A method and system for controlling plasma rotation

Abstract

The application relates to the technical field of plasma digital control, and provides a method and system for controlling plasma rotation, which comprises the following steps: moving an electrode head to a preset magnetic surface according to target window positioning data, applying a deflection bias after satisfying a vacuum condition, making two magnetic surfaces form a radial potential difference, inducing a radial electric field and generating a radial current; combining magnetic field data to determine a Lorentz force distribution, generating a moment and constructing a momentum source area to drive plasma rotation; and combining density parameters to generate an adjustment instruction to optimize the rotation state. The method can control plasma rotation and a boundary electric field under the premise of a complex three-dimensional magnetic field configuration without increasing impurity sources, and realizes boundary transport inhibition and constraint performance improvement.

Description

Technical Field

[0001] This invention relates to the field of plasma digital control technology, and more specifically, to a method and system for controlling plasma rotation. Background Technology

[0002] The content in this section only provides background information related to this invention and may not constitute prior art.

[0003] Plasma rotation plays a crucial physical role in magnetically confined plasma (MCP) devices, controlling transport, suppressing turbulence, and stabilizing magnetohydrodynamic instabilities. In conventional MCP devices, plasma rotation is primarily driven by momentum input generated by neutral beam injection, and can also be spontaneously generated through mechanisms such as non-axisymmetric magnetic field structures or turbulent Reynolds stress. However, for MCP devices operating under circumferential current, the lack of significant plasma current drive results in a much lower level of spontaneous plasma rotation compared to conventional devices, making it difficult to meet the requirements for improved plasma confinement, instability suppression, and high-performance operation modes. While some MCP devices employing complex three-dimensional magnetic field configurations have improved plasma equilibrium, orbital confinement, and transport characteristics through magnetic field configuration optimization, active actuation and digital control methods for plasma rotation remain scarce. Therefore, there is an urgent need to develop digital control technologies for plasma rotation that offer controllability, localization, and real-time response capabilities.

[0004] Electrode biasing (EB), as a technique for actively controlling plasma rotation, induces a localized radial electric field in the plasma by applying a voltage at specific magnetic surface locations at the plasma edge or core. This, in turn, drives the plasma to rotate in the poloidal or circumferential direction via E×B drift. This technique has been experimentally verified in various conventional magnetically confined plasma devices and simple magnetic mirror devices, demonstrating significant advantages in controlling boundary local modes, suppressing plasma turbulence, triggering transport barriers, and improving energy confinement. However, in magnetically confined plasma devices with complex three-dimensional magnetic field configurations, developing a digital control system for plasma rotation based on bias electrodes requires overcoming a series of technical challenges. A mature technical solution for achieving active, controllable, and steady-state control of plasma rotation in such devices has not yet been developed.

[0005] The core shortcomings of existing technologies are as follows: First, magnetically confined plasma devices with complex three-dimensional magnetic field configurations generally lack active driving and digital control methods for plasma rotation with controllability, localization, and real-time response capabilities. Their spontaneous rotation level cannot meet the needs of improving confinement, suppressing instability, and achieving high-performance operation. Second, although bias electrode technology has been successfully applied in conventional magnetically confined plasma devices and simple magnetic mirror devices, existing technical solutions cannot adapt to complex three-dimensional magnetic field configurations. At the same time, they also face unresolved technical challenges such as the asymmetry of plasma rotation space, the easy introduction of additional impurity sources, and the extremely high electrode thermal load under long-pulse operation. There is currently no digital control system for bias electrodes suitable for devices with complex three-dimensional magnetic field configurations, and it is impossible to achieve active, controllable, and steady-state digital regulation of plasma rotation in such devices. Summary of the Invention

[0006] The purpose of this invention is to provide a method and system for controlling plasma rotation to improve the aforementioned problems. To achieve this purpose, the technical solution adopted by this invention is as follows:

[0007] In a first aspect, this application provides a method for controlling plasma rotation, comprising:

[0008] Spatial positioning data of the target window of the target device is obtained by electrical digital sampling, and radial displacement control command is generated based on the spatial positioning data; according to the radial displacement control command, the electrode head is moved radially to the preset magnetic surface position of the plasma inside the target device.

[0009] Gas pressure data of the area where the electrode head is located is obtained by electronic digital sampling, and a judgment is made by digital threshold comparison. When the gas pressure data meets the preset vacuum conditions, a bias application command is generated.

[0010] According to the bias application command, a deflection bias is applied to the electrode head located at the preset magnetic surface position through the transmission line to change the plasma potential of the magnetic surface where the electrode head is located, so that the outermost closed magnetic surface remains at ground potential due to contact with the limiter on the target device, and a radial potential difference is formed between the magnetic surface where the electrode head is located and the outermost closed magnetic surface.

[0011] Based on the radial potential difference, a radial electric field is induced in the plasma region between the magnetic surface where the electrode head is located and the outermost closed magnetic surface. A radial current is generated in the plasma between the magnetic surface where the electrode head is located and the outermost closed magnetic surface through the closed conductive loop formed by the electrode head, plasma, limiter and bias circuit.

[0012] The magnetic field data inside the target device is obtained by electrical digital sampling. The Lorentz force distribution is determined based on the radial current and magnetic field data. The circumferential torque and the poloidal torque are generated based on the Lorentz force distribution. A momentum source region is constructed in the plasma region between the magnetic surface where the electrode head is located and the outermost closed magnetic surface to drive the plasma to generate circumferential rotation and poloidal rotation.

[0013] The density parameters of the plasma are obtained, and an adjustment command is generated based on the polarity of the deflection bias voltage, the structural dimensions of the electrode head, the amplitude of the deflection bias voltage, the radial position of the electrode head, and the density parameters. The adjustment command is used to control the conduction direction and intensity of the radial current, and adjust the operating state and flow shear characteristics of the plasma circumferential rotation and polar rotation to the target requirements.

[0014] Further, the electrode head is moved radially to a predetermined magnetic surface position of the plasma inside the target device, specifically including:

[0015] The system acquires three-dimensional magnetic field configuration data of the target device, extracts the radial coordinate values ​​corresponding to the preset magnetic surface position, and converts the radial coordinate values ​​into a rotation step control quantity for the drive motor. Based on the rotation step control quantity, a pulse drive signal is generated, which drives the push rod through the servo motor to move the electrode head radially. At the same time, the actual radial displacement of the electrode head is collected in real time through a grating displacement sensor. The actual radial displacement is compared with the radial coordinate values. When the comparison result meets the preset position deviation threshold, a position locking signal is generated to stop the drive of the servo motor.

[0016] Furthermore, the step of generating a bias application command when the gas pressure data meets the preset vacuum conditions specifically includes:

[0017] Gas pressure data after vacuum connection is collected using resistance gauges and ionization gauges; the gas pressure data is compared with the pressure standard corresponding to the preset vacuum conditions; when the gas pressure data meets the preset pressure standard, it is determined that the vacuum conditions are met, and a bias pressure application command is generated.

[0018] Furthermore, a radial current is generated in the plasma between the magnetic surface where the electrode head is located and the outermost closed magnetic surface through the closed conductive loop formed by the electrode head, plasma, limiter, and bias circuit. Specifically, this includes:

[0019] According to the bias application command, the power module applies a bias voltage to the electrode head through the transmission line, forming a bias current in the closed conductive loop formed by the electrode head, plasma, limiter and bias circuit.

