A method for actively regulating transport barriers in tokamak plasma

Abstract

This invention belongs to the field of internal transport barrier technology and discloses a method for actively controlling the internal transport barrier of a tokamak plasma. This invention actively controls the pressure and current distribution of the plasma through electron cyclotron waves or other auxiliary heating methods, thereby altering the stability of the neoclassical tearing mode and ultimately achieving a magnetic island-free internal transport barrier operation mode. The control strategy is simplified: it eliminates the need for real-time precise measurement of the radial position and phase of the magnetic island, and also eliminates the need for real-time feedback control of the electron cyclotron wave deposition position and timing; only the injection power of the electron cyclotron wave in the core needs to be adjusted, making the system operation simpler. It also boasts high energy efficiency: depositing electron cyclotron waves in the plasma core, where heating and current-driven absorption efficiency are high, thus requiring relatively low injection power and offering better economic benefits.

Description

Technical Field

[0001] This invention belongs to the field of internal transport barrier technology, and particularly relates to a method for actively controlling the internal transport barrier of a tokamak plasma. Background Technology

[0002] The internal transport barrier is a promising operating mode in future fusion reactors, but its triggering and control remain challenging. Triggering the internal transport barrier using a neoclassical tearing mode magnetic island has proven effective; however, the presence of the island significantly reduces plasma confinement performance and energy storage. Therefore, after successfully triggering the internal transport barrier, it is necessary to develop an efficient and stable control method that can effectively suppress the neoclassical tearing mode while maintaining its existence. Currently, the control of the neoclassical tearing mode mainly relies on electron cyclotron current drive, which is not only difficult to control but also requires high injection power, resulting in poor economic efficiency. Therefore, it is necessary to explore a new strategy that is simpler to operate and more efficient in control.

[0003] Based on the above analysis, the problems and shortcomings of the existing technology are as follows:

[0004] (1) The control process is complex and technically demanding. This is mainly reflected in two aspects: First, it is necessary to use methods such as electron cyclotron radiation diagnosis to accurately measure the radial position and phase information of the magnetic island in real time; second, it is necessary to dynamically modulate the injection angle and timing of the electron cyclotron wave through a real-time feedback system to ensure that the wave energy is accurately deposited inside the magnetic island. Once the beam deviates from the target area, the control efficiency will decrease significantly.

[0005] (2) The control efficiency is low and the economic efficiency is poor. The main reasons include: on the one hand, the electron temperature in the magnetic island region is relatively low, resulting in low absorption efficiency of electron cyclotron waves in this area; on the other hand, even if precise deposition is achieved, tens of megawatts of injection power are still required in future fusion reactors to completely suppress the magnetic island, which will significantly increase operating costs and affect the feasibility of its practical application. Summary of the Invention

[0006] To address the problems existing in the prior art, this invention provides a method for actively controlling the transport barrier inside a tokamak plasma.

[0007] This invention is implemented as follows: A method for actively controlling the transport barrier inside a tokamak plasma includes:

[0008] Step 1: Electron cyclotron waves are deposited in the plasma core, and the plasma pressure and current distribution are actively controlled;

[0009] Step 2: By changing the current distribution, the neoclassical tearing mode magnetic island is caused to move outward and gradually suppressed, thereby improving plasma energy storage while maintaining the internal transport barrier.

[0010] Furthermore, the active control of plasma pressure and current distribution:

[0011] Active control of plasma pressure and current distribution can be achieved by injecting auxiliary heating power into the plasma core region. Specific methods include electron cyclotron wave, ion cyclotron wave, low hybrid wave, or neutral beam injection.

[0012] Furthermore, by altering the current distribution, the neoclassical tearing mode magnetic islands are caused to move outward and are gradually suppressed.

[0013] By changing the current distribution, the rational plane corresponding to the neoclassical tearing mode can be moved outward. During this process, the magnetic island migrates outward with the rational plane, while the position of the internal transport barrier remains stable, thus decoupling the two. As the rational plane moves outward, the magnetic shear near it gradually increases, while the local pressure gradient decreases accordingly. These changes together improve the stability of the neoclassical tearing mode, ultimately causing the magnetic island to disappear. After the magnetic island disappears, the total plasma energy storage will be significantly increased.

