Diagnostic method and system for measuring potential and electric field of plasma

Abstract

The present invention relates to the technical field of neutral beam probe measurement, and provides a diagnostic method and system for measuring the potential and electric field of plasma. The method comprises: on the basis of acquired operation parameters of a magnetic confinement fusion apparatus and related parameter data of candidate particle elements, calculating signal-to-noise ratios; on the basis of the signal-to-noise ratios, selecting a neutral beam particle element, and iteratively calculating beam current trajectories of different incident energy, incident angles, and sampling areas to obtain preset parameters that enable a beam trajectory to pass through an entrance slit of an analyzer; injecting a neutral beam meeting preset parameter requirements into plasma; using the analyzer to measure primary ion beam energy of the neutral beam generated by collision ionization in a sampling area, and, on the basis of the law of conservation of energy, obtaining the potential of the sampling area; and testing different sampling areas to obtain a spatial distribution of the plasma potential and a radial electric field, so that the diagnostic ends. The beneficial effect of the present invention is that the method has extremely important significance for in-depth research of the physical mechanisms of the radial electric field and Er×B shear flow in magnetic confinement fusion plasma for suppressing turbulence and improving confinement.

Description

A diagnostic method and system for measuring plasma potential and electric field Technical Field

[0001] The present invention relates to the field of neutral beam probe measurement technology, and in particular to a diagnostic method and system for measuring plasma potential and electric field. Background Art

[0002] Radial Electric Field in Magnetic Confinement Fusion Plasma and Flow shear is extremely important for suppressing plasma turbulent transport and improving confinement. Currently, only the Heavy Ion Beam Probe (HIBP) can achieve the plasma potential ( ) and radial electric field ( HIBP is widely used in fusion devices because it allows for high temporal and spatial resolution measurements. The principle of HIBP is to measure the energy of the secondary ion beam generated by the collision ionization of a singly charged ion beam with electrons in the plasma, thereby determining the local electric potential (field) and its fluctuations in the ionized region (i.e., the sampling area). This method is only applicable to plasmas with relatively high temperatures and densities. HIBP is difficult to apply to plasmas with low parameters. Technical issues

[0003] The object of the present invention is to provide a diagnostic method and system for measuring plasma potential and electric field to improve the above problems. Technical Solutions

[0004] In order to achieve the above object, the technical solution adopted by the present invention is as follows:

[0005] In a first aspect, the present application provides a diagnostic method for measuring plasma potential and electric field, comprising:

[0006] Based on the acquired operating parameters of the magnetic confinement fusion device, several elements are selected as candidate particle elements to obtain relevant parameter data, wherein the relevant parameter data includes particle mass data, primary impact ionization cross section data, and secondary impact ionization cross section data, wherein the operating parameters include the background magnetic field of the magnetic confinement fusion device, the electron temperature of the plasma, and the electron density of the plasma;

[0007] Based on the operating parameters and related parameter data, the particle beam trajectory and the effective collision ionization cross section data between the particle and the electron are calculated, and then the signal-to-noise ratio of the candidate particle element is calculated. According to the signal-to-noise ratio, the appropriate element is selected as the neutral beam particle element used for diagnosis;

[0008] Based on the particle mass data of the neutral beam particle elements, the preset parameters of the particle beam trajectory that can pass through the analyzer entrance slit are obtained by iterative calculation, wherein the preset parameters include the incident energy, the incident angle, and the sampling area;

[0009] Based on the neutral beam particle element, a solid-state thermal ion source is used to heat and generate ions, and the ions are accelerated using a Pierce electrode device to obtain a directed ion beam. The directed ion beam is then exchanged with a preset neutral gas charge to generate a neutral beam with a preset incident energy. Based on preset parameters, the neutral beam is injected into the plasma at a preset incident angle.

[0010] The primary ion beam generated by the collision ionization of the neutral beam in the sampling area is analyzed and calculated using an analyzer to obtain the energy of the primary ion beam. Based on the energy difference between the primary ion beam and the neutral beam, the potential of the sampling area is obtained according to the law of conservation of energy. The above steps are repeated to collect the energy of the primary ion beams generated in different sampling areas, and the spatial distribution of the plasma potential at different radial positions and the radial electric field are obtained, thereby completing the diagnosis.

[0011] Preferably, the particle beam trajectory is calculated based on the operating parameters and related parameter data, including:

[0012] Based on the particle mass data, a neutral beam of a candidate particle element is injected into the plasma at a certain incident velocity and angle. It collides with electrons in the plasma to produce a primary ion beam. The primary ion beam is deflected by the background magnetic field and passes through the plasma. The particle beam trajectory is calculated as follows:

[0013]

[0014] Where, is the beam trajectory, is the differential symbol, for The differential of For time, is the differential of t, is the incident velocity of the neutral beam, is the particle mass of the candidate particle element, is the charge (neutral beam , primary ion beam , is the electron charge), is the background magnetic field, and the particle's speed along the beam trajectory is Basically unchanged, that is , for other candidate particle elements of the neutral beam, under the same beam trajectory, the incident velocity It can be converted based on the same Larmor radius: ,in is the particle mass of other candidate particle elements.