[0020] Obtain the magnetic surface area of ​​the magnetic surface where the electrode head is located, the large radius of the magnetic surface where the electrode head is located, and the small radius of the magnetic surface where the electrode head is located;

[0021] The radial current density is determined based on the bias current, magnetic surface area, large radius, and small radius; based on the current density, a radial current is formed in the plasma region between the magnetic surface where the electrode head is located and the outermost closed magnetic surface.

[0022] Furthermore, the bias current is obtained using the following formula:

[0023]

[0024] In the formula, This is the bias current; The magnetic surface area of ​​the magnetic surface where the electrode head is located; The current density is the radial current. The large radius at the magnetic surface where the electrode head is located; It is the small radius at the magnetic surface where the electrode head is located.

[0025] Furthermore, the operating states and flow shear characteristics of the plasma circumferential and polar rotations are adjusted to meet the target requirements, specifically including:

[0026] By adjusting the gradient distribution of the radial potential difference, the intensity and spatial distribution of the radial electric field, and the plasma circumferential rotation velocity and shear rate determined by the radial electric field and the poloidal magnetic field, the flow shear characteristics can meet the target requirements for suppressing plasma turbulence.

[0027] Furthermore, after adjusting the operating states and flow shear characteristics of the plasma circumferential and polar rotation to the target requirements, the following steps are also included:

[0028] The radial displacement signal of the electrode head is acquired in real time by a grating displacement sensor. After the radial displacement signal is converted into an electrical pulse signal, it is processed to obtain the actual radial position information of the electrode head. At the same time, the actual bias voltage signal and actual current signal of the electrode head are acquired in real time by the power supply module. The actual radial position information, actual bias voltage signal, and actual current signal are compared with the preset parameters of the adjustment command. Based on the comparison results, the output parameters of the deflection bias voltage and the radial position of the electrode head are dynamically adjusted to maintain the rotation state and flow shear characteristics of the plasma at the target requirements, thereby realizing closed-loop control of the plasma rotation state.

[0029] Secondly, this application also provides a system for controlling plasma rotation, comprising:

[0030] The drive module includes a drive motor and an electrode head connected to the drive motor. The drive motor is fixed to the target window and is used to acquire the spatial positioning data of the target window (device window flange) and generate radial displacement control commands. In response to the radial displacement control commands, the drive motor drives the push rod to move the electrode head radially to the preset magnetic surface position of the plasma inside the target device.

[0031] The vacuum measurement module collects gas pressure data of the area where the electrode head is located through resistance gauge and ionization gauge, and generates a bias application command when the gas pressure data meets the preset vacuum conditions.

[0032] The power supply module includes a bias circuit. The power supply module is electrically connected to the electrode head via a transmission line. In response to a bias application command, the power supply module applies a deflection bias voltage to the electrode head located at a preset magnetic surface position via the transmission line to change the plasma potential of the magnetic surface where the electrode head is located. The outermost closed magnetic surface is kept at ground potential due to contact with a limiter. The limiter is installed in the vacuum chamber of the target device and grounded, forming a radial potential difference between the magnetic surface where the electrode head is located and the outermost closed magnetic surface.

[0033] The electrode head contacts the plasma and is electrically connected to the bias circuit of the power module via a transmission line. The limiter and the bias circuit form a conductive path through the plasma, making the electrode head, plasma, limiter, and bias circuit a closed conductive loop. The closed conductive loop is used to generate a radial current in the plasma between the magnetic surface where the electrode head is located and the outermost closed magnetic surface. Based on the radial current and the magnetic field data obtained from the target device, a Lorentz force distribution is generated. The Lorentz force distribution is used to construct a momentum source region in the plasma region between the magnetic surface where the electrode head is located and the outermost closed magnetic surface to drive the plasma to generate circumferential and poloidal rotation.

[0034] The adjustment module includes a grating displacement sensor connected to a drive motor for real-time acquisition of the radial displacement signal of the electrode head. The module also acquires plasma density parameters and obtains the polarity and amplitude of the deflection bias voltage from the power supply module. Based on the polarity of the deflection bias voltage, the structural dimensions of the electrode head, the amplitude of the deflection bias voltage, the radial position of the electrode head, and the density parameters, adjustment commands are generated. These commands control the conduction direction and intensity of the radial current, adjusting the plasma's circumferential and polar rotation operating states and flow shear characteristics to the target requirements.

[0035] Furthermore, the electrode head is integrally formed from the head and the rod. The head has a disc-shaped structure, and the rod has a cylindrical structure. The diameter of the head is larger than the diameter of the rod, and the end face of the head is flat and perpendicular to the axis of the rod, so as to increase the effective contact area between the electrode head and the plasma.

[0036] Furthermore, the electrode head is made of graphite.

[0037] The beneficial effects of this invention are as follows:

[0038] This invention utilizes precise electrode control and the synergy of electro-magnetic effects. First, it acquires the spatial positioning data of the stellarator device's window flange, generating a radial displacement control command to move the electrode head radially to a preset magnetic surface position in the plasma. Then, it acquires the gas pressure data of the region where the electrode head is located. When a preset vacuum condition is met, a deflection bias is applied, changing the plasma potential of the magnetic surface where the electrode head is located. This ensures that the outermost closed magnetic surface remains grounded due to contact with the stellarator limiter, thereby creating a radial potential difference between the two magnetic surfaces. Based on this potential difference, a radial electric field is induced, simultaneously through the electrode head, etc. A closed conductive loop consisting of plasma, limiters, and bias circuits generates radial current. Subsequently, magnetic field data within the stellarator is acquired, and the Lorentz force distribution is determined based on the radial current. This generates circumferential and poloidal moments and constructs a momentum source region, driving the plasma to rotate circumferentially and poloidally. Finally, by acquiring plasma density parameters and combining them with the polarity of the deflection bias, electrode head structure dimensions, bias amplitude, electrode head radial position, and density parameters, adjustment commands are generated to control the conduction direction and intensity of the radial current, adjusting the plasma rotation and flow shear characteristics to the target requirements. This satisfies the requirement of controlling plasma rotation and boundary electric field under complex three-dimensional magnetic field configurations without adding impurity sources; thus improving the suppression and confinement performance of plasma boundary transport in a quasi-toroidal stellarator. Attached Figure Description

[0039] Figure 1 A flowchart of a method and system for controlling plasma rotation provided by the present invention;

[0040] Figure 2 This is a schematic diagram of the bias electrode system in this invention;

[0041] Figure 3 This is a schematic diagram of the electrode head structure in this invention;

[0042] Figure 4 This is a schematic diagram of the current and voltage output range of the power module in this invention;

[0043] Figure 5 This is a schematic diagram of the current and voltage output waveforms of the power module in this invention.

[0044] In the diagram: 1. Outermost closed magnetic surface; 2. Magnetic surface where the electrode is located; 3. Limiter; 4. Radial current; 5. Rod; 6. Head. Detailed Implementation

[0045] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0046] Example 1

[0047] like Figure 1 As shown in the embodiment of the present invention, a method for controlling plasma rotation includes:

[0048] S101: Spatial positioning data of the target window of the target device is obtained through electrical digital sampling, and radial displacement control command is generated based on the spatial positioning data; according to the radial displacement control command, the electrode head is moved radially to the preset magnetic surface position of the plasma inside the target device.

