A method and system for langmuir probe detection

Abstract

The application discloses a Langmuir probe detection method and system, and relates to the technical field of plasma detection; the application is improved on the basis of the existing Langmuir probe detection method; in the process of detecting plasma by using three probes in a three-probe mode, the working state of the three probes is monitored in real time to determine whether the working state is abnormal; the measurement mode of each probe is switched according to the abnormal working state of the three probes, so that the probe with a normal working state can continuously detect; when some probes are damaged due to plasma ablation or other reasons, the remaining probes can still measure the plasma parameters as much as possible, and resource waste is avoided.

Description

Technical Field

[0001] This invention relates to the field of plasma detection technology, specifically to a Langmuir probe detection method and system. Background Technology

[0002] The Langmuir probe is a basic plasma diagnostic tool used to measure fundamental parameters of plasma, such as saturated ion current, electron temperature, ion density, levitation potential, and plasma potential. Depending on the parameters being measured, the Langmuir probe has different measurement circuit modes.

[0003] The Langmuir probe is a basic plasma diagnostic tool used to measure fundamental parameters of plasma, such as saturated ion current, electron temperature, ion density, levitation potential, and plasma potential. Depending on the parameters being measured, the Langmuir probe has different measurement circuit modes.

[0004] Single-probe mode: By applying a constant negative bias voltage to ground on the probe, an ion sheath forms on the probe surface, repelling electrons and attracting ions. When the bias voltage is high enough, the probe current saturates; this current is the saturation ion current I. si .

[0005] Dual-probe mode: A constant bias voltage is applied between the two probes, placing one probe in the ion saturation region and the other in the transition region. The voltages relative to ground of the two probes are measured as V+ and V-, respectively, and the plasma saturated ion current I can also be measured. si .

[0006] Suspended potential probe mode: The probe is suspended in the plasma, and its potential relative to ground is the suspension potential V. f ;

[0007] Three-probe mode: The three-probe mode is a direct combination of the two-probe mode and the floating potential probe mode, i.e., two probes are in two-probe mode, and the third probe is in floating potential probe mode. Based on the probe principle, combined with the effective measurement area S of the probe and the ion sound velocity C... s The parameters related to plasma and electrostatics can be calculated as follows: Electron temperature: density Plasma potential V p =V f +αT e α is the sheath potential drop coefficient, which is determined by both plasma characteristics and probe material;

[0008] In practice, the three-probe mode is widely used because it provides more comprehensive measurement parameters. However, if one of the probes is damaged due to plasma ablation or other reasons, the remaining probes, even if intact, will become unusable. Summary of the Invention

[0009] The technical problem this invention aims to solve is that in practical applications of the three-probe mode, when one probe is damaged due to plasma ablation or other reasons, the remaining probes, even if intact, cannot be used, wasting detection resources. The purpose of this invention is to provide a Langmuir probe detection method and system that, during plasma detection in three-probe mode, monitors the operational status of the three probes in real time to detect any abnormalities. Based on the abnormality, the measurement mode of each probe is switched, allowing probes in normal working condition to continue detection. Even when some probes are damaged due to plasma ablation or other reasons, the remaining probes can still measure plasma parameters as much as possible, avoiding resource waste.

[0010] This invention is achieved through the following technical solution:

[0011] This invention provides a Langmuir probe detection method, which is applied to the Langmuir probe in a three-probe mode. The three-probe mode includes the following measurement modes: single-probe measurement mode, dual-probe measurement mode, floating potential probe measurement mode, and three-probe measurement mode.

[0012] The method includes:

[0013] Step 1: Detect plasma using a three-probe array and monitor the operational status of the three probes in real time to check for any abnormalities.

[0014] Step 2: Switch the measurement mode of each probe according to the abnormal working status of the three probes, so that the probes with normal working status can continue to detect.

[0015] The working principle of this solution: In practical applications of the three-probe mode, when one probe is damaged due to plasma ablation or other reasons, the remaining probes, even if intact, cannot be used, resulting in a waste of detection resources. The purpose of this invention is to provide a Langmuir probe detection method and system, which improves upon existing Langmuir probe detection methods. During plasma detection using the three-probe mode, the system monitors the working status of the three probes in real time for any abnormalities. Based on the abnormality, it switches the measurement mode of each probe, allowing probes in normal working condition to continue detection. Even when some probes are damaged due to plasma ablation or other reasons, the remaining probes can still measure plasma parameters as much as possible, avoiding resource waste.

