Adjusting system and method for realizing steady-state billion-degree ion temperature

Abstract

The invention discloses an adjusting system and method for realizing steady-state billion-degree ion temperature, and relates to the technical field of magnetic confinement nuclear fusion, and the system comprises a central control unit, and a neutral beam injection unit, a central spiral pipe and an air supply unit of which the output ends are connected with plasma in a vacuum chamber. The neutral beam injection unit is used for heating high-energy neutral atoms emitted by the plasma; the central spiral tube is used for generating and controlling plasma current; the gas supply unit is used for conveying working gas into the vacuum chamber; and the central control unit can respectively adjust the neutral beam injection unit, the central spiral pipe and the air supply unit so as to obtain the required steady-state ion temperature. By adjusting the beam energy and power of the neutral beam injection unit, the plasma electron density and the current climbing rate, the plasma has very high heating power density, ion energy transportation is reduced, heating efficiency is improved, and therefore the steady-state ion temperature of hundred million degrees is obtained.

Description

Technical Field

[0001] This invention relates to the field of magnetic confinement nuclear fusion technology, specifically to a system and method for regulating the steady-state temperature of ions at hundreds of millions of degrees. Background Technology

[0002] Nuclear fusion energy possesses the advantages of being clean, safe, and renewable, and may be one of the most important ways to ultimately solve humanity's energy problems. Therefore, the development of nuclear fusion energy has received high attention both domestically and internationally. The ignition of fusion and the realization of fusion energy require a plasma ion temperature (…). ), electron density ( ) and energy-constrained time ( The triple product satisfies the well-known Lawson criterion. In tokamak devices, electron density is typically limited by the Greenwald density limit (nGW = Ip / πa², where Ip is the plasma current and a is the plasma minima): when the experimental electron density exceeds the Greenwald limit, the plasma undergoes a large burst. This characteristic makes it difficult for magnetic confinement fusion devices to operate normally at very high electron densities. The energy confinement time depends on the ratio of plasma energy storage to total heating power; this parameter is influenced by a combination of factors, including plasma current, magnetic field, and electron density, and is difficult to significantly increase.

[0003] Therefore, achieving an ion temperature of hundreds of millions of degrees is a crucial step and primary breakthrough for realizing fusion ignition and obtaining fusion energy. my country's currently operational HL-3 and EAST devices have achieved transient ion temperatures exceeding hundreds of millions of degrees, but they are far from meeting the steady-state ion temperature requirement for nuclear fusion. How to stably achieve and maintain an ion temperature of hundreds of millions of degrees has become a key entry point and important research topic for improving the core parameters of China's fusion project. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention aims to provide a system and method for achieving a steady-state ion temperature of hundreds of millions of degrees Celsius. This system can adjust the energy and power of the neutral beam injection unit, the plasma electron density, and the current ramp-up rate to enable the plasma to have a very high heating power density, while reducing ion energy transport and improving heating efficiency, thereby achieving a steady-state ion temperature of hundreds of millions of degrees Celsius.

[0005] This invention is achieved through the following technical solution: A regulation system for achieving a steady-state ion temperature of 100 million degrees Celsius includes: The central control unit, as well as the neutral beam injection unit, central helical tube, and gas delivery unit, whose output ends are all connected to the plasma in the vacuum chamber; The neutral beam injection unit is used to heat the plasma by emitting high-energy neutral atoms. The central helical tube is used to generate and control plasma current; The gas feeding unit is used for feeding working gas into the vacuum chamber. The central control unit can respectively adjust the neutral beam injection unit to achieve optimal beam energy, adjust the central spiral tube to achieve optimal current ramping rate, and adjust the gas feeding unit to achieve optimal electron density, so as to obtain the required steady-state ion temperature.

[0006] Further optimization also includes a laser interferometer for measuring the average electron density of the plasma; the output end of the laser interferometer is connected with the central control unit.

[0007] Further optimization also includes a charge exchange spectrometer for measuring the ion temperature of the plasma; the output end of the charge exchange spectrometer is connected with the central control unit.

[0008] Further optimization also includes a Thomson scattering device for measuring the electron temperature of the plasma; the output end of the Thomson scattering device is connected with the central control unit.