[0049] Specifically, this step aims to provide a precise basis for the spatial position of the electrode for subsequent radial electric field induction and plasma rotation drive. Its principle revolves around "spatial reference establishment - digital motion conversion - closed-loop position feedback" to achieve precise radial positioning of the electrode head, which can effectively solve the technical problem of electrode and magnetic surface adaptation under three-dimensional magnetic field configuration.

[0050] First, spatial positioning data of the target window (i.e., the window flange) of the target device (e.g., the quasi-toroidal symmetric stellarator CFQS) is acquired. Radial displacement control commands are generated based on the spatial positioning data. The device window flange is a fixed reference for the support frame in the external support of the mechanical module. Its spatial positioning data is the core basis for constructing the reference coordinate system for the radial movement of the electrode head. The principle is to establish the motion reference of the electrode head by using the fixed spatial position of the flange. This can avoid the electrode head moving direction deviating from the radial direction of the magnetic surface due to reference deviation. It adapts to the spatial asymmetry of the three-dimensional magnetic field configuration of CFQS and ensures that the moving direction of the electrode head is consistent with the radial direction of the target magnetic surface. For example, using the spatial coordinates of the CFQS window flange No. 46 as the reference, the generated radial displacement control command can accurately point to the plasma edge magnetic surface region corresponding to the window.

[0051] Then, according to the radial displacement control command, the electrode head is moved radially to the preset magnetic surface position of the plasma inside the quasi-toroidal stellarator. As the core component of the electrode module, the precise alignment of the electrode head with the preset magnetic surface is a prerequisite for subsequent application of bias voltage and induction of the radial electric field. The principle is to convert the electrical signal control command into mechanical linear motion, realizing the spatial position control of the electrode head towards the target magnetic surface. The beneficial effect is to ensure the locality of the bias voltage effect, meet the CFQS's requirement for localized control of plasma rotation, and adapt to the edge plasma control requirements under low-parameter (central magnetic field 0.1T) operating conditions. The specific implementation method is as follows:

[0052] Firstly, the three-dimensional magnetic field configuration data of the stellarator is acquired, and the radial coordinate values ​​corresponding to the preset magnetic surface positions are extracted. These radial coordinate values ​​are then converted into rotation step control quantities for the drive motor. For example, based on the three-dimensional quasi-toroidal symmetrical magnetic field configuration data of CFQS, the radial coordinate values ​​of the preset edge magnetic surface at a specific distance from the outermost closed magnetic surface are extracted. These radial coordinate values ​​are then converted into rotation step control quantities for the servo motor through kinematic transformation. The principle is to convert spatial coordinate parameters into digital mechanical motion parameters that the motor can recognize, thereby achieving precise digital control of positioning, improving the accuracy of electrode head positioning, and breaking through the technical bottleneck of three-dimensional magnetic field configuration and electrode adaptation.

[0053] Secondly, a pulse drive signal is generated based on the rotation step control quantity, which drives the push rod via a servo motor to move the electrode head radially. The servo motor is the core of the mechanical module, possessing high positioning accuracy, a wide speed range, and rapid dynamic response. The push rod, as the force transmission component, connects the servo motor and the electrode head. Taking edge magnetic surface positioning under the CFQS center magnetic field condition of 0.1T as an example, after receiving the pulse drive signal, the servo motor drives the push rod radially and smoothly through mechanical transmission, thereby moving the electrode head towards the preset magnetic surface. The principle is to achieve precise transmission of electrical energy to mechanical linear motion through electromechanical conversion, ensuring the smoothness of the electrode head movement and the dynamic response speed, meeting the technical requirements of real-time control of plasma rotation. Simultaneously, a grating displacement sensor collects the actual radial displacement of the electrode head in real time, comparing the actual radial displacement with the radial coordinate value. Among them, the grating displacement sensor is the position detection component of the data acquisition module. It is rigidly connected to the external drive mechanism and can convert the radial displacement of the electrode head into an electrical pulse signal and acquire it in real time. The principle is to build a closed-loop position feedback system to realize real-time position monitoring during the movement of the electrode head. The beneficial effect is to capture the position deviation in the positioning process in a timely manner and avoid the problem of magnetic surface deviation caused by excessive advancement or failure of the electrode head to reach the correct position.

[0054] Third, when the comparison result meets the preset position deviation threshold, a position locking signal is generated, and the servo motor drive is stopped. The preset position deviation threshold is set to the micrometer level according to the experimental requirements of CFQS low-parameter operation. When the deviation between the actual radial displacement and the preset radial coordinate value falls within this threshold range, the system generates a position locking signal and cuts off the servo motor drive power. The principle is to achieve precise termination of electrode head positioning through threshold determination. The beneficial effect is to ensure that the electrode head is stably fixed at the preset magnetic surface position, avoiding the impact of positional fluctuations on the stable formation of the subsequent radial electric field, and providing a stable spatial position basis for the induction of radial current 4.

[0055] S102 acquires gas pressure data of the area where the electrode head is located through digital sampling, and makes a judgment by comparing digital thresholds. When the gas pressure data meets the preset vacuum conditions, a bias application command is generated.

[0056] Specifically, the gas pressure data in the area where the electrode head is located relies on the gas pressure data obtained after vacuum connection between the CF35 resistance gauge and the CF35 ionization gauge configured in the external support of the mechanical module. The principle is to utilize the precise detection characteristics of the resistance gauge and the ionization gauge for different vacuum ranges to achieve real-time acquisition of the full range of gas pressure in the plasma region at the edge of the stellarator where the electrode head is located. Here, "vacuum connection" specifically refers to the vacuum connection state formed between the area where the electrode head is located and the main vacuum chamber of the stellarator after the gate valve between the stellarator bias electrode system and the main vacuum chamber is opened. Combined with the experimental scenario of the CFQS quasi-toroidal symmetrical stellarator, that is, after the gate valve is opened, the CF35 resistance gauge is used to detect the pressure data in the low vacuum range, and the CF35 ionization gauge is used to detect the pressure data in the high vacuum range. The two work together to complete the gas pressure acquisition in the edge magnetic surface region corresponding to window 46 where the electrode head is located. The principle of this implementation method is that the dual-gauge collaborative detection achieves full coverage of the vacuum range, thereby improving the accuracy and comprehensiveness of pressure data acquisition and meeting the leakage rate requirements of the stellarator's ultra-high vacuum system. The gas pressure data is compared with the pressure standard corresponding to the preset vacuum conditions. Real-time collected pressure data is numerically compared with the preset ultra-high vacuum pressure standard for plasma experiments under CFQS low-parameter operating conditions. This objective numerical comparison enables accurate determination of whether the vacuum environment complies with standards, avoiding subjective errors from manual judgment and ensuring the accuracy and consistency of vacuum environment determination, thus meeting the standardized requirements of the experiment. When the gas pressure data meets the preset pressure standard, the vacuum condition is deemed met, and a bias application command is generated. The command generation logic is triggered by the numerical comparison result. Compliant pressure data directly triggers the bias application command and transmits it to the power module, providing a start signal for the subsequent application of deflection bias voltage to the electrode head by the high-power DC eddy power supply. In the CFQS experimental scenario, when the collected pressure data meets the background vacuum requirements of the CFQS quasi-toroidal stellarator, the system immediately generates a bias application command.