[0015] Preferably, the particle beam trajectory and effective collision ionization cross section data between particles and electrons are calculated based on the operating parameters and related parameter data, and then the signal-to-noise ratio of the candidate particle element is calculated, and a suitable element is selected as the neutral beam particle element used for the diagnosis according to the signal-to-noise ratio, which also includes:

[0016] Based on the Maxwell rate distribution function, the primary impact ionization cross section data, and the secondary impact ionization cross section data, the effective impact ionization cross section data between particles and electrons is obtained. The calculation formula is as follows:

[0017]

[0018] Where, , is the relative velocity of the particle and the electron, is the particle speed, is the electron speed, is the differential symbol, for The differential of is the Maxwell rate distribution function, is the plasma electron temperature, is the electron mass, is the Boltzmann constant, is the impact ionization cross section, is the effective impact ionization cross section, and the single impact ionization cross section is substituted Obtain an effective collision ionization cross section data , bringing in the secondary impact ionization cross section Secondary effective impact ionization cross section ;

[0019] The signal-to-noise ratio of the candidate particle element is calculated based on the operating parameters, related parameter data, beam trajectory, and effective collision ionization cross-section data. The calculation formula is as follows:

[0020]

[0021] Where, is the signal-to-noise ratio, is the electron density of the plasma, is the entrance slit width, is the differential symbol, for The differential of is the beam trajectory, It is the time for the neutral beam to reach the plasma core and generate a primary ion beam by impact ionization. is the time it takes for the primary ion beam to pass through the plasma, 、 are the primary and secondary effective collision ionization cross sections, respectively;

[0022] According to the signal-to-noise ratio of the candidate particle elements, select The elements are used as the neutral beam particle elements for this diagnosis.

[0023] Preferably, the particle mass data based on the neutral beam particle elements are iteratively calculated to obtain preset parameters for the particle beam trajectory to pass through the analyzer entrance slit, wherein the preset parameters include incident energy, incident angle, and sampling area, including:

[0024] The beam trajectory is calculated to obtain beam trajectories at different incident velocities, incident angles, and sampling areas, wherein the beam trajectory includes the trajectory of the neutral beam reaching the sampling area and the trajectory of the primary ion beam generated after impact ionization;

[0025] The beam trajectory is iteratively calculated to obtain preset parameter information corresponding to the beam trajectory that enables the primary ion beam to pass through the analyzer entrance slit, wherein the preset parameter information includes the neutral beam incident energy, incident angle and sampling area.

[0026] Preferably, the neutral beam particle element is based on generating ions by heating with a solid-state thermal ion source, accelerating the ions by a Pierce electrode device to obtain a directed ion beam, and generating a neutral beam by exchanging charges between the directed ion beam and a preset neutral gas, which includes:

[0027] A solid-state thermal ion source corresponding to the neutral beam particle element is selected and heated to overflow ions. The overflowing ions are accelerated using a Pierce electrode device and focused under the action of an electrostatic lens to obtain a directional ion beam.

[0028] A directed ion beam is introduced into a neutralization chamber device, and a neutral beam with a preset incident energy is generated by exchanging charges with a preset neutral gas, and the neutral beam is injected into the plasma at a preset incident angle.

[0029] Preferably, the analyzer is used to analyze and calculate the primary ion beam generated by the collision ionization of the neutral beam in the sampling area to obtain the energy of the primary ion beam; based on the energy difference between the primary ion beam and the neutral beam, the potential of the sampling area is obtained according to the law of conservation of energy, which includes:

[0030] The primary ion beam generated by the collision ionization of the neutral beam in the sampling area is analyzed and calculated by using an analyzer to obtain the energy of the primary ion beam;

[0031] Based on the energy difference between the primary ion beam and the neutral beam, the potential of the sampling area is obtained according to the law of conservation of energy, which is calculated as follows:

[0032]

[0033] in, is the potential of the sampling area, is the primary ion beam energy, is the incident energy of the neutral beam, is the charge of the electron.

[0034] In a second aspect, the present application further provides a diagnostic system for measuring plasma potential and electric field, comprising a first acquisition module, a first calculation module, a second calculation module, a third calculation module, and a second acquisition module, wherein:

[0035] A first acquisition module is configured to select several elements as candidate particle elements based on the acquired operating parameters of the magnetic confinement fusion device, and obtain relevant parameter data, wherein the relevant parameter data includes particle mass data, primary collision ionization cross section data, and secondary collision ionization cross section data, wherein the operating parameters include the background magnetic field of the magnetic confinement fusion device, the electron temperature of the plasma, and the electron density of the plasma;

[0036] The first calculation module is used to calculate the particle beam trajectory and the effective collision ionization cross section data between the particle and the electron based on the operating parameters and related parameter data, and then calculate the signal-to-noise ratio of the candidate particle element, and select the appropriate element as the neutral beam particle element used for diagnosis based on the signal-to-noise ratio;

[0037] A second calculation module is used for iteratively calculating, based on the particle mass data of the neutral beam particle elements, the preset parameters of the particle beam trajectory that can pass through the analyzer entrance slit, wherein the preset parameters include incident energy, incident angle, and sampling area;

[0038] The third calculation module is used to generate ions based on neutral beam particle elements by heating with a solid-state thermal ion source, accelerate the ions using a Pierce electrode device to obtain a directed ion beam, and generate a neutral beam with a preset incident energy by exchanging charges between the directed ion beam and a preset neutral gas; based on preset parameters, the neutral beam is injected into the plasma at a preset incident angle;