[0009] Further optimization also includes a display for displaying the fundamental waveforms of the output power of the neutral beam injection unit, the plasma current, the electron density, the electron temperature and the ion temperature.

[0010] Further solutions: The application also provides an adjusting method of the adjusting system for achieving steady-state gigaelectronvolt ion temperature, including the following steps: S1: making the neutral beam injection unit mainly heat ions, and determining the optimal beam energy of the neutral beam injection unit; S2: keeping the beam energy and injection power of the neutral beam injection unit and the plasma current unchanged, scanning the electron density to make the electron density increase, and monitoring the electron density and the ion temperature in real time; S3: comparing the ion temperature information under different electron densities, finding the maximum ion temperature, and recording the corresponding electron density at this time, that is, the optimal electron density; S4: keeping the beam energy and injection power of the neutral beam injection unit and the electron density unchanged, scanning the plasma current ramping rate, and measuring the ion temperature in real time; S5: comparing the ion temperature information under different current ramping rates, finding the maximum ion temperature, and recording the corresponding current ramping rate at this time, that is, the optimal current ramping rate; S6: finally, controlling the neutral beam injection unit to work in the optimal beam energy state, controlling the central spiral tube to achieve the optimal current ramping rate, and controlling the gas feeding unit to control the gas feeding amount so that the plasma has the optimal electron density, so as to obtain the gigaelectronvolt ion temperature.

[0011] Further optimization, the step S1 further comprises the following specific steps: S11: fixing the neutral beam injection unit beam energy and injection power and keeping the electron density and plasma current unchanged, and measuring the electron temperature in real time; S12: comparing the size of the neutral beam energy with the energy threshold value, and scanning the neutral beam injection unit according to the comparison result to ensure that the neutral beam injection unit is mainly heated by ions, and then determining the optimal beam energy of the neutral beam injection unit.

[0012] Further optimization, the formula of the energy threshold value is: ; Wherein The mass of ions and electrons is m, The mass of beam particles is m, and Te is the electron temperature.

[0013] Further optimization, when the neutral beam energy is greater than the energy threshold value, the neutral beam injection unit is mainly heated by electrons; when the neutral beam energy is equal to or less than the energy threshold value, the neutral beam injection unit is mainly heated by ions.

[0014] Further optimization, the steps S1-S3 and steps S4-S5 all need to carry out several times of plasma physics experiments respectively.

[0015] Compared with the prior art, the present application has the following advantages and beneficial effects: 1. The adjustment system and method for realizing steady-state billion-degree ion temperature provided by the present application can ensure that the neutral beam injection unit is mainly heated by ions and that the plasma has very high heating power density by adjusting the neutral beam injection unit beam energy and power and the plasma electron density, and using laser interferometer and Thomson scattering diagnosis for real-time feedback.

[0016] 2. The adjustment system and method for realizing steady-state billion-degree ion temperature provided by the present application can realize the magnetic configuration that is beneficial to suppressing microturbulence by adjusting the plasma current climbing rate, so as to reduce ion energy transport and improve heating efficiency. BRIEF DESCRIPTION OF DRAWINGS

[0017] In order to more clearly illustrate the technical scheme of the exemplary embodiments of the present application, the following will briefly introduce the drawings needed to be used in the embodiments. It should be understood that the following drawings only show some embodiments of the present application, and therefore should not be regarded as a limitation on the scope, and for those skilled in the art, other related drawings can also be obtained without creative labor. In the drawings: Figure 1The present invention provides a flowchart of a system for regulating a steady-state ion temperature of 100 million degrees Celsius.

[0018] The attached diagram shows the markings and corresponding component names: 1-Central control unit, 2-Neutral beam injection unit, 3-Central helical tube, 4-Gas delivery equipment, 5-Plasma, 6-Laser interferometer, 7-Charge exchange spectrometer, 8-Thomson scattering device, 9-Display. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the embodiments and accompanying drawings. The illustrative embodiments and descriptions of the present invention are only used to explain the present invention and are not intended to limit the present invention.