[0057] S103, according to the bias application command, a deflection bias is applied to the electrode head located at the preset magnetic surface position through the transmission line to change the plasma potential of the magnetic surface where the electrode head is located, so that the outermost closed magnetic surface 1 maintains the ground potential due to contact with the limiter 3 on the target device, and a radial potential difference is formed between the magnetic surface where the electrode head is located and the outermost closed magnetic surface 1.

[0058] Specifically, the bias application command is the core signal that triggers the power supply module to operate. It can directly activate the power supply module to output a deflection bias voltage to the electrode head. The power supply module provides external voltage to the electrodes. In this invention, a high-power DC vortex power supply is selected. The vortex function enables a wider range of voltage and current output compared to existing DC power supplies, and it has current and voltage stepped waveform programming functions as well as overvoltage and overcurrent protection functions. See the diagram for the current and voltage output range and waveform. Figure 4 and Figure 5 Furthermore, this power supply also features real-time monitoring and acquisition of voltage and current, enabling data acquisition. The transmission line, serving as the connection between the vacuum chamber and the internal electrode head of the stellarator, ensures stable physical transmission of bias voltage from the power module to the electrode head. Its principle relies on the structural characteristics of the transmission line to achieve directional transmission of bias energy, avoiding losses or interference from the complex electromagnetic field inside the stellarator during transmission, ensuring the accuracy and timeliness of bias voltage application, and meeting the stellarator's technical requirements for real-time control of plasma rotation. For example, at the preset magnetic surface position on the plasma edge corresponding to CFQS46 window, after receiving the bias voltage application command, the power module immediately applies a bias voltage, adapted to the low-parameter operating conditions of the device, to the electrode head positioned on that magnetic surface via the transmission line, completing the directional application of the bias voltage. The core function of applying deflection bias to the electrode head is to change the plasma potential of the magnetic surface where the electrode head is located. The principle is that the intervention of the external deflection bias breaks the original potential equilibrium state of the plasma in that magnetic surface region, achieving localized active modulation of the plasma potential. This is not a naturally formed potential state. The beneficial effect is that it allows the magnetic surface where the electrode head is located to form an artificially controllable potential state, providing a controllable potential basis for the formation of subsequent potential differences. This meets the CFQS's requirement for localized control of plasma rotation and is suitable for plasma control scenarios under three-dimensional magnetic field configurations. The outermost closed magnetic surface 1 maintains a ground potential due to contact with the limiter 3 on the stellarator. The principle is that the limiter 3, as a fixed ground reference component of the stellarator, forms an equipotential structure after direct contact with the outermost closed magnetic surface 1, ensuring that the outermost closed magnetic surface 1 is always in a stable zero-potential state, without fluctuations with the plasma environment. This establishes a fixed and stable potential reference for plasma potential control, eliminating the random fluctuation problem of plasma potential at the stellarator boundary; ensuring the stability and controllability of the subsequently formed potential difference, meeting the CFQS's requirement for a stable plasma environment under low-parameter operation with a central magnetic field of 0.1T.

[0059] Based on the potential state of the magnetic surface where the electrode head is located after being regulated, and the stable ground potential of the outermost closed magnetic surface 1, a radial potential difference is naturally formed between the two. The value is obtained by subtracting the sheath potential drop at the electrode surface from the externally applied deflection bias voltage. The potential drop generated by the sheath layer formed at the interface between the electrode and the plasma is a key physical quantity affecting the radial potential difference, and its relevant calculation formula is as follows:

[0060] (1)

[0061] In the formula, For deflection bias; This represents the sheath potential drop on the electrode surface;

[0062] The physical law that the electric field is the negative spatial gradient of potential, combined with the potential of the outermost closed magnetic surface 1, allows us to understand the relationship between the electric field and the potential of the outermost closed magnetic surface. The characteristic of ≈0 allows us to obtain the radial electric field. The calculation formula is as follows:

[0063] (2)

[0064] In the formula, The potential of magnetic surface 2 where the electrode is located; The small radius of the electrode position; Let be the small radius of the outermost closed magnetic surface 1.

[0065] The principle is that the potential difference between different magnetic surfaces is the core physical prerequisite for the formation of an electric field in plasma. By actively adjusting the potential of the magnetic surface where the electrode head is located, the magnitude of the potential difference between the two can be directly changed, achieving flexible control of the radial potential difference. This forms an adjustable radial potential difference, which becomes the key physical basis for inducing a radial electric field in plasma and driving plasma rotation. It effectively solves the technical problem of the lack of active control methods for plasma rotation in quasi-toroidal stellarators, and adapts to the core requirement of CFQS to achieve controllable and steady-state control of plasma rotation.

[0066] S104, based on the radial potential difference, induces a radial electric field in the plasma region between the magnetic surface where the electrode head is located and the outermost closed magnetic surface 1, and generates a radial current 4 in the plasma between the magnetic surface where the electrode head is located and the outermost closed magnetic surface 1 through the closed conductive loop formed by the electrode head, plasma, limiter 3 and bias circuit.

[0067] Specifically, based on the formation of a radial potential difference, a radial electric field is induced in the plasma region between the magnetic surface where the electrode head is located and the outermost closed magnetic surface 1, relying on this potential difference. Simultaneously, the electrode head, plasma, limiter 3, and bias circuit together form a closed conductive loop, thereby generating a radial current 4 in the plasma between the two magnetic surfaces. This step is the core physical process of converting the electrical control signal into plasma force, laying a crucial foundation for subsequent torque generation and plasma rotation drive. The induction of the radial electric field relies on the radial potential difference as its core physical premise. The controllable potential gradient between different magnetic surfaces directly induces a stable electric field distributed radially in the plasma conductive medium. The direction and spatial distribution of this electric field perfectly match the three-dimensional magnetic surface structure of the quasi-toroidal stellarator. This principle ensures that the radial electric field acts only on the target plasma control region, preventing the electric field from diffusing into non-target regions, effectively improving the electric field utilization efficiency, and adapting to the spatially asymmetric magnetic field configuration characteristics of the quasi-toroidal stellarator. The closed conductive loop is constructed with the electrode head as the bias potential input terminal and the limiter 3 as the ground potential reference terminal. The plasma serves as the intermediate conductive medium connecting the two poles, and together with the external bias circuit, a complete current conduction path is formed. This loop structure relies on the stable grounding characteristics of the limiter 3 and the precise positioning characteristics of the electrode head to ensure that the current conduction path is fixed and without additional loss, avoiding current interruption caused by loop breakage or poor contact, and providing a reliable path guarantee for the stable generation of radial current 4.

[0068] From the infinitesimal form of Ohm's law, the radial current density is... The formula relating to the radial electric field is as follows:

[0069] (3)

[0070] In the formula, Plasma conductivity reflects the ability of plasma to conduct radial current 4, and its value is determined by background parameters such as plasma density and temperature.

[0071] In the specific generation process of radial current 4, firstly, according to the bias application command, the power module applies a deflection bias voltage to the electrode head at the preset magnetic surface position through the transmission line. This forms a bias current in the closed conductive loop composed of the electrode head, plasma, limiter 3, and bias circuit. The principle is that the bias application command can precisely activate the electrical signal output logic of the power module, and the transmission line can transmit the deflection bias voltage to the electrode head without loss or interference, making the electrode head a directional potential node in the loop. This drives the charge to move radially in a directional manner within the closed loop, forming a bias current. This method can... To achieve instantaneous triggering and stable output of bias current, the dynamic response requirements of real-time plasma control of stellarator are met, avoiding the impact of bias current start-up delay or amplitude fluctuation on subsequent control effects. Taking the edge plasma magnetic surface region corresponding to window 46 of the CFQS quasi-ring symmetrical stellarator as an example, after the electrode head is accurately positioned on the preset magnetic surface of this region and the vacuum environment meets the requirements, the bias application command can directly trigger the power supply module to work, forming a bias current in the closed loop that is adapted to the low-parameter operating conditions of the central magnetic field of 0.1T, providing the basic current value for the quantitative generation of radial current 4.