[0039] The second acquisition module is used to use the analyzer to analyze and calculate the primary ion beam generated by the collision ionization of the neutral beam in the sampling area to obtain the energy of the primary ion beam; based on the energy difference between the primary ion beam and the neutral beam, the potential of the sampling area is obtained according to the law of conservation of energy, and the above steps are repeated to collect the energy of the primary ion beams generated in different sampling areas, and the spatial distribution of the plasma potential at different radial positions and the radial electric field are obtained, and the diagnosis is completed. Beneficial effects

[0040] The beneficial effects of the present invention are:

[0041] The present invention proposes a neutral beam probe measurement technology. This diagnostic system uses a neutral beam to generate a primary ion beam through a single collision ionization with electrons in the plasma. By measuring the energy of the primary ion beam, the local electric potential (electric field) and its fluctuations in the sampling area are obtained. Based on the HIBP measurement principle commonly used in the core region of high-temperature plasmas, this technology proposes a neutral beam probe (NBP) measurement technology with low disturbance, high spatiotemporal resolution, and applicability to low-parameter plasmas. This technology is used to detect the plasma potential (electric field) and its fluctuations. Compared with traditional HIBP, this diagnostic system can still achieve a sufficient signal-to-noise ratio when the plasma parameters are low.

[0042] The NBP measurement technology proposed in this invention is mainly aimed at measuring the potential (electric field) and its fluctuations in plasmas with relatively low parameters. It is characterized by small disturbances and high spatiotemporal resolution. For plasmas with relatively low temperatures or low electron densities, a high signal-to-noise ratio can still be obtained. It should be pointed out that the measurement technology proposed in this invention is currently the only measurement method that can be used to directly measure the potential and electric field in low-parameter plasmas. It is of great significance to the in-depth study of the radial electric field and The physical mechanism by which flow shear suppresses turbulence and improves confinement is of great significance.

[0043] Other features and advantages of the present invention will be described in the following description, and in part will become apparent from the description, or understood by practicing the embodiments of the present invention. The purposes and other advantages of the present invention can be realized and obtained by the structures particularly pointed out in the written description, claims, and drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. It should be understood that the following drawings only illustrate certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without paying any creative work.

[0045] FIG1 is a schematic flow chart of a diagnostic method for measuring plasma potential and electric field according to an embodiment of the present invention;

[0046] FIG2 is a schematic diagram showing the basic working principle of the diagnostic method for measuring plasma potential and electric field according to an embodiment of the present invention;

[0047] FIG3 is a schematic diagram of the structure of an analyzer for the diagnostic method for measuring plasma potential and electric field according to an embodiment of the present invention;

[0048] FIG4 is a schematic structural diagram of a detection board for a diagnostic method for measuring plasma potential and electric field according to an embodiment of the present invention;

[0049] FIG5 is a system diagram of a diagnostic method for measuring plasma potential and electric field according to an embodiment of the present invention.

[0050] In the figure: 701, first acquisition module; 702, first calculation module; 7021, collision unit; 703, second calculation module; 7031, first calculation unit; 7032, second calculation unit; 7033, third calculation unit; 7034, fourth calculation unit; 7035, selection unit; 704, third calculation module; 7041, selection unit; 7042, focusing unit; 7043, exchange unit; 7044, fifth calculation unit; 705, second acquisition module. Best Mode for Carrying Out the Invention

[0051] The best mode for carrying out the present invention is the same as the embodiment of the present invention described below. Modes for Carrying Out the Invention

[0052] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. The components of the embodiments of the present invention generally described and shown in the drawings herein can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the claimed invention, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0053] It should be noted that similar reference numerals and letters represent similar items in the following drawings. Therefore, once an item is defined in one drawing, it does not need to be further defined or explained in subsequent drawings. At the same time, in the description of the present invention, the terms "first", "second", etc. are used only to distinguish the description and should not be understood as indicating or implying relative importance.

[0054] Example 1:

[0055] This embodiment provides a diagnostic method for measuring plasma potential and electric field.

[0056] 1 to 4 , the method includes steps S100 , S200 , S300 , S400 and S500 .

[0057] S100. Based on the acquired operating parameters of the magnetic confinement fusion device, several elements are selected as candidate particle elements to obtain relevant parameter data, wherein the relevant parameter data includes particle mass data, primary collision ionization cross section data, and secondary collision ionization cross section data, wherein the operating parameters include the background magnetic field of the magnetic confinement fusion device, the electron temperature of the plasma, and the electron density.

[0058] It is understood that in this step, according to the operating parameters of the magnetic confinement fusion device, the operating parameters include the background magnetic field of the device , plasma electron temperature and the electron density of the plasma , select several elements as candidate particle elements, usually sodium, potassium, rubidium, cesium, etc., and get the mass of the particle , single impact ionization cross section , secondary impact ionization cross section ,in is the relative velocity of the particle and the electron during collision.

[0059] S200. Based on the operating parameters and related parameter data, the particle beam trajectory and the effective collision ionization cross section data between the particle and the electron are calculated, and then the signal-to-noise ratio of the candidate particle element is calculated. According to the signal-to-noise ratio, a suitable element is selected as the neutral beam particle element used for the diagnosis.

