divertor, causing the divertor to bear the majority of the particle and heat loss during fusion, resulting in a significant increase in the load on the divertor target plate. In future fusion reactors operating at high power deuterium-tritium, the load on the divertor will exceed the design limit of the target plate (10 MWm). -2 Even tungsten would find it difficult to withstand such high heat loads. Excessive heat load will increase the sputtering of heavy metal impurities like tungsten, and may even cause melting and cooling water leakage. Therefore, it is necessary to implement measures to mitigate the heat load on the divertor target plate. Divertor off-target operation is currently the only mitigation method, and major tokamak fusion research institutions around the world are conducting related research, mainly through the injection of impurities such as nitrogen, argon, and neon. However, the main research focuses on the impact of impurity injection and divertor off-target operation on plasma discharge, with very little research on material irradiation damage and deuterium-tritium cycling.
[0003] Under fusion reactor operating conditions, research on material irradiation damage and deuterium-tritium cycles requires equipment with precise control capabilities to scan parameters such as plasma beam density, heat load, and service time. This data is crucial for predicting material performance and supporting long-term steady-state operation of the fusion reactor. However, current tokamak research focuses on plasma physics, leaving very limited time for materials development. Plasma parameters are often difficult to control and diagnose precisely, and materials within the vacuum chamber, such as divertor materials, are difficult to remove or replace. Therefore, research on materials and deuterium-tritium cycles based on tokamak technology is extremely challenging and may lag far behind plasma physics, thus hindering the overall progress of fusion reactor projects. Therefore, developing laboratory-level condition simulation methods is essential.
[0004] Divertor plasma encompasses two main categories: the sputtering effect of the particle stream and the plasma thermal load. Existing continuous or pulsed laser technology and electron gun technology can generate MWm. -2 Even GWm -2The high-temperature load tests the cracking and cyclic thermal load capacity of tungsten alloy materials and components, but cannot investigate particle flow effects. Pulsed capacitor discharge techniques such as plasma guns can generate plasmas with high thermal loads, but these are pulsed processes dominated by surface melting and recrystallization, unlike the steady-state situation of target misses. Currently, using multi-spindle coils to generate linear magnetic fields, as opposed to the helical magnetic field configuration of Tokamak, is called a "linear device," which can generate steady-state low-temperature plasma and can be used to simulate the steady-state process of boundary plasmas. Currently, there is no scheme to achieve high-current target miss plasma using linear devices. Summary of the Invention
[0005] To address the aforementioned problems, the present invention aims to provide a device for generating fusion reactor-level plasma for target avoidance. This device generates divertor plasma beam density and heat load at the fusion reactor level by setting up a plasma generator, and utilizes the inherent characteristics of plasma through various impurity introduction methods to achieve plasma target avoidance conditions.
[0006] The technical solution adopted in this invention is as follows: A device for generating fusion reactor-level plasma off-target includes a linear magnetic field confinement device and a plasma generating device mounted on the linear magnetic field confinement device. The plasma generating device includes a flange and an anode seat spaced apart from the flange. A discharge chamber is provided in the anode seat, and a discharge electrode extending into the discharge chamber is provided on the anode seat. The anode seat is connected to a first air inlet pipe. An air inlet chamber is provided in the flange, and a second air inlet pipe connected to the air inlet chamber is provided on the flange. An air jet hole connected to the air inlet chamber is provided on the side wall of the nozzle. A suspended anode assembly is provided between the flange and the anode seat, and a discharge channel connected to the discharge chamber and the nozzle is provided in the suspended anode assembly.
[0007] Preferably, the suspended anode assembly includes an inner ring plate, a first annular groove is formed on the outer side of the inner ring plate, an outer ring plate is fitted on the outer side of the inner ring plate, and at least two first circulation pipes communicating with the annular groove are provided on the outer ring plate.
[0008] Preferably, the suspended anode assembly is provided with a partition assembly on both sides, the partition assembly includes a first annular partition, a second annular partition is sleeved on the outside of the first annular partition, and a sealing ring is provided between the first annular partition and the second annular partition.
[0009] Preferably, the first annular partition is a ceramic partition, and the second annular partition is an organic partition.
[0010] Preferably, a second annular groove is provided on the outer side of the anode seat, a clamping ring for sealing the second annular groove is fixedly sleeved on the outer side of the anode seat, and at least two second circulation pipes communicating with the second annular groove are provided on the anode seat.
[0011] Preferably, a screw is fixedly installed on the flange, the screw movably passes through the clamping ring and is threadedly connected to a nut.