[0014] Another object of the present invention is to provide a system for actively controlling the transport barrier inside a tokamak plasma, comprising:

[0015] The deposition module is used to deposit electron cyclotron waves onto the plasma core and actively control the plasma pressure and current distribution.

[0016] The current distribution alteration module is used to change the current distribution, causing the neoclassical tearing mode magnetic island to move outward and be gradually suppressed, thereby increasing plasma energy storage while maintaining the internal transport barrier.

[0017] Another object of the present invention is to provide a computer device including a memory and a processor, the memory storing a computer program that, when executed by the processor, causes the processor to perform the steps of the method for actively controlling the internal transport barrier of a tokamak plasma.

[0018] Another object of the present invention is to provide a computer-readable storage medium storing a computer program that, when executed by a processor, causes the processor to perform the steps of the method for actively controlling the internal transport barrier of a tokamak plasma.

[0019] Another objective of the present invention is to provide an information data processing terminal for implementing the system for actively controlling the transport barrier inside a tokamak plasma.

[0020] Based on the above technical solutions and the technical problems solved, the advantages and positive effects of the technical solution to be protected by this invention are as follows:

[0021] First, this scheme actively modulates the pressure and current distribution of the plasma through electron cyclotron waves or other auxiliary heating methods, thereby altering the stability of the neoclassical tearing mode and ultimately achieving the operation mode of the internal transport barrier in a non-magnetic island. This method has the following main advantages:

[0022] 1. Simplified control strategy: There is no need to measure the radial position and phase of the magnetic island in real time, nor is there a need to perform real-time feedback control on the deposition position and timing of the electron cyclotron wave. Only the injection power of the electron cyclotron wave in the core needs to be adjusted, making the system operation simpler.

[0023] 2. High energy utilization efficiency: Electron cyclotron waves are deposited in the plasma core, where the heating and current-driven absorption efficiency is high, thus requiring relatively low injection power and making it more economical.

[0024] 3. Stable confinement performance: While maintaining the peaked pressure distribution in the core of the internal transport barrier, the total energy storage does not decrease due to the suppression of the magnetic island, and the overall confinement performance is maintained.

[0025] Favorable for long-pulse operation: The small-scale sawtooth collapse of the plasma core helps to prevent impurities from accumulating in the core during long-pulse operation of the fusion reactor in the future and promotes the removal of helium ash, thereby improving the sustainability of operation.

[0026] Secondly, as supplementary evidence of the inventive step of the claims of this invention, it is also reflected in the following important aspects:

[0027] (1) The expected benefits and commercial value of the technical solution of this invention after transformation are as follows:

[0028] Significantly reduced operational complexity and cost: (I) Simplified control, eliminating the need for millisecond-level real-time tracking and precise aiming of the magnetic island position, greatly reducing the engineering difficulty and software development cost of the plasma control system (plasma control and diagnostics); (II) Energy-efficient, concentrating heating power for efficient core deposition, or through multi-method synergistic optimization, can save up to 30%-50% of additional power compared to traditional local current drive. For a fusion reactor requiring tens of megawatts of auxiliary heating, this can save millions to tens of millions of kilowatt-hours of electricity costs annually.

[0029] Performance enhancement: While maintaining high-performance ITB plasma, the NTM magnetic island is eliminated or avoided, increasing plasma energy storage. At the same time, the overall energy gain factor Q is improved due to the reduced demand for auxiliary heating power.

[0030] (2) The technical solution of this invention fills a technical gap in the industry both domestically and internationally:

[0031] The entire process of "first triggering ITB using NTM magnetic islands, and then causing it to move outward and disappear stably through profile control" is clearly proposed and systematized. This fills the operational gap between "using NTM to trigger ITB" and "completely suppressing NTM", forming a closed-loop solution.

[0032] (3) Whether the technical solution of the present invention solves the technical problem that people have long wanted to solve but have never been able to solve successfully:

[0033] To achieve high constraints, an ITB (Inter-Independent Traps) needs to be established, but the strong pressure and gradient of the ITB itself can easily trigger the NTM (Non-Mechanical Traps). Although the NTM magnetic island can be an effective means of triggering the ITB, the existence of the magnetic island will, in turn, reduce the constraint performance.