[0060] It can be understood that the step S200 includes S201, S202, S203 and S204, wherein:

[0061] S201. Based on the particle mass data, a neutral beam of a candidate particle element is injected into the plasma at a certain incidence velocity and angle. The neutral beam collides with electrons in the plasma to generate a primary ion beam. The primary ion beam is deflected by the background magnetic field and passes through the plasma. The particle beam trajectory is calculated as follows:

[0062]

[0063] Where, is the beam trajectory, is the differential symbol, for The differential of For time, for The differential of is the incident velocity of the neutral beam, is the particle mass of the candidate particle element, is the charge (neutral beam , primary ion beam , is the electron charge), is the background magnetic field, and the particle's speed along the beam trajectory is Basically unchanged, that is , for other candidate particle elements of the neutral beam, under the same beam trajectory, the incident velocity It can be converted based on the same Larmor radius: ,in is the particle mass of other candidate particle elements.

[0064] It should be noted that, assuming the beam trajectory of a candidate particle element The neutral beam is incident at a certain speed The incident angle is injected into the plasma, and the collision ionization with the core electrons produces a primary ion beam. The primary ion beam is in the background magnetic field. Under the action of the plasma, it is deflected and passes through the plasma.

[0065] S202. Based on the Maxwell rate distribution function, the primary impact ionization cross section data, and the secondary impact ionization cross section data, obtain effective impact ionization cross section data between the particle and the electron. The calculation formula is as follows:

[0066]

[0067] Where, , is the relative velocity of the particle and the electron, is the particle speed, is the electron speed, is the differential symbol, for The differential of is the Maxwell rate distribution function, is the plasma electron temperature, is the electron mass, is the Boltzmann constant, is the impact ionization cross section, is the effective impact ionization cross section, and the single impact ionization cross section is substituted Get an effective impact ionization cross section , bringing in the secondary impact ionization cross section Secondary effective impact ionization cross section ;

[0068] S203. Calculate the signal-to-noise ratio of the candidate particle element based on the operating parameters, relevant parameter data, beam trajectory, and effective collision ionization cross-section data. The calculation formula is as follows:

[0069]

[0070] Where, is the signal-to-noise ratio, is the electron density of the plasma, is the entrance slit width, is the differential symbol, for The differential of is the beam trajectory, It is the time for the neutral beam to reach the plasma core and generate a primary ion beam by impact ionization. is the time it takes for the primary ion beam to pass through the plasma, 、 is the primary and secondary effective collision ionization cross sections;

[0071] S204, according to the signal-to-noise ratio of the candidate particle element, select The elements are used as the neutral beam particle elements for this diagnosis.

[0072] It should be noted that the calculation of signal-to-noise ratio , choose the signal-to-noise ratio as large as possible and The elements are used as neutral beam particles for this diagnosis.

[0073] S300. Based on the particle mass data of the neutral beam particle elements, iteratively calculate the preset parameters of the particle beam trajectory that can pass through the analyzer entrance slit, where the preset parameters include incident energy, incident angle, and sampling area.

[0074] It is understandable that the step S300 includes S301 and S302, wherein:

[0075] S301, calculating beam trajectories at different incident velocities, incident angles, and sampling areas based on beam trajectories, wherein the beam trajectories include trajectories of neutral beams reaching the sampling area and trajectories of primary ion beams generated after impact ionization;

[0076] S302 , iteratively calculating the beam trajectory to obtain preset parameter information corresponding to the beam trajectory for the primary ion beam to pass through the analyzer entrance slit, wherein the preset parameter information includes the neutral beam incident energy, incident angle, and sampling area.

[0077] It should be noted that according to the beam trajectory calculation formula, the beam trajectory is calculated at different incident speeds. The trajectory of the primary ion beam after collision ionization occurs at different positions along its trajectory, and the three preset parameters corresponding to the beam trajectory of the primary ion beam that can pass through the analyzer entrance slit are obtained through iteration: the neutral beam incident energy , incident angle, and the region of impact ionization (i.e., the sampling region) are defined. Specifically, a neutral beam injected at this preset incident energy and angle generates a primary ion beam in the sampling region along its trajectory that can enter the analyzer for collection. The calculated energy difference provides the potential of that sampling region. Using an iterative formula, the preset incident energy and angle are varied to determine the potential of another sampling region. This process is repeated to determine the spatial distribution of the plasma potential at different radial positions and the radial electric field.

[0078] S400, based on neutral beam particle elements, uses a solid-state thermal ion source to heat and generate ions, and uses a Pierce electrode device to accelerate the ions to obtain a directed ion beam, and generates a neutral beam with a preset incident energy by exchanging charges between the directed ion beam and a preset neutral gas; based on preset parameters, injects the neutral beam into the plasma at a preset incident angle.

[0079] It should be noted that after the neutral beam is ionized by collision in the plasma sampling region, a primary ion beam is generated, which then enters the analyzer. Therefore, the analyzer analyzes the primary ion beam in order to calculate the energy of the primary ion beam.

[0080] It can be understood that the step S400 includes S401 and S402, wherein:

[0081] S401, selecting a solid-state thermionic source corresponding to a neutral beam particle element and heating it to overflow ions, accelerating the overflowing ions using a Pierce electrode device, and focusing them under the action of an electrostatic lens to obtain a directional ion beam;

[0082] It should be noted that the solid state thermal ion source corresponding to the element is selected and heated to release ions. The ions are accelerated using a Pierce electrode device, and the electrode voltage is , and is focused by the electrostatic lens to form energy Directed ion beam.