[0012] Preferably, the flange is provided with a cooling chamber, and the flange is connected to at least two third circulation pipes communicating with the cooling chamber.
[0013] Preferably, the nozzle is provided with a nozzle that communicates with the discharge channel.
[0014] Preferably, the linear magnetic field confinement device includes a vacuum chamber, an opening aligned with the nozzle on one side of the vacuum chamber, several magnetic field coils on the outside of the vacuum chamber, a Roots pump assembly connected to the vacuum chamber, and a movable sample stage opposite to the opening inside the vacuum chamber. The movable sample stage is connected to a bias power supply line and a cooling water circulation pipe.
[0015] Preferably, the vacuum chamber is provided with a diagnostic window.
[0016] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are: By setting up a plasma generator to produce divertor plasma beam density and heat load at the fusion reactor level, and by introducing various impurities, the plasma's own characteristics are utilized to achieve plasma off-target conditions. Attached Figure Description
[0017] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.
[0018] Figure 1 This is a schematic diagram of the overall structure provided for an embodiment of the present invention; Figure 2 This is a three-dimensional structural diagram of a plasma generator provided in an embodiment of the present invention; Figure 3 This is a three-dimensional structural schematic diagram of the plasma generating device provided in an embodiment of the present invention from another perspective; Figure 4 This is a cross-sectional structural diagram of a plasma generator provided in an embodiment of the present invention.
[0019] Reference numerals: 1-Plasma generator; 101-Flange; 102-First circulation pipe; 103-Pressure ring; 104-Discharge electrode; 105-First inlet pipe; 106-Second circulation pipe; 107-Third circulation pipe; 108-Anode seat; 109-Nut; 110-Screw; 111-Second inlet pipe; 112-Jet hole; 113-Nozzle; 114-Nose; 115-Sealing ring; 116-Outer ring plate; 117 - Second annular partition; 118- First annular groove; 119- Inner annular plate; 120- First annular partition; 121- Second annular groove; 122- Discharge chamber; 123- Cooling chamber; 124- Inlet chamber; 2- Linear magnetic field confinement device; 201- Opening; 202- Moving sample stage; 203- Magnetic field coil; 204- Diagnostic window; 205- Cooling water circulation pipe; 206- Bias power supply line; 207- Roots pump set; 208- Vacuum chamber. Detailed Implementation
[0020] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.
[0021] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.
[0022] In the description of this invention, it should be noted that if terms such as "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," or "outer" are used to indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product is in use, they are only for the convenience of describing this invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.
[0023] The following is combined Figures 1-4 The present invention will be described in detail below.
[0024] Example: A device for generating fusion reactor-level plasma off-target includes a linear magnetic field confinement device 2 and a plasma generating device 1 mounted on the linear magnetic field confinement device 2. The plasma generating device 1 includes a flange 101 and an anode seat 108 spaced apart from the flange 101. A discharge chamber 122 is provided in the anode seat 108, and a discharge electrode 104 extending into the discharge chamber 122 is provided on the anode seat 108. A first air inlet pipe 105 is connected to the anode seat 108. An air inlet chamber 124 is provided in the flange 101, and a second air inlet pipe 111 connected to the air inlet chamber 124 is provided on the flange 101. A jet hole 112 connected to the air inlet chamber 124 is provided on the side wall of the nozzle 114. A suspended anode assembly is provided between the flange 101 and the anode seat 108, and a discharge channel connected to the discharge chamber 122 and the nozzle 114 is provided in the suspended anode assembly.
[0025] By setting up a plasma generator 1 to generate divertor plasma beam density and heat load at the fusion reactor level, and by introducing various impurities, the plasma's inherent characteristics are utilized to achieve plasma target avoidance conditions. Specifically, the plasma generator 1 produces high-density hydrogen / deuterium plasma. Based on high-current hydrogen isotope plasma doping, a linear magnetic field confinement device 2 is used to create an irradiation simulation condition where the target plasma interacts with the target plate. This application utilizes a laboratory device to generate fusion reactor-level boundary plasma, further achieving plasma target avoidance.
[0026] Both the first intake pipe 105 and the second intake pipe 111 are connected to a mass flow controller (not shown in the figure) to control the gas flow rate. The discharge channel is a circular hole, the diameter of which is determined by the discharge gas and power and can be adjusted between (2-10) mm. The suspended anode assembly can control the gas pressure in the cathode discharge chamber 122 to form an atmospheric pressure discharge, and can also confine the plasma generated by the gas discharge to prevent it from being too diffuse. The discharge electrode 104 is made of a high-temperature resistant material with high thermionic emission efficiency, such as pure tungsten or a tungsten-thorium alloy.