[0072] Subsequently, the magnetic surface area, major radius, and minor radius parameters of the magnetic surface where the electrode head is located are obtained. These parameters are core indicators characterizing the spatial geometry of the plasma magnetic surface of a quasi-toroidal stellarator, accurately reflecting the spatial scale and structural characteristics of the radial current conduction region. Acquiring these parameters avoids current distribution judgment errors caused by missing magnetic surface geometric information, adapts to the asymmetric geometric characteristics of the CFQS three-dimensional quasi-toroidal symmetric magnetic surface, and ensures the objectivity and accuracy of subsequent current parameter calculations.

[0073] Finally, the current density of radial current 4 is determined by combining the bias current value, magnetic surface area, and large and small radius parameters. Based on this current density, a stable radial current 4 is formed in the plasma region between the magnetic surface where the electrode head is located and the outermost closed magnetic surface 1. The principle is that by matching the total bias current with the geometric parameters of the magnetic surface, the current conduction intensity per unit space in the plasma region can be quantified, thereby precisely controlling the distribution and conduction intensity of radial current 4. This control method can realize the quantitative and controllable generation of radial current 4, so that the amplitude and distribution of radial current 4 completely match the edge plasma control requirements under the low parameter operation of CFQS. This avoids plasma disturbance caused by excessive current intensity and prevents plasma motion from being unable to be effectively driven by excessively low current intensity. At the same time, it ensures that radial current 4 is uniformly conducted radially along the magnetic surface, providing a stable current basis for the uniform distribution of Lorentz force in the future.

[0074] The magnitude of the bias current is the absolute value of the product of the radial current density and the magnetic surface area at the electrode, and the magnetic surface area can be obtained from the large and small radii of the magnetic surface.

[0075] (4)

[0076] The formula is derived from formula (4):

[0077] (5)

[0078] In the formula, This is the bias current; The magnetic surface area of ​​the magnetic surface where the electrode head is located; The current density of radial current 4; The large radius at the magnetic surface where the electrode head is located; It is the small radius at the magnetic surface where the electrode head is located.

[0079] In bias electrode experiments, such as Figure 2 As shown, the bias current in the circuit is not unlimitedly adjustable, but is limited by the ion saturation current. That is, the maximum value of the bias current is equal to the ion saturation current. This is the core physical constraint of current generation in the bias electrode system, and also an important benchmark for subsequent quantitative control of the radial current. The ion saturation current is derived from the physical definition of plasma ion saturation current, and the formula is derived by combining plasma background parameters such as charge number and electron density with the effective contact area of ​​the electrode.

[0080] (6)

[0081] In the formula, Indicates the number of charges; Indicates electron density; Indicates the effective area of ​​the electrode; Represents the Boltzmann constant; Indicates the plasma mass number; Indicates electron temperature; Indicates ion temperature; Indicates the mass of the ion.

[0082] Substituting the typical parameters of hydrogen plasma under low-parameter operating conditions of CFQS into formula (6), the correlation between ion saturation flow and effective electrode contact area under these operating conditions can be simplified and derived:

[0083] (7)

[0084] S105 acquires magnetic field data within the target device (i.e., the stellarator) through electrical digital sampling. Based on the radial current 4 and the magnetic field data, the Lorentz force distribution is determined. Circumferential and poloidal moments are generated based on the Lorentz force distribution. A momentum source region is constructed within the plasma region between the magnetic surface of the electrode head and the outermost closed magnetic surface 1 to drive the plasma to generate circumferential and poloidal rotations.

[0085] Specifically, magnetic field data is the core physical basis for the electromagnetic interaction between radial current 4 and magnetic field. The three-dimensional quasi-toroidal symmetric magnetic field configuration of the quasi-toroidal stellarator determines the spatial distribution characteristics of the magnetic field. For example, in the edge plasma control region corresponding to window CFQS46, collecting spatial distribution data of the poloidal and circumferential magnetic fields in this region can provide a magnetic field basis that fits the actual device for the subsequent analysis and determination of the Lorentz force.

[0086] The Lorentz force distribution is determined based on radial current 4 and magnetic field data. The principle is that the radial current 4 interacts electromagnetically with the magnetic field within the stellarator to generate a Lorentz force. The spatial distribution of this force is determined by the conduction strength and direction of the radial current 4, as well as the spatial distribution characteristics of the magnetic field. By combining the spatial characteristics of the two with the three-dimensional magnetic surface structure of the quasi-toroidal stellarator, the actual distribution of the Lorentz force can be accurately determined. This achieves precise quantification of the Lorentz force distribution, ensuring a high degree of fit between the Lorentz force distribution and the target plasma control region, avoiding unnecessary plasma disturbances caused by additional Lorentz forces in non-target regions. In CFQS, based on the radial current 4 and three-dimensional magnetic field data of its edge plasma region, the Lorentz force can be precisely determined to be distributed only in the preset plasma control region between the magnetic surface where the electrode head is located and the outermost closed magnetic surface 1.

[0087] The plasma circumferential flow velocity can be derived from the E×B drift principle. The calculation formula is as follows:

[0088] (8)

[0089] In the formula, This is the polar magnetic field inside the stellarator.

[0090] This formula is the core basis for calculating the circumferential rotational velocity of plasma under this mechanism; by taking the radial partial derivative of the circumferential velocity formula and combining it with the physical definition of flow shear as the radial gradient of the circumferential velocity, the flow shear formula can be derived:

[0091] (9)

[0092] Since the radial variation of the poloidal magnetic field is negligible, the flow shear is approximately positively correlated with the radial gradient of the radial electric field. Flow shear is a key physical quantity for suppressing plasma turbulence and improving the plasma confinement performance of magnetically confined nuclear fusion devices. Simultaneously, based on the momentum change relationship of the Lorentz force, the formula for the time-varying rate of the circumferential flow velocity can be derived.

[0093] (10)

[0094] In the formula, The plasma mass density reflects the direct effect of the radial current 4 on the plasma rotation acceleration.

[0095] Based on the Lorentz force distribution, circumferential and poloidal torques are generated respectively. The principle is that the Lorentz force serves as the power source for the plasma region, and its components in different directions will respectively form torques that drive the plasma to move in the circumferential and poloidal directions. The magnitude and direction of the torques are directly determined by the actual distribution characteristics of the Lorentz force. The output characteristics of the two types of torques can be precisely controlled by the spatial distribution of the Lorentz force, so as to achieve the controllable generation of circumferential and poloidal torques and meet the experimental requirements of CFQS for multi-directional rotation control of plasma. For example, when the CFQS operates at a low parameter of 0.1T at the center magnetic field, based on the Lorentz force distribution in its edge control region, circumferential and poloidal torques adapted to the plasma characteristics of the region can be generated to provide directional power for the rotation of the plasma.