[0083] S402, introducing the directed ion beam into the neutralization chamber equipment, generating a neutral beam of preset energy by exchanging charges with a preset neutral gas, and injecting the neutral beam into the plasma at a preset incident angle.

[0084] S500. Use an analyzer to analyze and calculate the primary ion beam generated by the collision ionization of the neutral beam in the sampling area to obtain the energy of the primary ion beam; based on the energy difference between the primary ion beam and the neutral beam, the potential of the sampling area is obtained according to the law of conservation of energy. Repeat the above steps to collect the energy of the primary ion beams generated in different sampling areas, and obtain the spatial distribution of the plasma potential at different radial positions and the radial electric field, thereby completing the diagnosis.

[0085] It is understandable that the step S500 includes S501 and S502, wherein:

[0086] S501, using an analyzer to analyze and calculate the primary ion beam generated by collision ionization of the neutral beam in the sampling area to obtain the energy of the primary ion beam;

[0087] S502. Based on the energy difference between the primary ion beam and the neutral beam, the potential of the sampling area is obtained. The calculation method is as follows:

[0088]

[0089] in, is the potential of the sampling area, is the primary ion beam energy, is the incident energy of the neutral beam, is the charge of the electron.

[0090] It should be noted that the neutral beam undergoes collision ionization in the sampling area to produce a primary ion beam, which is The primary ion beam is deflected by the action and passes through the plasma and enters the analyzer, which is placed outside the magnetic confinement fusion device in a non-magnetic area. After passing through the entrance slit of the analyzer, the primary ion beam enters the parallel capacitor and flows to the detection plate (divided into four parts, upper, lower, left and right) under the action of the electric field. The anode voltage of the parallel capacitor is adjusted by the program control software. , so that all four detection plates can collect the primary ion beam, and the current intensity of the upper and lower plates are and .in, is the upper left plate current, is the current on the upper right plate, is the current of the lower left plate, is the current of the lower right plate.

[0091] By calculating the current difference ratio between the upper and lower plates, the center position of the beam landing point on the detection plate is obtained. , and obtain the primary ion beam energy :

[0092]

[0093] in, 、 are the upper and lower plate current intensities, is the entrance slit width;

[0094]

[0095] in, 、 are the vertical heights from the entrance slit and the center of the detection plate to the lower plate of the parallel capacitor, is the horizontal distance from the entrance slit to the center of the detection plate, is the distance between the upper and lower plates of the parallel capacitor, is the horizontal angle of the primary ion beam when it passes through the entrance slit, is the horizontal angle between the entrance slit and the detection plate, is the electron charge, is the anode voltage of the parallel capacitor.

[0096] It is understandable that by repeating steps S300-500, the energy of the primary ion beam generated in different sampling areas is collected. , based on the energy difference between the primary ion beam and the neutral beam, the plasma potential is obtained The spatial distribution at different radial positions, and according to the formula Calculated radial electric field of plasma .

[0097] Example 2:

[0098] This embodiment provides a diagnostic system for measuring plasma potential and electric field, the system comprising a first obtaining module 701, a first calculating module 702, a second calculating module 703, a third calculating module 704, and a second obtaining module 705, wherein:

[0099] A first obtaining module 701 is configured to select several elements as candidate particle elements based on the acquired operating parameters of the magnetic confinement fusion device, and obtain relevant parameter data, wherein the relevant parameter data includes particle mass data, primary collision ionization cross section data, and secondary collision ionization cross section data, wherein the operating parameters include the background magnetic field of the magnetic confinement fusion device, the electron temperature of the plasma, and the electron density of the plasma;

[0100] The first calculation module 702 is configured to calculate the particle beam trajectory and the effective collision ionization cross section data between the particle and the electron based on the operating parameters and related parameter data, and then calculate the signal-to-noise ratio of the candidate particle element, and select a suitable element as the neutral beam particle element used for the diagnosis according to the signal-to-noise ratio;

[0101] The second calculation module 703 is configured to iteratively calculate, based on the particle mass data of the neutral beam particle element, preset parameters for the particle beam trajectory to pass through the analyzer entrance slit, wherein the preset parameters include incident energy, incident angle, and sampling area;

[0102] The third calculation module 704 is configured to generate ions by heating using a solid-state thermionic source based on a neutral beam particle element, accelerate the ions using a Pierce electrode device to obtain a directed ion beam, and generate a neutral beam with a preset incident energy by exchanging charges between the directed ion beam and a preset neutral gas; and inject the neutral beam into the plasma at a preset incident angle based on preset parameters.

[0103] The second acquisition module 705 is used to analyze and calculate the primary ion beam generated by the collision ionization of the neutral beam in the sampling area using an analyzer to obtain the energy of the primary ion beam; based on the energy difference between the primary ion beam and the neutral beam, the potential of the sampling area is obtained according to the law of conservation of energy, and the above steps are repeated to collect the energy of the primary ion beams generated in different sampling areas, and the spatial distribution of the plasma potential at different radial positions and the radial electric field are obtained, thereby completing the diagnosis.