[0027] The key to off-target plasma lies in controlling the partial pressure and type of neutral gas in the background. This application uses a first inlet pipe 105 to pre-mix impurity gas into hydrogen isotope gas, and a second inlet pipe 111 to replenish hydrogen isotope gas or impurity gases such as nitrogen and neon. The gas output from the second inlet pipe 111 enters the nozzle 114 through the jet hole 112 to mix with the plasma. Utilizing the higher electron temperature of the plasma at this location, further ionization is achieved to form a mixed gas plasma. Several jet holes 112 are evenly arranged circumferentially along the nozzle 114 to uniformly output impurity gas.
[0028] This application utilizes atmospheric pressure arc discharge to generate ultra-high density plasma, with the plasma density ejected from nozzle 114 reaching 10. 21m -3 The magnitude is (5-10) eV, and the plasma beam density at the divertor reaches the discharge power of a fusion reactor. In addition to directly mixing in the impurity gas, a new injection method is added to simulate the transport of boundary plasma into the neutral background of the divertor, which will be different from the plasma characteristics transported by the mixed discharge in discharge chamber 122.
[0029] The suspended anode assembly includes an inner ring plate 119, with a first annular groove 118 formed on the outer side of the inner ring plate 119. An outer ring plate 116 is fitted around the outer side of the inner ring plate 119, and at least two first circulation pipes 102 communicating with the annular groove 118 are provided on the outer ring plate 116. The inner ring plate 119 and the outer ring plate 116 cooperate to enclose the first annular groove 118 into a closed chamber. Circulating cooling water is supplied to the first annular groove 118 through the first circulation pipes 102, thereby cooling the suspended anode assembly and ensuring that the suspended anode assembly is not melted or ablated during long-term stable operation. The number of suspended anode assemblies can be selected according to requirements.
[0030] The suspended anode assembly has baffle assemblies on both sides. Each baffle assembly includes a first annular baffle 120, and a second annular baffle 117 is fitted around the outside of the first annular baffle 120. A sealing ring 115 is provided between the first annular baffle 120 and the second annular baffle 117. The baffle assemblies provide insulation between the suspended anode assembly and the anode seat 108, between suspended anode assemblies, and between the suspended anode assembly and the flange 101, with a withstand voltage greater than 5 kV. Preferably, the first annular baffle 120 is a ceramic baffle, which can withstand high temperatures and is therefore located on the inner side. The second annular baffle 117 is an organic baffle. Organic baffles reduce operating costs compared to ceramic baffles. Furthermore, organic baffles are softer and have a certain degree of elasticity, serving as a shock-absorbing structure for ceramic baffles and preventing easy damage to them. The sealing ring 115 seals the gaps between the suspended anode assembly and the anode seat 108, between the suspended anode assemblies, and between the suspended anode assembly and the flange 101, ensuring that air does not enter the discharge chamber 122 or that discharge gas does not leak into the environment. Preferably, the sealing ring 115 is an O-ring.
[0031] A second annular groove 121 is provided on the outer side of the anode seat 108. A clamping ring 103 for sealing the second annular groove 121 is fixedly sleeved on the outer side of the anode seat 108. At least two second circulation pipes 106 communicating with the second annular groove 121 are provided on the anode seat 108. The anode seat 108 and the clamping ring 103 cooperate to form a closed chamber around the second annular groove 121. Circulating cooling water is delivered to the second annular groove 121 through the second circulation pipes 106, thereby cooling the anode seat 108 and ensuring that the anode seat 108 is not melted or burned during long-term stable operation.
[0032] A screw 110 is fixedly mounted on flange 101, and the screw 110 movably passes through clamping ring 103 and is threadedly connected to nut 109. Tightening nut 109 causes anode seat 108 and flange 101 to cooperate and clamp the suspended anode assembly, thereby completing the installation of anode seat 108, suspended anode assembly, and flange 101. A T-shaped insulating sleeve is provided between screw 110 and clamping ring 103, which also prevents contact between nut 109 and clamping ring 103.
[0033] The flange 101 is provided with a cooling chamber 123, and the flange 101 is connected to at least two third circulation pipes 107 that communicate with the cooling chamber 123. Cooling water is circulated into the cooling chamber 123 through the third circulation pipes 107 to cool the flange 101 and ensure that the flange 101 is not melted or burned during long-term stable operation.