[0096] A momentum source region is constructed in the plasma region between the magnetic surface where the electrode head is located and the outermost closed magnetic surface 1 to drive the plasma to generate circumferential and polar rotation. The principle is that the circumferential torque and the polar torque will form a continuous momentum input in the plasma region, thereby constructing a stable momentum source region. This region can provide a continuous and controllable power basis for plasma rotation, so that the plasma can generate directional circumferential and polar rotation under the joint drive of the two types of torques. This solves the technical problems of low spontaneous rotation level and lack of active driving means in quasi-toroidal stellarators, and realizes the active driving of plasma rotation.

[0097] The formula for calculating bias power can be derived from Joule's law:

[0098] (11)

[0099] In the formula, The sheath resistance formed by the sheath layer on the electrode surface belongs to plasma resistance;

[0100] The Ampere force on the electrode can be derived from Ampere's law. The calculation formula is as follows:

[0101] (12)

[0102] In the formula, The magnetic field strength inside the stellarator; This is the bias current; It is the effective length of the current along the direction of the magnetic field lines.

[0103] Calculations show that the bias power obtained from formula (11) is much smaller than the plasma heating power of 10kW under low-parameter operation conditions of CFQS. That is, the contribution of the bias-injected energy to the total plasma heating is negligible, and it will not produce additional heating effects or change the temperature distribution of electrons / ions. Therefore, the bias electrode is used in this invention as a technical means to actively control the boundary electric field and plasma rotation, which meets the design requirements.

[0104] S106: Obtain the density parameters of the plasma. Based on the polarity of the deflection bias voltage, the structural dimensions of the electrode head, the amplitude of the deflection bias voltage, the radial position of the electrode head, and the density parameters, generate an adjustment command. The adjustment command is used to control the conduction direction and intensity of the radial current 4, and adjust the operating state and flow shear characteristics of the plasma circumferential rotation and polar rotation to the target requirements.

[0105] Specifically, the plasma density parameter is the core physical indicator affecting the radial conductivity of the plasma, and the conductivity directly determines the generation efficiency and conduction characteristics of the radial current 4. After obtaining these parameters, an adjustment command is generated by combining the polarity of the deflection bias voltage, the structural dimensions of the electrode head, the amplitude of the deflection bias voltage, the radial position of the electrode head, and the aforementioned density parameters. Among these parameters, the polarity of the deflection bias voltage directly determines the direction of charge directional movement in the plasma, and the structural dimensions of the electrode head (such as the 1cm radius and 0.5cm thickness of the electrode head adapted to CFQS in this invention) will affect the effective contact area between the electrode and the plasma, and thus be related to the amount of ion saturation current collected by formulas (6) and (7). The amplitude of the deflection bias voltage determines the magnitude of the radial potential difference, and the radial position of the electrode head matches the spatial asymmetry characteristics of the three-dimensional magnetic surface of the quasi-toroidal stellarator. The principle behind generating adjustment commands by integrating multi-dimensional parameters is to comprehensively match the conduction law of radial current 4 from aspects such as potential drive, contact interface, spatial adaptation, and plasma background characteristics. This allows the generated adjustment commands to specifically target and regulate radial current 4, precisely achieving controllable adjustment of its conduction direction and intensity. Taking the low-parameter (central magnetic field 0.1T) operation scenario of CFQS as an example, 5×10⁻⁶ Ω·cm of its edge plasma was obtained. 17 m -3 After obtaining the density parameters, and combining the applied positive bias polarity, the structural dimensions of the electrode head, the bias amplitude adapted to the device, and the radial position of the edge magnetic surface corresponding to window 46, an adjustment command adapted to the plasma characteristics of the region can be generated.

[0106] Furthermore, the core function of the generated adjustment command is to control the conduction direction and intensity of the radial current 4, thereby adjusting the operating state and flow shear characteristics of the plasma circumferential and polar rotation to the target requirements. The principle is that the Lorentz force generated by the interaction between the radial current 4 and the stellarator magnetic field is the core driving force for plasma rotation. The conduction direction and intensity of the current directly determine the direction and magnitude of the Lorentz force, thereby regulating the output characteristics of the circumferential and polar torques, and ultimately changing the operating state of the plasma circumferential and polar rotation. As can be seen from formula (9), the flow shear characteristics are determined by the radial gradient of the plasma circumferential rotation speed. The regulation of the current characteristics can indirectly change the gradient distribution. Thus, the closed-loop precise regulation of the plasma rotation state and flow shear characteristics is realized, solving the problem of the lack of active regulation means for plasma rotation in quasi-toroidal stellarators, and meeting the core requirements of CFQS for controllable and steady-state regulation of plasma rotation. The specific implementation method is as follows: This control process adjusts the radial electric field intensity and spatial distribution by adjusting the gradient distribution of the radial potential difference. The principle is that the gradient distribution of the radial potential difference is the direct physical basis for the formation of the radial electric field, and the change of the gradient distribution will directly affect the physical characteristics of the radial electric field. The plasma circumferential rotation velocity is determined by the interaction of the radial electric field and the poloidal magnetic field. Its shear rate is the radial variation rate of the circumferential rotation velocity. Through the aforementioned stepwise adjustments, the plasma circumferential rotation velocity and its shear rate can be precisely controlled, ultimately enabling the flow shear characteristics to meet the target requirement of suppressing plasma turbulence. This process relies on the core physical mechanism of magnetic confinement nuclear fusion. By stepwise controlling the potential difference, radial electric field, rotation velocity, and shear rate, precise suppression of plasma turbulence is achieved, thereby reducing plasma transport losses caused by turbulence, improving the plasma confinement performance of the CFQS quasi-toroidal stellarator, and adapting the experimental goal of suppressing magnetohydrodynamic instability and improving confinement performance. Taking CFQS as an example, by adjusting the command to increase the radial potential difference gradient in its edge magnetic surface region, the radial electric field intensity in this region is increased. Combined with the characteristics of the poloidal magnetic field in the region, the shear rate of the plasma circumferential rotation is increased, thus enabling the flow shear characteristics to meet the target requirement of suppressing plasma turbulence at the edge of the device.

[0107] Furthermore, after adjusting the operating states and flow shear characteristics of the plasma circumferential and polar rotation to the target requirements, the following steps are also included:

[0108] The closed-loop control mechanism for plasma rotation is established by first acquiring the radial displacement signal of the electrode head in real time using a grating displacement sensor. This process leverages the rigid connection between the grating displacement sensor and the external drive mechanism to directly convert the mechanical displacement signal of the electrode head into an electrical pulse signal. After counting and processing, the actual radial position information of the electrode head is accurately obtained. Simultaneously, the real-time electrical signal monitoring and acquisition function of the power supply module is used to synchronously acquire the actual bias voltage and current signals of the electrode head. The advantage of this approach is that it enables real-time monitoring of the electrode head's spatial position and electrical control signals across all dimensions, providing accurate and complete basic data for subsequent state determination. This avoids the limitations of single-signal monitoring and meets the real-time requirements of CFQS for plasma rotation control. For example, in the edge magnetic surface control corresponding to CFQS window 46, the grating displacement sensor can capture the micron-level radial displacement of the electrode head caused by plasma particle bombardment in real time, while the power supply module synchronously acquires the actual bias voltage and current signals of the electrode head in this state, providing complete data support for determining the control state.