[0020] Example 1: This embodiment 1 provides a system for regulating the steady-state ion temperature, such as... Figure 1 As shown. The specific technical solution is as follows: A regulating system for achieving a steady-state ion temperature of 100 million degrees Celsius mainly consists of a central control unit 1, a neutral beam injection unit 2, a central solenoid 3, a gas delivery unit 4, a plasma 5, a laser interferometer 6, a charge exchange spectrometer 7, a Thomson scattering device 8, and a display 9.

[0021] The connection method is as follows: the output end of the central control unit 1 is connected to the input ends of the neutral beam injection unit 2, the central solenoid 3 and the gas supply unit 4. The output ends of the neutral beam injection unit 2, the central solenoid 3 and the gas supply unit 4 are all connected to the plasma 5. The plasma 5 is connected to the input ends of the laser interferometer 6, the charge exchange spectrometer 7 and the Thomson scattering device 8. The output ends of the laser interferometer 6, the charge exchange spectrometer 7 and the Thomson scattering device 8 are all connected to the display 9. The output ends of the laser interferometer 6 and the Thomson scattering device 8 are also connected to the central control unit 1.

[0022] By adopting the above scheme, the beam energy and power of the neutral beam injection unit 2 and the electron density of the plasma 4 can be adjusted, and real-time feedback can be provided using the laser interferometer 6 and Thomson scattering diagnostics to ensure that the neutral beam injection unit 2 mainly heats ions and that the plasma 5 has a very high heating power density. Secondly, by adjusting the current ramp rate of the plasma 5, a magnetic configuration that is conducive to suppressing micro-turbulence can be achieved, thereby reducing ion energy transport and improving heating efficiency.

[0023] In the above structure, the central control unit 1 is the core part for implementing high ion temperature experiments. It is mainly used to control the neutral beam injection unit 2, the central solenoid 3 and the gas supply unit 4, thereby controlling the output power, plasma current and electron density output waveform of the neutral beam injection unit 2.

[0024] The neutral beam injection unit 2 is a device that heats the plasma 5 by emitting high-energy neutral atoms, which can heat both electrons and ions, depending on the size relationship between the neutral beam energy and the energy threshold (E , wherein is the mass of ions and electrons, is the mass of beam particles, and Te is the electron temperature), the heating efficiency can be optimized by adjusting the beam energy and power of the neutral beam injection unit 2.

[0025] The central solenoid 3 is the main device for generating and controlling the plasma current, and the toroidal current is generated by the change of the current in the primary coil. The output of different toroidal currents can be achieved by controlling the change of the current in the primary coil. The gas feeding unit 4 is a key system for the formation of the plasma 5 and an important means for controlling the electron density. The working gas injected into the vacuum chamber is electrically charged in the high-voltage environment to form the plasma. The electron density of the plasma can be controlled by controlling the gas injection amount of the gas feeding unit 4.

[0026] The plasma 5 is a highly ionized quasi-neutral gas, which is the carrier for achieving high ion temperature in the present application. The basic characteristics of the plasma 5 can be described by parameters such as electron density, electron temperature and ion temperature.

[0027] The laser interferometer 6 is a laser diagnostic for measuring the average electron density of the plasma string. The electron density signal is obtained by comparing the phase difference between the signals of the two light paths that pass through and do not pass through the plasma 5. It is very sensitive to the density perturbation caused by the instability of the plasma 5. In the present application, it is mainly used for real-time measurement of the average electron density of the electron line and feedback of the related information to the central control unit. It is also used for monitoring the excited magnetohydrodynamic instability in the plasma 5.

[0028] The charge exchange spectrometer 7 is a diagnostic tool for measuring the ion temperature of the plasma 5, and is also the core measurement and diagnosis of the present application. It analyzes the energy distribution of neutral particles generated by the charge exchange between high-energy ions and neutral particles to infer ion temperature information. In the present application, it is mainly used for monitoring the time evolution of ion temperature.

[0029] The Thomson scattering device 8 is one of the most accurate diagnostic systems for measuring electron temperature. It measures the Doppler frequency shift of the scattered wavelength caused by the thermal motion of electrons to obtain electron temperature information. In the present application, it is mainly used for monitoring the time evolution of electron temperature to determine whether the neutral beam injection unit heats ions or electrons.