[0104] Specifically, the first calculation module 702 includes a collision unit 7021:

[0105] Collision Unit 7021: Based on the particle mass data, a neutral beam of a candidate particle element is injected into the plasma at a certain incidence velocity and angle. The neutral beam collides with electrons in the plasma to generate a primary ion beam. The primary ion beam is deflected by the background magnetic field and passes through the plasma. The particle beam trajectory is calculated as follows:

[0106]

[0107] Where, is the beam trajectory, is the differential symbol, for The differential of For time, for The differential of is the incident velocity of the neutral beam, is the particle mass of the candidate particle element, is the charge (neutral beam , primary ion beam , is the electron charge), is the background magnetic field, and the particle's speed along the beam trajectory is Basically unchanged, that is , for other candidate particle elements of the neutral beam, under the same beam trajectory, the incident velocity It can be converted based on the same Larmor radius: ,in is the particle mass of other candidate particle elements.

[0108] Specifically, the first calculation module 702 further includes a third calculation unit 7033, a fourth calculation unit 7034 and a selection unit 7035, wherein:

[0109] The third calculation unit 7033 is used to obtain the effective collision ionization cross section data between the particle and the electron based on the Maxwell rate distribution function, the primary collision ionization cross section data, and the secondary collision ionization cross section data. The calculation formula is as follows:

[0110]

[0111] Where, , is the relative velocity of the particle and the electron, is the particle speed, is the electron speed, is the differential symbol, for The differential of is the Maxwell rate distribution function, is the plasma electron temperature, is the electron mass, is the Boltzmann constant, is the impact ionization cross section, is the effective impact ionization cross section, and the single impact ionization cross section is substituted Get an effective impact ionization cross section , bringing in the secondary impact ionization cross section Secondary effective impact ionization cross section ;

[0112] The fourth calculation unit 7034 is used to calculate the signal-to-noise ratio of the candidate particle element based on the operating parameters, related parameter data, beam trajectory, and effective collision ionization cross-section data. The calculation formula is as follows:

[0113]

[0114] Where, is the plasma electron density, is the entrance slit width, is the differential symbol, for The differential of is the beam trajectory, It is the time for the neutral beam to reach the plasma core and generate a primary ion beam by impact ionization. is the time it takes for the primary ion beam to pass through the plasma, is the signal-to-noise ratio, 、 They are the primary and secondary effective collision ionization cross section data respectively;

[0115] Selection unit 7035: for selecting the candidate particle element with a signal-to-noise ratio greater than The elements are used as the neutral beam particle elements for this diagnosis.

[0116] Specifically, the second calculation module 703 includes a first calculation unit 7031 and a second calculation unit 7032, wherein:

[0117] The first calculation unit 7031 is used to calculate the beam trajectory with different incident speeds, incident angles and sampling areas according to the beam trajectory, wherein the beam trajectory includes the trajectory of the neutral beam reaching the sampling area and the trajectory of the primary ion beam generated after impact ionization;

[0118] The second calculation unit 7032 is used to iteratively calculate the beam trajectory to obtain preset parameter information corresponding to the beam trajectory of the primary ion beam that can pass through the analyzer entrance slit, wherein the preset parameter information includes the neutral beam incident energy, incident angle and sampling area.

[0119] Specifically, the third calculation module 704 includes a selection unit 7041, a focusing unit 7042, and an exchange unit 7043, wherein:

[0120] A selection unit 7041 is used to select a neutral beam particle element based on a signal-to-noise ratio;

[0121] Focusing unit 7042: selects a solid-state thermal ion source corresponding to a neutral beam particle element and heats it, causing overflowing ions to be accelerated using a Pierce electrode device and focused by an electrostatic lens to obtain a directional ion beam;

[0122] Exchange unit 7043: used to introduce the directed ion beam into the neutralization chamber equipment, generate a neutral beam with a preset incident energy by exchanging it with the preset neutral gas charge, and inject the neutral beam into the plasma at a preset incident angle.

[0123] Specifically, the third calculation module 704 further includes a fifth calculation unit 7044, wherein:

[0124] The fifth calculation unit 7044 is used to obtain the potential of the sampling area based on the energy difference between the primary ion beam and the neutral beam. The calculation method is as follows:

[0125]

[0126] in, is the potential of the sampling area, is the primary ion beam energy, is the incident energy of the neutral beam, is the charge of the electron.

[0127] In summary, the present invention is based on a diagnostic system including a neutral beam emitter and an analyzer. The neutral beam emitter is composed of a solid-state thermal ion source, a Pierce electrode, an electrostatic lens, a neutralization chamber and two Faraday cups, and is used to provide a neutral particle beam with a certain energy; the analyzer is composed of an entrance slit, a parallel capacitor and a detection plate, and is used to measure the energy of the primary ion beam generated by the collision ionization of the sampling area. Finally, based on the energy difference between the primary ion beam and the neutral beam, the potential (electric field) and its fluctuations in the sampling area are obtained according to the law of conservation of energy. The characteristics of this scheme are small disturbance and high spatiotemporal resolution. For plasmas with lower temperatures or lower electron densities, a higher signal-to-noise ratio can still be obtained. It is currently the only measurement method that can be used to directly measure the potential and electric field in low-parameter plasmas. It is of great significance to in-depth study of the radial electric field and The physical mechanism by which flow shear suppresses turbulence and improves confinement is of great significance.

[0128] It should be noted that, regarding the system in the above embodiment, the specific manner in which each module performs operations has been described in detail in the embodiment of the method, and will not be elaborated on here. Industrial Applicability

[0129] It can be seen from the embodiments described above that the present application has industrial applicability. Sequence Listing Free Content

[0130] The foregoing description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention are intended to be within the scope of protection of the present invention.