[0109] Subsequently, the actual radial position information, actual bias signal, and actual current signal collected are quantitatively compared with the preset parameters in the adjustment command. The principle of this process is to accurately identify parameter deviations caused by three-dimensional magnetic field configuration fluctuations and changes in the plasma environment during plasma control through objective numerical comparison. Based on the deviation results obtained from the comparison, relying on the high positioning accuracy of the servo motor and the wide range of voltage and current output characteristics of the power supply module, the output parameters of the deflection bias and the radial position of the electrode head are dynamically adjusted. Its beneficial effect is to correct various parameter deviations in the control process in a timely manner and avoid the accumulation of deviations that cause the plasma rotation state to deviate from the target requirements. For example, when the CFQS is running at low parameters, if the actual bias signal is lower than the preset parameter, the power supply module can adjust the bias output amplitude in real time. If the actual position of the electrode head deviates from the preset magnetic surface, the servo motor can drive the push rod to complete the micro-displacement correction of the electrode head.

[0110] Example 2

[0111] Based on Example 1 and its control method, this embodiment provides a system for controlling plasma rotation, including:

[0112] The drive module includes a drive motor and an electrode head connected to the drive motor. The drive motor is fixed to the target window and is used to acquire the spatial positioning data of the target window and generate radial displacement control commands. In response to the radial displacement control commands, the drive motor drives the push rod to move the electrode head radially to the preset magnetic surface position of the plasma inside the quasi-annular stellarator.

[0113] The vacuum measurement module collects gas pressure data of the area where the electrode head is located through resistance gauge and ionization gauge, and generates a bias application command when the gas pressure data meets the preset vacuum conditions.

[0114] The power supply module includes a bias circuit. The power supply module is electrically connected to the electrode head via a transmission line. In response to a bias application command, the power supply module applies a deflection bias voltage to the electrode head located at a preset magnetic surface position via the transmission line to change the plasma potential of the magnetic surface where the electrode head is located. The outermost closed magnetic surface 1 is kept at ground potential due to contact with the limiter 3. The limiter 3 is installed in the vacuum chamber of the quasi-toroidal stellarator and grounded, forming a radial potential difference between the magnetic surface where the electrode head is located and the outermost closed magnetic surface 1.

[0115] The electrode head contacts the plasma and is electrically connected to the bias circuit of the power module via a transmission line. The limiter 3 and the bias circuit form a conductive path through the plasma, so that the electrode head, plasma, limiter 3 and bias circuit constitute a closed conductive loop. The closed conductive loop is used to generate a radial current 4 in the plasma between the magnetic surface where the electrode head is located and the outermost closed magnetic surface 1, and to generate a Lorentz force distribution based on the radial current 4 and the magnetic field data obtained from the stellarator. The Lorentz force distribution is used to construct a momentum source region in the plasma region between the magnetic surface where the electrode head is located and the outermost closed magnetic surface 1, so as to drive the plasma to generate circumferential rotation and poloidal rotation.

[0116] The adjustment module includes a grating displacement sensor connected to a drive motor for real-time acquisition of the radial displacement signal of the electrode head. The adjustment module also acquires plasma density parameters and obtains the polarity and amplitude of the deflection bias voltage from the power supply module. Based on the polarity of the deflection bias voltage, the structural dimensions of the electrode head, the amplitude of the deflection bias voltage, the radial position of the electrode head, and the density parameters, adjustment commands are generated. These adjustment commands control the conduction direction and intensity of the radial current 4, adjusting the plasma's circumferential and polar rotation operating states and flow shear characteristics to the target requirements.

[0117] Furthermore, such as Figure 3 As shown, the electrode head is integrally formed from a head 6 and a rod 5. The head 6 has a disc-shaped structure, and the rod 5 has a cylindrical structure. The diameter of the head 6 is larger than the diameter of the rod 5. The end face of the head 6 is flat and perpendicular to the axis of the rod 5 to increase the effective contact area between the electrode head and the plasma. The electrode head is made of graphite.

[0118] Furthermore, the head 6 of the electrode head is designed as a disc-shaped structure, and the rod 5 is designed as a cylindrical structure, with the diameter of the head 6 being larger than the diameter of the rod 5. This structural design is compatible with the collection principle of ion saturation current in the bias electrode system. The ion saturation current, as the maximum value constraint of the bias current, is positively correlated with the effective contact area between the electrode and the plasma. By enlarging the diameter of the head 6 to form a disc-shaped structure, the contact area between the electrode head and the plasma can be directly increased, thereby improving the collection amount of ion saturation current and providing a sufficient current basis for the stable generation of radial current 4. At the same time, the cylindrical rod 5 can reduce the contact resistance between the electrode head and the vacuum environment inside the stellarator during radial movement, ensuring the smoothness of the radial displacement of the electrode head. In addition, the end face of the head 6 is planar and perpendicular to the axis of the rod 5. This structural design allows the end face of the head 6 to form a uniform contact interface with the plasma, avoiding the problem of local uneven contact area caused by interface tilt, ensuring uniform and stable potential transfer between the plasma and the electrode head, and thus ensuring the uniform distribution of the radial electric field in the plasma region. Based on the calculation of the effective area of ​​the electrode in Example 1, after adopting the electrode shape in this example, the effective area of ​​the electrode in contact with the plasma is... It can be represented as:

[0119] (13)

[0120] In the formula, The radius of the electrode head. This refers to the thickness of the electrode head.

[0121] The electrode head is made of graphite. As a high-melting-point, low-atomic-number conductive material, graphite's physical properties perfectly match the requirements of stellarator electrodes. The low atomic number effectively reduces the impurity yield of the electrode material under plasma particle bombardment, preventing impurity elements from being released into the plasma and causing main plasma contamination and radiation loss. At the same time, graphite has good thermal shock resistance and high thermal conductivity, which can quickly conduct the heat generated by the interaction between the electrode head and the plasma, alleviating the electrode thermal load problem under long-pulse operation. In addition, the conductivity of graphite can ensure that the external deflection bias voltage is efficiently transferred to the plasma interior through the electrode head, realizing precise control of the plasma potential of the magnetic surface 2 where the electrode is located, and providing a stable potential transfer basis for the formation of radial potential difference and radial electric field.

[0122] It should be noted that the specific methods by which each module performs operations in the system described in the above embodiments have been described in detail in the embodiments related to the method, and will not be elaborated here.

[0123] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for controlling plasma rotation, characterized in that, include: Spatial positioning data of the target window of the target device is obtained by electronic digital sampling, and radial displacement control command is generated based on the spatial positioning data. According to the radial displacement control command, the electrode head is moved radially to the preset magnetic surface position of the plasma inside the target device; Gas pressure data of the area where the electrode head is located is obtained by electronic digital sampling, and a judgment is made by digital threshold comparison. When the gas pressure data meets the preset vacuum conditions, a bias application command is generated. According to the bias application command, a deflection bias is applied to the electrode head located at the preset magnetic surface position through the transmission line to change the plasma potential of the magnetic surface where the electrode head is located, so that the outermost closed magnetic surface remains at ground potential due to contact with the limiter on the target device, and a radial potential difference is formed between the magnetic surface where the electrode head is located and the outermost closed magnetic surface. Based on the radial potential difference, a radial electric field is induced in the plasma region between the magnetic surface where the electrode head is located and the outermost closed magnetic surface, and a radial current is generated in the plasma between the magnetic surface where the electrode head is located and the outermost closed magnetic surface through the closed conductive loop formed by the electrode head, the plasma, the limiter and the bias circuit. The magnetic field data within the target device is obtained by electrical digital sampling. The Lorentz force distribution is determined based on the radial current and the magnetic field data. The circumferential torque and the pole torque are generated based on the Lorentz force distribution. A momentum source region is constructed in the plasma region between the magnetic surface where the electrode head is located and the outermost closed magnetic surface to drive the plasma to generate circumferential rotation and pole rotation. The density parameters of the plasma are obtained, and an adjustment command is generated based on the polarity of the deflection bias voltage, the structural dimensions of the electrode head, the amplitude of the deflection bias voltage, the radial position of the electrode head, and the density parameters. The adjustment command is used to control the conduction direction and intensity of the radial current, and adjust the operating state and flow shear characteristics of the plasma circumferential rotation and polar rotation to the target requirements.