[0030] The display 9 is used to show the basic waveforms of the output power, plasma current, electron density, electron temperature and ion temperature of the neutral beam injection unit.

[0031] Embodiment 2: This embodiment 2 is further optimized on the basis of embodiment 1, and provides a regulating method for realizing steady-state gigawatt ion temperature, comprising the following specific steps: First step, fixing the beam energy and injection power of the neutral beam injection unit 2 and keeping the electron density and plasma current unchanged, measuring the electron temperature by using the Thomson scattering device 8, showing the electron temperature information on the display 9 and feeding back to the central control unit 1.

[0032] Second step, according to the measured electron temperature, comparing the size of the neutral beam energy and the energy threshold value (E ), when the neutral beam energy is greater than E , the neutral beam injection unit is mainly heating electrons, and when the neutral beam energy is equal to or less than E , the neutral beam injection unit is mainly heating ions; Therefore, the neutral beam injection unit 2 needs to be adjusted at this time, and the neutral beam injection unit 2 is scanned to ensure that the neutral beam injection unit 2 is mainly heating ions, and then the best beam energy of the neutral beam injection unit 2 is determined.

[0033] Third step, keeping the beam energy and injection power of the neutral beam injection unit 2 and the plasma current unchanged, scanning the electron density to make the electron density increase, monitoring the electron density information by using the laser interferometer 6 and measuring the ion temperature by using the charge exchange spectrometer 7, showing the electron density and ion temperature information on the display 9 and feeding back the electron density information to the central control unit 1.

[0034] Fourth step, comparing the ion temperature information under different electron densities, finding the maximum value of the ion temperature and recording the corresponding electron density at this time, which is the best electron density.

[0035] Fifth step, keeping the beam energy and injection power of the neutral beam injection unit 2 and the electron density unchanged, scanning the plasma current ramp rate (such as 500kA / s, 1000kA / s, 1500kA / s), measuring the ion temperature by using the charge exchange spectrometer 7 and showing the ion temperature information on the display 9.

[0036] Sixth step, comparing the ion temperature information under different current ramp rates, finding the maximum value of the ion temperature and recording the corresponding current ramp rate at this time, which is the best current ramp rate.

[0037] Step 7, through the central control unit 1 control neutral beam injection unit 2, central solenoid 3 and gas supply unit 4, so that the neutral beam injection unit 2 works in the best beam energy state, through the control of the central solenoid 3 to achieve the best current ramp rate, through the gas supply unit 4 control gas supply amount so that the plasma has the best electron density, under the experimental conditions, the plasma 5 can obtain very high ion temperature; The first step to the fourth step needs to carry out multiple plasma physics experiments, the goal is to ensure that the neutral beam injection unit is mainly heated by ions and the plasma has very high heating power density, so as to ensure the heating source term.

[0038] The fifth step to the sixth step needs to carry out multiple plasma physics experiments, the goal is to adjust the plasma current ramp rate to achieve a magnetic configuration that is conducive to suppressing microturbulence, thereby reducing ion heat transport leakage term and improving heating efficiency.

[0039] The seventh step needs to repeat multiple times to carry out physical experiments to verify the feasibility and stability of a system and method for achieving high ion temperature.

[0040] Through the above scheme, the neutral beam injection unit beam energy and power, plasma electron density and current ramp rate can be adjusted to make the plasma have very high heating power density, reduce ion energy transport and improve heating efficiency, so as to obtain stable billion-degree ion temperature.

[0041] The above specific embodiments further illustrate the purpose, technical solutions and beneficial effects of the present application. It should be understood that the above description is only a specific embodiment of the present application and is not used to limit the protection scope of the present application. Any modification, equivalent replacement, improvement, etc. within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A system for regulating a steady-state ion temperature of 100 million degrees Celsius, characterized in that, include: The central control unit (1), and the neutral beam injection unit (2), central helical tube (3) and gas delivery unit (4) whose output ends are all connected to the plasma (5) in the vacuum chamber. The neutral beam injection unit (2) is used to heat the plasma (5) by emitting high-energy neutral atoms; The central helical tube (3) is used to generate and control the plasma (5) current; The gas delivery unit (4) is used to deliver working gas into the vacuum chamber; The central control unit (1) can adjust the neutral beam injection unit (2) to achieve the optimal beam energy, adjust the central helical tube (3) to achieve the optimal current ramp-up rate, and adjust the gas delivery unit (4) to achieve the optimal electron density, so as to obtain the required steady-state ion temperature.