[0034] A baffle is provided in the first annular groove 118, which separates the openings of the two first circulation pipes 102, so that the coolant output from one of the first circulation pipes 102 can flow almost a full circle along the first annular groove 118 and then return to the other first circulation pipe 102, thereby achieving circulating cooling. Similarly, corresponding baffles are also provided in the second annular groove 121 and the cooling chamber 123 to achieve circulating cooling.
[0035] The nozzle 114 is provided with a nozzle 113 that communicates with the discharge channel. The nozzle 113 can converge the plasma output from the discharge channel, causing the plasma to accelerate and move in a directional manner.
[0036] The linear magnetic field confinement device 2 includes a vacuum chamber 208. An opening 201 aligned with the nozzle 114 is provided on one side of the vacuum chamber 208. Several magnetic field coils 203 are provided on the outside of the vacuum chamber 208. A Roots pump assembly 207 is connected to the vacuum chamber 208. A movable sample stage 202 opposite to the opening 201 is provided in the vacuum chamber 208. The movable sample stage 202 is connected to a bias power supply line 206 and a cooling water circulation pipe 205.
[0037] One end of the vacuum chamber 208 is connected to the plasma generator 1, and the other end is connected to the Roots pump assembly 207. Utilizing the high pumping speed of the Roots pump in the Pa-level vacuum, a Pa-level background vacuum can be maintained over a wide range of inlet rates, consistent with the pressure of the fusion reactor divertor. This application employs three magnetic field coils 203 to form a horizontal magnetic field. To ensure the spatial uniformity of the magnetic field and reduce ripple, especially in the central confinement plasma region, the magnetic field coils 203 adopt an irregular shape, i.e., as shown... Figure 1 As shown, the central magnetic field coil 203 has a different size than the magnetic field coils 203 on both sides. The sample to be irradiated is placed on the moving sample stage 202 near the center of the plasma surface. The moving sample stage 202 is connected to a cooling water circulation pipe 205 to circulate cooling water, preventing the sample from melting under high heat load and creating a temperature gradient similar to that of a divertor component under plasma irradiation. The moving sample stage 202 is insulated from the vacuum chamber 208, typically using ceramic gaskets. It is connected to a bias power supply via a bias power line 206 to apply a negative bias voltage, which is used to control the energy of the ions bombarding the target plate. The bias power supply with automatic voltage scanning function can also measure the ion saturation current of the plasma, allowing estimation of the plasma beam density.
[0038] The movable sample stage 202 is existing technology. Its position can be adjusted to adjust the distance between the movable sample stage 202 and the plasma generator 1. The distance between the movable sample stage 202 and the plasma generator 1 is adjustable and serves as a variable to change the plasma parameters. The adjustment range is (5-30) cm, which is used to generate plasma with different degrees of off-target, and to simulate the plasma irradiation conditions at different positions under the divertor irregular structure.
[0039] By changing the inlet rate or discharge power of the cascaded arc, the plasma can be made to operate in the ionization region, the recombination region, or the transition region between the two. When operating in the ionization region, the electron temperature is high, approaching 10 eV, which can secondary ionize the impurity gas. By adjusting the degree of interaction between the plasma and the impurity gas—primarily by adjusting the distance between the nozzle 114 and the target plate and adjusting the background pressure—the degree of target miss can be controlled. When operating in the recombination region, the impurity gas can be mixed and transported to the first inlet pipe 105 to directly form a target miss plasma.
[0040] A diagnostic window 204 is provided on the vacuum chamber 208, which is used to measure the characteristic evolution of the plasma at the front end of the target plate.
[0041] It should be noted that the purpose of plasma de-targeting is to reduce the load on the plasma-facing components. The main method is to inject low-to-medium Z impurities, such as N2 and Ne, into the divertor location. The plasma reduces the particle density and energy bombarding the target plate through collisions and recombination, and further dissipates the heat load reaching the target plate through radiation, thereby reducing recombination on the target plate. From the visual measurement of plasma density, temperature, and radiation profile, the plasma appears to have "detached" from the target plate; this is called "plasma de-targeting."
[0042] Advantages of this application: (1) It can realize the plasma conditions of fusion reactor level. Existing tokamak devices are in the physical experiment stage. Although some devices can carry out plasma discharge off-target, the discharge power is 1 to 2 orders of magnitude lower than that of fusion reactor. The ion beam density and heat load of the boundary material cannot reach the level of fusion reactor, so it is impossible to truly evaluate the divertor material.