2. The method for controlling plasma rotation according to claim 1, characterized in that, The step of moving the electrode head radially to a preset magnetic surface position of the plasma inside the target device according to the radial displacement control command specifically includes: The three-dimensional magnetic field configuration data of the target device is acquired, the radial coordinate value corresponding to the preset magnetic surface position is extracted, and the radial coordinate value is converted into a rotation step control quantity for the drive motor. A pulse drive signal is generated based on the rotation step control quantity, and the electrode head is moved radially by the push rod driven by the servo motor. At the same time, the actual radial displacement of the electrode head is collected in real time by the grating displacement sensor. The actual radial displacement is compared with the radial coordinate value. When the comparison result meets the preset position deviation threshold, a position locking signal is generated to stop the drive of the servo motor.

3. The method for controlling plasma rotation according to claim 1, characterized in that, The step of generating a bias application command when the gas pressure data meets the preset vacuum conditions specifically includes: Gas pressure data after vacuum connection is collected using resistance gauges and ionization gauges; the gas pressure data is compared with the pressure standard corresponding to the preset vacuum condition; when the gas pressure data meets the preset pressure standard, it is determined that the vacuum condition is met, and a bias pressure application command is generated.

4. The method for controlling plasma rotation according to claim 1, characterized in that, The closed conductive loop formed by the electrode head, plasma, limiter, and bias circuit generates a radial current in the plasma between the magnetic surface where the electrode head is located and the outermost closed magnetic surface, specifically including: According to the bias application command, the power module applies a deflection bias to the electrode head through the transmission line, forming a bias current in the closed conductive loop formed by the electrode head, plasma, limiter and bias circuit. Obtain the magnetic surface area of ​​the magnetic surface where the electrode head is located, the large radius of the magnetic surface where the electrode head is located, and the small radius of the magnetic surface where the electrode head is located; The current density of the radial current is determined based on the bias current, the magnetic surface area, the large radius, and the small radius; based on the current density, a radial current is formed in the plasma region between the magnetic surface where the electrode head is located and the outermost closed magnetic surface.

5. The method for controlling plasma rotation according to claim 4, characterized in that, The bias current is obtained using the following formula: In the formula, This is the bias current; The magnetic surface area of ​​the magnetic surface where the electrode head is located; The current density is the radial current. The large radius at the magnetic surface where the electrode head is located; It is the small radius at the magnetic surface where the electrode head is located.

6. The method for controlling plasma rotation according to claim 1, characterized in that, The adjustment of the plasma's circumferential and polar rotation operating states and flow shear characteristics to the target requirements specifically includes: By adjusting the gradient distribution of the radial potential difference, the intensity and spatial distribution of the radial electric field, and the plasma circumferential rotation speed and shear rate determined by the radial electric field and the poloidal magnetic field, the flow shear characteristics can achieve the target requirement of suppressing plasma turbulence.

7. The method for controlling plasma rotation according to claim 1, characterized in that, After adjusting the plasma circumferential and polar rotation operating states and flow shear characteristics to the target requirements, the process also includes: The radial displacement signal of the electrode head is acquired in real time by a grating displacement sensor. The radial displacement signal is converted into an electrical pulse signal and processed to obtain the actual radial position information of the electrode head. At the same time, the actual bias voltage signal and actual current signal of the electrode head are acquired in real time by a power supply module. The actual radial position information, actual bias voltage signal, and actual current signal are compared with the preset parameters of the adjustment command. Based on the comparison results, the output parameters of the deflection bias voltage and the radial position of the electrode head are dynamically adjusted to maintain the plasma rotation state and flow shear characteristics at the target requirements, thereby achieving closed-loop control of the plasma rotation state.

8. A system for controlling plasma rotation, based on the method for controlling plasma rotation according to claim 1, characterized in that, include: A drive module, the drive module including a drive motor and an electrode head connected to the drive motor via a push rod; The drive motor is fixed to the target window and is used to acquire the spatial positioning data of the target window flange and generate a radial displacement control command. In response to the radial displacement control command, the drive motor drives the push rod to move the electrode head radially to the preset magnetic surface position of the plasma inside the target device. The vacuum measurement module collects gas pressure data of the area where the electrode head is located through a resistance gauge and an ionization gauge, and generates a bias application command when the gas pressure data meets the preset vacuum conditions. A power module, including a bias circuit, is electrically connected to the electrode head via a transmission line. In response to a bias application command, the power module applies a deflection bias to the electrode head located at a preset magnetic surface position via the transmission line to change the plasma potential of the magnetic surface where the electrode head is located. The outermost closed magnetic surface remains grounded due to contact with a limiter, which is installed in the vacuum chamber of the target device and grounded, creating a radial potential difference between the magnetic surface where the electrode head is located and the outermost closed magnetic surface. The electrode head is in contact with the plasma, and the electrode head is electrically connected to the bias circuit of the power module through the transmission line. The limiter and the bias circuit form a conductive path through the plasma, so that the electrode head, the plasma, the limiter, and the bias circuit constitute a closed conductive loop. The closed conductive loop is used to generate a radial current in the plasma between the magnetic surface where the electrode head is located and the outermost closed magnetic surface, and to generate a Lorentz force distribution based on the radial current and the magnetic field data obtained from the target device. The Lorentz force distribution is used to construct a momentum source region in the plasma region between the magnetic surface where the electrode head is located and the outermost closed magnetic surface, so as to drive the plasma to generate circumferential rotation and poloidal rotation. An adjustment module includes a grating displacement sensor connected to the drive motor for real-time acquisition of the radial displacement signal of the electrode head. The adjustment module also acquires the plasma density parameter and obtains the polarity and amplitude of the deflection bias voltage from the power supply module. Based on the polarity of the deflection bias voltage, the structural dimensions of the electrode head, the amplitude of the deflection bias voltage, the radial position of the electrode head, and the density parameter, an adjustment command is generated. This adjustment command controls the conduction direction and intensity of the radial current, adjusting the plasma's circumferential and polar rotation operating states and flow shear characteristics to the target requirements.

9. A system for controlling plasma rotation according to claim 8, characterized in that, The electrode head is integrally formed from a head and a rod. The head has a disc-shaped structure, and the rod has a cylindrical structure. The diameter of the head is larger than the diameter of the rod. The end face of the head is flat and perpendicular to the axis of the rod, so as to increase the effective contact area between the electrode head and the plasma.

10. A system for controlling plasma rotation according to claim 8, characterized in that, The electrode head is made of graphite.

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