[0034] This scheme first uses the NTM magnetic island to trigger ITB, and then eliminates the physical conditions for the existence of NTM by changing the global current and pressure distribution, thus realizing "high-confinement ITB plasma without magnetic islands". It has both the extremely high core parameters brought by ITB and avoids the reduction of confinement performance caused by magnetic islands. Attached Figure Description

[0035] Figure 1 This is a flowchart of a method for actively controlling the transport barrier inside a tokamak plasma, provided in an embodiment of the present invention.

[0036] Figure 2 This is a schematic diagram of the system structure for actively regulating internal transport barriers provided in an embodiment of the present invention.

[0037] Figure 3 The graph shows the waveform evolution (left) and electron temperature distribution (right) of key parameters of the J-TEXT#1105725 experimental plasma provided in this embodiment of the invention.

[0038] Figure 4 This is a schematic diagram illustrating the evolution of the positional relationship between the rational surface and the internal transport base points provided in an embodiment of the present invention.

[0039] Figure 5 This is a schematic diagram of the physical principle of actively regulating the internal transport barrier using ECRH, provided in an embodiment of the present invention.

[0040] Figure 6 This is a system structure block diagram of closed-loop active control of the internal transport barrier of a tokamak plasma provided in an embodiment of the present invention. Detailed Implementation

[0041] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0042] like Figure 1 As shown, an embodiment of the present invention provides a method for actively controlling the transport barrier inside a tokamak plasma, comprising the following steps:

[0043] S101 deposits electron cyclotron waves into the plasma core and actively controls the plasma pressure and current distribution.

[0044] S102, by changing the current distribution, causes the neoclassical tearing mode magnetic island to move outward and be gradually suppressed, thereby improving plasma energy storage while maintaining the internal transport barrier.

[0045] like Figure 2 As shown, the system for actively controlling the transport barrier inside a tokamak plasma provided in this embodiment of the invention includes:

[0046] The deposition module is used to deposit electron cyclotron waves onto the plasma core and actively control the plasma pressure and current distribution.

[0047] The current distribution alteration module is used to change the current distribution, causing the neoclassical tearing mode magnetic island to move outward and be gradually suppressed, thereby increasing plasma energy storage while maintaining the internal transport barrier.

[0048] like Figure 3 , Figure 4 The present invention provides an example of achieving an island-free internal transport barrier by actively altering the plasma pressure and current distribution to induce the neoclassical tearing mode magnetic island to move outward and be gradually suppressed:

[0049] By injecting ECRH into the core to change the current distribution, the rational plane corresponding to the neoclassical tearing mode is moved outward. During this process, the magnetic island migrates outward with the rational plane, while the position of the internal transport barrier remains stable, thus decoupling the two. As the rational plane moves outward, the magnetic shear near it gradually increases, while the local pressure gradient decreases accordingly. These changes together improve the stability of the neoclassical tearing mode, ultimately causing the magnetic island to disappear. After the magnetic island disappears, the total plasma energy storage will be significantly increased.

[0050] like Figure 5 The implementation steps and physical principles of actively controlling the internal transport barrier by actively regulating plasma pressure and current distribution provided in this embodiment of the invention are as follows:

[0051] Active control of plasma pressure and current distribution can be achieved by injecting auxiliary heating power into the plasma core region. Specific methods include electron cyclotron wave, ion cyclotron wave, low hybrid wave or neutral beam injection, etc.

[0052] The injection of auxiliary heating power into the core increases the electron temperature in the region, thereby changing the plasma parameters in two ways: firstly, the core resistivity decreases with increasing temperature, and the proportion of ohmic-driven current in the core region increases accordingly; secondly, the pressure profile rises, leading to an increase in the pressure gradient, which in turn increases the proportion of bootstrap current in the internal transport barrier region; these two effects work together to ultimately achieve effective control over the plasma pressure and current distribution.

[0053] This invention does not employ electron cyclotron wave heating or current-driven technology in isolation, nor does it merely passively suppress neoclassical tearing modes. Instead, it constructs an active control method and system with an inherent causal closed loop, focusing on the formation and maintenance mechanism of the transport barrier within tokamak plasma. Its core lies in: actively guiding the evolution path of the magnetic island configuration through the synergistic reconstruction of the pressure and current distribution in the plasma core, transforming the evolution of the neoclassical tearing mode from "transport disruption" to "outward shift and stabilization," thereby achieving stable existence of the internal transport barrier and simultaneous enhancement of plasma energy storage.