[0131] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any modifications or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be based on the scope of protection of the claims.

Claims

1. A diagnostic method for measuring plasma potential and electric field, characterized in that Including: According to the operating parameters of the magnetic confinement fusion device obtained, several elements are selected as candidate particle elements to obtain relevant parameter data, where the relevant parameter data includes particle mass data, single-collision ionization cross-section data, and double-collision ionization cross-section data, and the operating parameters include the background magnetic field of the magnetic confinement fusion device, the electron temperature of the plasma, and the electron density of the plasma; Based on the operating parameters and the relevant parameter data, the beam trajectory of the particle and the effective collision ionization cross-section data between the particle and the electron are calculated, and then the signal-to-noise ratio of the candidate particle element is calculated. According to the signal-to-noise ratio, a suitable element is selected as the neutral beam particle element used for the diagnosis; Based on the particle mass data of the neutral beam particle element, the preset parameters for the beam trajectory to pass through the analyzer entrance slit are iteratively calculated, where the preset parameters include the incident energy, the incident angle, and the sampling area; Based on the neutral beam particle element, ions are generated by heating with a solid-state thermionic source, and the ions are accelerated by a Pierce electrode device to obtain a directional ion beam, and a neutral beam with a preset incident energy is generated by charge exchange between the directional ion beam and a preset neutral gas charge; Based on the preset parameters, the neutral beam is injected into the plasma at a preset incident angle; The analyzer is used to analyze and calculate the primary ion beam generated by the collision ionization of the neutral beam in the sampling area to obtain the energy of the primary ion beam; based on the energy difference between the primary ion beam and the neutral beam, the potential magnitude of the sampling area is obtained according to the law of conservation of energy, and iterative calculations are repeated to change the preset parameters, and then the energies of the primary ion beams generated in different sampling areas are collected to obtain the spatial distribution of the plasma potential at different radial positions and the radial electric field, and then the diagnosis is completed; The beam trajectory of the particle calculated based on the operating parameters and the relevant parameter data includes: Based on the particle mass data, a neutral beam of a candidate particle element is injected into the plasma at a certain incident velocity and incident angle, and collides with the electrons in the plasma to generate a primary ion beam. The primary ion beam deflects under the action of the background magnetic field and exits the plasma. The calculation formula for the beam trajectory of the particle is as follows: In the formula, is the beam trajectory, is the differential symbol, For Differential of, is time, For Differential of, is the incident velocity of the neutral beam, is the particle mass of the candidate particle element, Charge, neutral beam , a primary ion beam ， is the electronic charge amount, is the background magnetic field. Along the beam trajectory, the moving speed of the particle , for the neutral beams of other candidate particle elements, under the same beam trajectory, the incident velocity It can be obtained by conversion according to the same Larmor radius: , where Is the particle mass of other candidate particle elements; The beam trajectory of the particle and the effective collision ionization cross-section data between the particle and the electron calculated based on the operating parameters and the relevant parameter data, and then the signal-to-noise ratio of the candidate particle element is calculated. According to the signal-to-noise ratio, a suitable element is selected as the neutral beam particle element used for this diagnosis, and it also includes: Based on the Maxwell velocity distribution function, the single-collision ionization cross-section data, and the double-collision ionization cross-section data, the effective collision ionization cross-section data between the particle and the electron is obtained, and its calculation formula is as follows: In the formula, is the relative speed of the particle and the electron, is the particle movement speed, is the electron motion speed, is the differential symbol, For Differential of, is the Maxwell speed distribution function, is the plasma electron temperature, is the electron mass, is the Boltzmann constant, is the impact ionization cross section, is the effective collision ionization cross section, substituting the single collision ionization cross section Obtain the effective ionization cross section for a single collision , and substitute into the secondary impact ionization cross section Obtain the data of the secondary effective collision ionization cross section ； According to the operating parameters, the relevant parameter data, the beam trajectory, and the effective collision ionization cross-section data, the signal-to-noise ratio of the candidate particle element is calculated, and its calculation formula is as follows: Wherein, is the signal-to-noise ratio, is the plasma electron density, is the entrance slit width, is the differential symbol, For Differential of, is the beam trajectory, is the time when the neutral beam reaches the plasma core and collisional ionization occurs to generate a primary ion beam. is the time when the primary ion beam exits the plasma, 、 Are the single and double effective collision ionization cross-section data respectively; According to the signal-to-noise ratio of the candidate particle elements, select those with a signal-to-noise ratio greater than As the neutral beam particle element used for the diagnosis; The analyzer analyzes and calculates the primary ion beam generated by the collision ionization of the neutral beam in the sampling area to obtain the energy of the primary ion beam. Based on the energy difference between the primary ion beam and the neutral beam, the electric potential of the sampling area is obtained according to the law of conservation of energy, including: The analyzer analyzes and calculates the primary ion beam generated by the collision ionization of the neutral beam in the sampling area to obtain the energy of the primary ion beam. Based on the energy difference between the primary ion beam and the neutral beam, the electric potential of the sampling area is obtained according to the law of conservation of energy, and its calculation method is as follows: Among them, is the electric potential of the sampling area, is the primary ion beam energy, is the neutral beam injection energy, is the electron charge.