2. The system for regulating a steady-state ion temperature of 100 million degrees Celsius according to claim 1, characterized in that, It also includes a laser interferometer (6) for measuring the average electron density of the plasma (5); the output of the laser interferometer (6) is connected to the central control unit (1).

3. The system for regulating a steady-state ion temperature of 100 million degrees Celsius according to claim 1, characterized in that, It also includes a charge exchange spectrometer (7), which is used to measure the ion temperature of the plasma (5); the output of the charge exchange spectrometer (7) is connected to the central control unit (1).

4. The system for regulating a steady-state ion temperature of 100 million degrees Celsius according to claim 1, characterized in that, It also includes a Thomson scattering device (8) for measuring the electron temperature of the plasma (5); the output of the Thomson scattering device (8) is connected to the central control unit (1).

5. A system for regulating a steady-state ion temperature of 100 million degrees Celsius according to claim 1, characterized in that, It also includes a display (9) for displaying basic waveforms of the output power, plasma current, electron density, electron temperature and ion temperature of the neutral beam injection unit (2).

6. A method for regulating a system for achieving a steady-state ion temperature of 100 million degrees Celsius according to any one of claims 1 to 5, characterized in that, Includes the following steps: S1: Make the neutral beam injection unit (2) mainly heated ions and determine the optimal beam energy of the neutral beam injection unit (2); S2: Keep the beam energy and injection power and plasma current of the neutral beam injection unit (2) constant, scan the electron density to make the electrons continuously increase, and monitor the electron density and ion temperature in real time; S3: Compare the ion temperature information under different electron densities, find the maximum ion temperature and record the corresponding electron density, which is the optimal electron density; S4: Keep the beam energy, injection power and electron density of the neutral beam injection unit (2) constant, scan the plasma current ramp rate and measure the ion temperature in real time; S5: Compare the ion temperature information under different current ramp-up rates, find the maximum ion temperature and record the corresponding current ramp-up rate, which is the optimal current ramp-up rate. S6: Finally, control the neutral beam injection unit (2) to work in the optimal beam energy state, control the central helical tube (3) to achieve the optimal current ramp-up rate, and control the gas delivery unit (4) to control the gas delivery volume so that the plasma has the optimal electron density, thereby obtaining the required steady-state ion temperature.

7. The adjustment method for an adjustment system for achieving a steady-state ion temperature of billions of degrees Celsius according to claim 6, characterized in that, Step S1 further includes the following specific steps: S11: Fix the beam energy and injection power of the neutral beam injection unit (2) and keep the electron density and plasma current constant, and measure the electron temperature in real time; S12: Compare the neutral beam energy with the energy threshold, and scan the neutral beam injection unit (2) according to the comparison results to ensure that the neutral beam injection unit is mainly heated ions, and then determine the optimal beam energy of the neutral beam injection unit.

8. The adjustment method for an adjustment system for achieving a steady-state ion temperature of billions of degrees Celsius according to claim 7, characterized in that, The formula for the energy threshold is: ； in For the mass of ions and electrons, Let Te be the mass of the beam particles, and Te be the electron temperature.

9. The adjustment method for an adjustment system for achieving a steady-state ion temperature of billions of degrees Celsius according to claim 7, characterized in that, When the neutral beam energy is greater than the energy threshold, the neutral beam injection unit mainly heats electrons; when the neutral beam energy is equal to or less than the energy threshold, the neutral beam injection unit mainly heats ions.

10. The adjustment method for an adjustment system for achieving a steady-state ion temperature of 100 million degrees Celsius according to claim 6, characterized in that, Each of the steps S1-S3 and S4-S5 requires conducting several plasma physics experiments.

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