[0054] In the specific implementation process, electron cyclotron waves are first precisely deposited into a predetermined radial region of the plasma core using a deposition module. This deposition process does not simply increase the local electron temperature, but rather actively shapes the pressure gradient distribution and local current density distribution within the core through controlled energy and momentum injection. Since the pressure gradient and current profile are key physical quantities determining the magnetic shear structure and a reasonable safety factor distribution, the above-mentioned regulation creates an electromagnetic environment within the plasma that is conducive to maintaining the internal transport barrier.

[0055] Building upon this, the current distribution alteration module does not operate independently. Instead, it relies on the magnetohydrodynamic equilibrium state reconstructed by the aforementioned pressure distribution to further finely adjust the current distribution. Through this adjustment, the magnetic island corresponding to the neoclassical tearing mode is no longer in its original stable or growing condition. Instead, under the combined action of magnetic shear and current gradient, its resonant position undergoes a radial shift. This shift does not expand randomly but is guided to gradually move towards the outer region of the plasma. During this movement, the width of the magnetic island continuously decreases, and its disturbance effect on internal transport diminishes accordingly.

[0056] The above process forms a continuous physical synergistic mechanism: electron cyclotron wave deposition first alters the background distribution of pressure and current; subsequently, the regulated current distribution changes the driving conditions and stability criteria of the neoclassical tearing mode; the magnetic island is actively "pulled" away from the region where the internal transport barrier is located during its evolution and is gradually suppressed; while the internal transport barrier is stably maintained in a lower magnetic disturbance environment, thereby increasing plasma energy storage. This synergistic process is not a linear superposition of individual methods in existing technologies, but rather a holistic regulatory mechanism built around the coupling relationship between the magnetic island, transport barrier, and energy confinement.

[0057] Therefore, this invention achieves controllable guidance of the evolution path of the internal transport barrier by establishing a three-in-one active control closed loop of "pressure distribution - current distribution - magnetic island stability" in the plasma core. Its technical effect depends on the overall mechanism synergy and cannot be obtained by simply combining existing technical means. It has significant creativity and irreplaceability.

[0058] like Figure 3 As shown, in the J-TEXT tokamak device #1105725 discharge, the plasma was in a high safety factor ohmic discharge state before t=0.25 s, with a boundary safety factor q 95 The plasma strength is approximately 5.6, the plasma current is approximately 95 kA, and the average density of the central chord is approximately 1.5 × 10⁻⁶. 19 m -3 . Figure 3 The left side shows the evolution of key plasma parameters over time, while the right side shows the radial distribution of electron temperature at different stages. At t=0.25 s, an off-axis electron cyclotron wave with a power of 300 kW was injected at r / a=0.23, exciting a neoclassical tearing mode magnetic island with m / n=2 / 1 and establishing an L-mode plasma state accompanied by the magnetic island. During this stage, local perturbations in the electron temperature profile near the rational plane were observed, while the overall confinement level remained low, providing initial conditions for subsequent triggering of the internal transport barrier through the magnetic island.

[0059] At t=0.35 s, such as Figure 3 As shown in the ECRH power waveform, depositing another electron cyclotron wave system on the axis with an injected power of approximately 350 kW resulted in a rapid increase in the core electron temperature and the formation of a significant radial strong gradient region, corresponding to the establishment of the internal transport barrier structure. This strong gradient region... Figure 3 The yellow and purple electron temperature profiles on the right are clearly visible. The increase in core electron temperature reduces local resistivity and increases the ohmic current component in the core. On the other hand, it enhances the bootstrap current share by increasing the pressure gradient, thereby causing the evolution of the overall current profile.