[0043] (2) It enables refined research. Existing tokamak devices have short discharge times, only on the order of seconds, and the discharge parameters cannot be accurately monitored and controlled, making it difficult to extract and analyze materials placed in the vacuum chamber in real time. Based on the linear device, the discharge is a steady-state discharge, and the discharge time can be maintained for tens of hours or more, allowing for continuous irradiation testing of materials, thus achieving accelerated testing and screening of materials. The parameters of steady-state plasma are easy to diagnose, and the plasma beam density, heat load, temperature, etc., can be flexibly adjusted by parameters such as discharge power, gas inlet rate, magnetic field, bias voltage, and spatial configuration, enabling refined research on plasma physics and material irradiation damage.
[0044] (3) Compared with technologies such as tokamak, electron gun, and pulsed plasma gun, this application significantly reduces the experimental cost. It provides an invaluable experimental means for the material testing needs of future fusion reactors, greatly reducing the cost and risk of testing materials on fusion reactor test reactors such as ITER.
[0045] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.
Claims
1. A device for generating fusion reactor-level plasma off-target, characterized in that, The device includes a linear magnetic field confinement device (2) and a plasma generator (1) installed on the linear magnetic field confinement device (2). The plasma generator (1) includes a flange (101) and an anode seat (108) spaced apart from the flange (101). A discharge chamber (122) is provided in the anode seat (108). A discharge electrode (104) extending into the discharge chamber (122) is provided on the anode seat (108). A first air inlet pipe (105) is connected to the anode seat (108). An air inlet chamber (124) is provided in the flange (101). A second air inlet pipe (111) connected to the air inlet chamber (124) is provided on the flange (101). A jet hole (112) connected to the air inlet chamber (124) is provided on the side wall of the nozzle (114). A suspended anode assembly is provided between the flange (101) and the anode seat (108). A discharge channel connected to the discharge chamber (122) and the nozzle (114) is provided in the suspended anode assembly.
2. The device for generating fusion reactor-level plasma off-target according to claim 1, characterized in that, The suspended anode assembly includes an inner ring plate (119), a first annular groove (118) is provided on the outer side of the inner ring plate (119), an outer ring plate (116) is sleeved on the outer side of the inner ring plate (119), and at least two first circulation pipes (102) connected to the annular groove (118) are provided on the outer ring plate (116).
3. The device for generating fusion reactor-level plasma off-target according to claim 1, characterized in that, The suspended anode assembly is provided with a partition assembly on both sides. The partition assembly includes a first annular partition (120), a second annular partition (117) is sleeved on the outside of the first annular partition (120), and a sealing ring (115) is provided between the first annular partition (120) and the second annular partition (117).
4. The device for generating fusion reactor-level plasma off-target according to claim 3, characterized in that, The first annular partition (120) is a ceramic partition, and the second annular partition (117) is an organic partition.
5. The device for generating fusion reactor-level plasma off-target according to claim 1, characterized in that, The anode seat (108) is provided with a second annular groove (121) on the outside. A clamping ring (103) for sealing the second annular groove (121) is fixedly sleeved on the outside of the anode seat (108). At least two second circulation pipes (106) connected to the second annular groove (121) are provided on the anode seat (108).
6. The apparatus for generating fusion reactor-level plasma off-target according to claim 5, characterized in that, A screw (110) is fixedly installed on the flange (101). The screw (110) moves through the clamping ring (103) and is threadedly connected to a nut (109).
7. The device for generating fusion reactor-level plasma off-target according to claim 1, characterized in that, The flange (101) is provided with a cooling chamber (123), and the flange (101) is connected to at least two third circulation pipes (107) that communicate with the cooling chamber (123).
8. The device for generating fusion reactor-level plasma off-target according to claim 1, characterized in that, The nozzle (113) is provided in the nozzle (114) and is connected to the discharge channel.
9. The device for generating fusion reactor-level plasma off-target according to claim 1, characterized in that, The linear magnetic field confinement device (2) includes a vacuum chamber (208), an opening (201) aligned with the nozzle (114) is provided on one side of the vacuum chamber (208), several magnetic field coils (203) are provided on the outside of the vacuum chamber (208), a Roots pump group (207) is connected to the vacuum chamber (208), and a movable sample stage (202) opposite to the opening (201) is provided in the vacuum chamber (208). The movable sample stage (202) is connected to a bias power supply line (206) and a cooling water circulation pipe (205).
10. The apparatus for generating fusion reactor-level plasma off-target according to claim 9, characterized in that, The vacuum chamber (208) is provided with a diagnostic window (204).