2. The diagnostic method for measuring plasma potential and electric field according to claim 1, characterized in that, Based on the particle mass data of the neutral beam particle element, the preset parameters for the beam trajectory to pass through the analyzer entrance slit are iteratively calculated, where the preset parameters include the incident energy, incident angle, and sampling area, including: The beam trajectories with different incident velocities, incident angles, and sampling areas are calculated according to the beam trajectory. The beam trajectory includes the trajectory of the neutral beam reaching the sampling area and the trajectory of the primary ion beam generated after collision ionization. The beam trajectory is iteratively calculated to obtain the preset parameter information corresponding to the beam trajectory of the primary ion beam that can pass through the analyzer entrance slit, where the preset parameter information includes the incident energy, incident angle, and sampling area of the neutral beam.

3. The diagnostic method for measuring plasma potential and electric field according to claim 1, characterized in that, Based on the neutral beam particle element, a solid-state thermal ion source is used to heat and generate ions, and a Pierce electrode device is used to accelerate the ions to obtain a directional ion beam. The directional ion beam exchanges charges with a preset neutral gas to generate a neutral beam with a preset incident energy, including: Select the solid-state thermal ion source corresponding to the neutral beam particle element and heat it to overflow ions. The Pierce electrode device is used to accelerate the overflow ions and focus them under the action of an electrostatic lens to obtain a directional ion beam. The directional ion beam is introduced into the neutralization chamber device, and a neutral beam with a preset incident energy is generated by exchanging charges with a preset neutral gas, and the neutral beam is injected into the plasma at a preset incident angle.

4. A diagnostic system for measuring plasma potential and electric field, based on the diagnostic method for measuring plasma potential and electric field according to claim 1, characterized in that, Including: The first acquisition module: used to select several elements as candidate particle elements according to the operating parameters of the obtained magnetic confinement fusion device to obtain relevant parameter data, where the relevant parameter data includes particle mass data, primary collision ionization cross-section data, and secondary collision ionization cross-section data, and the operating parameters include the background magnetic field of the magnetic confinement fusion device, the electron temperature of the plasma, and the electron density of the plasma. The first calculation module: used to calculate the beam trajectory of the particle and the effective collision ionization cross-section data between the particle and the electron based on the operating parameters and the relevant parameter data, and then calculate the signal-to-noise ratio of the candidate particle element, and select a suitable element as the neutral beam particle element used for diagnosis according to the signal-to-noise ratio. The second calculation module: used to iteratively calculate the preset parameters for the beam trajectory of the particle to pass through the analyzer entrance slit based on the particle mass data of the neutral beam particle element, where the preset parameters include the incident energy, incident angle, and sampling area. The third calculation module: used to generate ions by heating with a solid-state thermionic source based on neutral beam particle elements, accelerate the ions using a Pierce electrode device to obtain a directional ion beam, and generate a neutral beam with a preset incident energy through charge exchange between the directional ion beam and a preset neutral gas charge; Based on preset parameters, inject the neutral beam into the plasma at a preset incident angle; The second acquisition module: used to analyze and calculate the primary ion beam generated by the collision ionization of the neutral beam in the sampling area using an analyzer to obtain the energy of the primary ion beam; based on the energy difference between the primary ion beam and the neutral beam, obtain the potential magnitude of the sampling area according to the law of conservation of energy, perform iterative calculations, change the preset parameters, and then collect the energies of the primary ion beams generated in different sampling areas to obtain the spatial distribution of the plasma potential at different radial positions and the radial electric field, and then the diagnosis ends.

5. The diagnostic system for measuring plasma potential and electric field according to claim 4, characterized in that, The first calculation module, which includes: In the formula, is the beam trajectory, is the differential symbol, For Differential of, is time, For Differential of, is the incident velocity of the neutral beam, is the particle mass of the candidate particle element, Charge, neutral beam , a primary ion beam ， is the electronic charge quantity, is the background magnetic field. Along the beam trajectory, the velocity of the particle , for the neutral beams of other candidate particle elements, under the same beam trajectory, the incident velocity It can be obtained by conversion according to the same Larmor radius: , wherein The particle mass of other candidate particle elements.

6. The diagnostic system for measuring plasma potential and electric field according to claim 4, characterized in that, The second calculation module, which includes: The first calculation unit: used to calculate the beam trajectories of different incident velocities, incident angles, and sampling areas according to the beam trajectory, and the beam trajectory includes the trajectory of the neutral beam reaching the sampling area and the trajectory of the primary ion beam generated after collision ionization; The second calculation unit: used to perform iterative calculations on the beam trajectory to obtain the preset parameter information corresponding to the beam trajectory of the primary ion beam that can pass through the analyzer entrance slit, where the preset parameter information includes the incident energy of the neutral beam, the incident angle, and the sampling area.

7. The diagnostic system for measuring plasma potential and electric field according to claim 4, characterized in that, The third calculation module, which includes: The selection unit: used to select neutral beam particle elements based on the signal-to-noise ratio; The focusing unit: used to select the solid-state thermionic source corresponding to the neutral beam particle elements, heat it, overflow ions, accelerate the overflow ions using a Pierce electrode device, and perform focusing under the action of an electrostatic lens to obtain a directional ion beam; The exchange unit: used to introduce the directional ion beam into the neutralization chamber device, generate a neutral beam with a preset incident energy through charge exchange with a preset neutral gas charge, and inject the neutral beam into the plasma at a preset incident angle.

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