[0060] like Figure 4 As shown, the evolution of this current profile causes the position of the 2 / 1 rational plane to gradually shift outward over time, while the position of the internal transport barrier foot (ITB foot) remains relatively stable. As the rational plane shifts outward, its local magnetic shear gradually increases, while the pressure gradient at the corresponding location gradually decreases, thus weakening the driving term of the neoclassical tearing mode and strengthening its stabilizing term. When both reach equilibrium and exceed a critical threshold, the amplitude of the neoclassical tearing mode magnetic island begins to decay and eventually disappears. Figure 3 The third sub-figure on the left also shows that the amplitude of the poloidal magnetic disturbance decreased to the noise level in 0.45 s, which can be considered as the complete disappearance of the magnetic island. Figure 4 After the disappearance of the central magnetic island, a small-scale sawtooth collapse phenomenon occurred in the plasma core. The flip-off radius of the sawtooth collapse is marked with an asterisk. At this time, the plasma still maintained a clear internal transport barrier structure, indicating that the suppression by the magnetic island did not damage the transport barrier performance. Meanwhile, Figure 3 On the electron temperature profile on the right, we can see that the electron temperature profile after the magnetic island is suppressed, corresponding to the purple curve, is different from the electron temperature profile when the magnetic island is present, corresponding to the yellow curve. Not only does it maintain the strong gradient region of the steep internal transport barrier, but the electron temperature in the plasma core is also significantly increased. This indicates that the plasma confinement performance is further improved after the magnetic island is suppressed. Since the average electron density of the central chord does not change significantly, it is believed that the overall energy storage of the plasma is also significantly improved after the magnetic island is suppressed.

[0061] like Figure 5 As shown, the physical mechanism of this process can be summarized as follows: core-assisted heating causes an increase in electron temperature, leading to a decrease in resistivity and an increase in ohmic current. Simultaneously, the increased pressure gradient enhances the bootstrap current. These two effects jointly reshape the current distribution, causing the rational plane to shift and creating magnetic shear and pressure conditions at the rational plane that are more conducive to stabilizing the neoclassical tearing mode, thus achieving the passive suppression and disappearance of the magnetic island. After the magnetic island disappears, the pressure and confinement are further enhanced, and the total plasma energy storage increases significantly.

[0062] like Figure 6 As shown, a closed-loop control process suitable for steady-state operation was constructed based on this physical mechanism. Real-time diagnostics using ECE, Mirnov, and polarization interferometers acquire information on current profiles, rational plane positions, and magnetic island activity. Heating and current drive parameters such as ECRH, ECCD, NBI, and ICRH are dynamically adjusted based on feedback, enabling the system to achieve a closed-loop balance between "suppressing magnetic islands—maintaining internal transport barriers—eliminating impurities—stabilizing constraints." Once the magnetic island is completely suppressed, the system enters a steady-state maintenance mode, and small-amplitude sawtooth oscillations can be triggered as needed to expel impurities and helium ash, thus achieving a unified system of high constraint, no magnetic islands, and long-pulse operation.

[0063] Therefore, combining Figures 1 to 6 It can be seen that the present invention achieves stable suppression of the neoclassical tearing mode magnetic island and long-term maintenance of the internal transport barrier by inducing the self-organized evolution of global pressure and current through core auxiliary heating, thus avoiding the complexity of precise alignment control of the traditional magnetic island. It has significant technical advantages in improving confinement performance, enhancing operational stability and achieving steady-state high-performance plasma operation.

[0064] The technical effects achieved by the present invention are mainly reflected in two aspects: First, it achieves complete suppression of the neoclassical tearing mode magnetic island. Figure 3The experimental results of the discharge of #1105725 on the J-TEXT tokamak device are presented. Figure 3 The poloidal magnetic perturbation amplitude in the third row from the left reflects the width of the magnetic island. Its saturation amplitude reaches approximately 2 Gs. Through active control via ECRH injection in the core, the magnetic island amplitude begins to decrease after approximately 0.42 s, reaching a near-zero signal-to-noise level after approximately 0.45 s, indicating complete suppression of the magnetic island. Secondly, it improves plasma confinement performance after magnetic island suppression, i.e., increases energy storage. This is manifested in… Figure 3 On the right side, the electron temperature distribution shows that the electron temperature profile after the disappearance of the magnetic island (represented by the purple curve) is significantly higher in the plasma core region (around R=1.05 m) than the electron temperature profile with the presence of the magnetic island (represented by the yellow curve), indicating an improvement in plasma confinement performance.

[0065] Example 1: Basic Implementation Method of Core-Specific Electron Cyclotron Deposition

[0066] During the operation of the tokamak device, electron cyclotron waves are directionally deposited in the core region with a plasma normalized radius of approximately 0.3 using an adjustable mirror system. Under the influence of the electron cyclotron waves, the core electron temperature increases significantly, leading to a decrease in local resistivity and an increase in the ohmic current component. Simultaneously, the pressure gradient in the core is redistributed. Against this backdrop, the neoclassical tearing mode rational plane, originally located near the internal transport barrier, gradually moves radially outward. As the rational plane moves outward, the magnetic shear at its location increases, while the local pressure gradient decreases, disrupting the conditions for magnetic island growth. The width of the magnetic island gradually shrinks and is eventually suppressed. Throughout this process, the internal transport barrier structure remains intact, and the plasma energy storage is enhanced.

[0067] Example 2: Implementation of Cooperative Reconfiguration of Ohmic Current and Bootstrap Current

[0068] While maintaining the electron cyclotron wave deposition position, the core electron temperature variation was kept within a controllable range by finely adjusting the deposition power. After the core resistivity decreased, not only did the ohmic current component increase, but the pressure gradient adjustment also triggered a redistribution of the bootstrap current. These two types of currents formed a synergistic reconstruction effect in the radial direction, causing the safety factor profile to shift outwards as a whole. This outward shift is not a simple translation, but rather accompanied by the reshaping of the magnetic shear structure, thereby enhancing the stability of the neoclassical tearing mode during the rational plane outward shift and preventing magnetic islands from intruding into the internal transport barrier region.

[0069] Example 3: Dynamic Regulation Implementation Method of Closed-Loop Feedback Control

[0070] A plasma diagnostic system is introduced into the device to acquire real-time signals of current distribution, rational plane position, and magnetic island activity. When the growth of the neoclassical tearing mode magnetic island is detected, the control system automatically increases the electron cyclotron deposition power, enhances core heating and resistivity control, and causes the rational plane to move outward rapidly. When the magnetic island activity is detected to be suppressed, the system reduces or stabilizes the deposition power, keeping the core electron temperature within a preset range, thereby maintaining the stability of the internal transport barrier structure and achieving a stable energy storage level over a long period.

[0071] Example 4: Implementation of Sawtooth Oscillation Limitation Control

[0072] Building upon the aforementioned closed-loop control, a sawtooth oscillation with limited amplitude is further permitted within the core. By precisely controlling the electron cyclotron deposition power and timing, the sawtooth oscillation serves only to remove high-Z impurities from the core without triggering large magnetic disturbances. This implementation effectively improves core purity and enhances the long-term sustainability of the internal transport barrier while suppressing neoclassical tearing mode magnetic islands.

[0073] Example 5: Implementation of Multi-Wave Coordinated Regulation

[0074] Based on electron cyclotron waves, ion cyclotron waves or low-hybrid waves are introduced as auxiliary control methods. Electron cyclotron waves are mainly used for core electron temperature and resistivity regulation, while ion cyclotron waves or low-hybrid waves are used for compensatory control of pressure and current distribution over a wider radial region. Under the synergistic effect of multiple waves, the current distribution reconstruction is smoother, the rational plane outward shift process is more stable, the magnetic island suppression effect is enhanced, and the maintenance time of the internal transport barrier is significantly prolonged.

[0075] Example 6: Implementation under high-power long-pulse operation conditions

[0076] Under high-power, long-pulse discharge conditions, electron cyclotron waves are continuously deposited into the core, and the deposition power is adjusted in real-time to maintain the core's electron temperature, resistivity, and pressure gradient within a dynamic equilibrium range. Even if a neoclassical tearing mode triggering trend emerges during long-term operation, it can be preemptively shifted outward and suppressed by controlling the rational surface position, thereby preventing transport barrier collapse. This implementation verifies the engineering applicability of this technical solution in future steady-state fusion operation scenarios.

[0077] As can be seen from the above six embodiments, the present invention achieves active and stable maintenance of the internal transport barrier by comprehensively and synergistically controlling the pressure distribution, resistivity distribution, current distribution and magnetic island evolution path. Its technical effect depends on a complete mechanism chain and has significant creativity and full feasibility.

[0078] It should be noted that embodiments of the present invention can be implemented in hardware, software, or a combination of both. The hardware portion can be implemented using dedicated logic; the software portion can be stored in memory and executed by a suitable instruction execution system, such as a microprocessor or dedicated-design hardware. Those skilled in the art will understand that the above-described devices and methods can be implemented using computer-executable instructions and / or included in processor control code, for example, such code provided on a carrier medium such as a disk, CD, or DVD-ROM, a programmable memory such as read-only memory (firmware), or a data carrier such as an optical or electronic signal carrier. The devices and modules of the present invention can be implemented by hardware circuitry such as very large-scale integrated circuits or gate arrays, semiconductors such as logic chips, transistors, or programmable hardware devices such as field-programmable gate arrays, programmable logic devices, etc., or by software executed by various types of processors, or by a combination of the above-described hardware circuitry and software, such as firmware.

[0079] 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, equivalent substitutions, and improvements made by those skilled in the art within the scope of the technology disclosed in the present invention, and within the spirit and principles of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A method for actively controlling the transport barrier inside a tokamak plasma, characterized in that, Includes the following steps: Electron cyclotron waves are deposited in the plasma core to increase the core electron temperature and change the pressure and resistivity distribution. The changes in pressure and resistivity distribution cause the plasma current distribution to be reconstructed, thereby causing the rational plane corresponding to the neoclassical tearing mode to move outward. During the outward movement of the rational plane, the magnetic shear at the rational plane is enhanced and the pressure gradient is reduced, so as to improve the stability of the neoclassical tearing mode and suppress the neoclassical tearing mode magnetic island. While suppressing the magnetic island in the neoclassical tearing mode, the internal transport barrier structure is maintained, thereby increasing the total plasma energy storage.

2. The method as described in claim 1, characterized in that, The electron cyclotron wave is deposited in the core region with a plasma normalized radius of less than 0.

4.

3. The method as described in claim 1, characterized in that, By increasing the core electron temperature, the local resistivity of the plasma is reduced, thereby increasing the ohmic current component and reconstructing the current distribution together with the bootstrap current.

4. A system for actively controlling the transport barrier inside a tokamak plasma to implement the method according to any one of claims 1 to 3, characterized in that, include: A deposition module is used to deposit electron cyclotron waves onto the plasma core to alter the pressure and resistivity distribution. The current distribution control module is used to reconstruct the plasma current distribution based on changes in pressure distribution and resistivity distribution and to cause the rational surface to move outward. The magnetic island stabilization module is used to enhance magnetic shear and reduce pressure gradient at the rational surface during the outward movement of the rational surface, so as to suppress the neoclassical tearing mode magnetic island. The transport barrier maintenance module is used to maintain the internal transport barrier structure and enhance plasma energy storage after the magnetic island is suppressed.

5. The system as described in claim 4, characterized in that, The deposition module is configured to deposit electron cyclotron waves in a region with a plasma normalized radius of less than 0.

4.

6. The system as described in claim 4, characterized in that, The current distribution control module determines the current reconstruction direction based on the changes in pressure gradient and resistivity.

7. A closed-loop control method for actively regulating the transport barrier inside a tokamak plasma, characterized in that, include: Acquire plasma current distribution, rational surface location, and neoclassical tearing mode magnetic island activity state; When the presence of a neoclassical tearing mode magnetic island is detected, the electron cyclotron wave deposition power is adjusted to change the pressure distribution and resistivity distribution and drive the rational surface to move outward. When the suppression of the neoclassical tearing mode magnetic island is detected, the electron cyclotron wave deposition power is adjusted to maintain the stability of the internal transport barrier structure and plasma energy storage.

8. The method as described in claim 7, characterized in that, The electron temperature in the plasma core is maintained within a preset range by adjusting the electron cyclotron deposition power.

9. The method as described in claim 7, characterized in that, While maintaining the internal transport barrier structure, the amplitude of sawtooth oscillations is controlled to remove core impurities.

10. The method as described in claim 1, characterized in that, In addition to electron cyclotron waves, pressure and current distributions are also synergistically controlled through ion cyclotron waves, low hybrid waves, or neutral beam injection.

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