[0016] The further optimized solution includes, in step two:

[0017] When an abnormality is detected in one of the three probes, at least one of the remaining two probes will be switched to single-probe measurement mode.

[0018] When two of the three probes are detected to be in abnormal working condition, the remaining probe will be switched to single probe measurement mode.

[0019] If all three probes are detected to be in abnormal working condition, do not switch.

[0020] A further optimization scheme is to switch one of the three probes to single-probe measurement mode and the other probe to floating potential probe measurement mode when an abnormality is detected.

[0021] This solution also provides a Langmuir probe detection system for implementing the above-mentioned Langmuir probe detection method, including:

[0022] The monitoring module is used to detect plasma based on the three probes and monitor the working status of the three probes in real time to see if there are any abnormalities.

[0023] The switching module is used to switch the measurement mode of each probe according to the abnormal working status of the three probes, so that the probes in normal working status can continue to detect.

[0024] A further optimized solution is that the switching module includes a switching circuit, which includes a first relay, a second relay, a third relay, and a fourth relay.

[0025] The negative terminal of the power supply is connected to the moving contact of the first relay, the first stationary contact of the first relay is connected to the first probe, and the second stationary contact of the first relay is grounded.

[0026] The positive terminal of the power supply is connected to the first stationary contact of the second relay, and the moving contact of the second relay is connected to the second probe.

[0027] The positive terminal of the power supply is also connected to the first stationary contact of the third relay, and the moving contact of the third relay is connected to the first probe.

[0028] The positive terminal of the power supply is also connected to the first stationary contact of the fourth relay, the second stationary contact of the fourth relay is grounded, and the moving contact of the fourth relay is connected to the third probe. The first, second, and third probes are all in contact with the plasma.

[0029] A further optimization scheme is proposed, which includes the following operating modes for the switching circuit:

[0030] When the moving contact of the first relay is connected to the second stationary contact of the first relay, the moving contact of the second relay is connected to the second stationary contact of the second relay, the moving contact of the third relay is connected to the second stationary contact of the third relay, and the moving contact of the fourth relay is connected to the second stationary contact of the fourth relay, it is the switching circuit not powered on mode.

[0031] Mode 1: When the moving contact of the first relay is connected to the first stationary contact of the first relay, the moving contact of the second relay is connected to the first stationary contact of the second relay, the moving contact of the third relay is connected to the second stationary contact of the third relay, and the moving contact of the fourth relay is connected to the second stationary contact of the fourth relay, the first and second probes operate in dual-probe measurement mode, and the third probe operates in floating probe measurement mode; when all three probes are undamaged, it can operate in the current mode.

[0032] Mode 2: When the moving contact of the first relay is connected to the second stationary contact of the first relay, the moving contact of the second relay is connected to the first stationary contact of the second relay, the moving contact of the third relay is connected to the second stationary contact of the third relay, and the moving contact of the fourth relay is connected to the second stationary contact of the fourth relay, the second probe operates in single-probe measurement mode, and the third probe operates in suspended probe measurement mode. If the first probe is damaged, it can operate in the current mode.

[0033] A further optimization solution is to switch the circuit's operating mode as follows:

[0034] When the first probe malfunctions, the switch is not performed; the second probe operates in single probe measurement mode, and the third probe operates in suspended probe measurement mode.

[0035] When the second probe malfunctions, the moving contact of the second relay is switched to the second stationary contact of the second relay, and the moving contact of the third relay is switched to the first stationary contact of the third relay, so that the first probe works in single probe mode and the third probe works in floating probe measurement mode.

[0036] A further optimization solution is to switch the circuit to operating mode two as follows:

[0037] When the third probe is damaged, the switch is not performed; the second probe operates in single-probe measurement mode.

[0038] When the first and third probes are damaged, the switch is not performed; the second probe operates in single-probe measurement mode.

[0039] A further optimization scheme is as follows: when the first and second probes are damaged, the moving contact of the first relay is connected to the second stationary contact of the first relay, the moving contact of the second relay is connected to the second stationary contact of the second relay, the moving contact of the third relay is connected to the second stationary contact of the third relay, and the moving contact of the fourth relay is connected to the first stationary contact of the fourth relay, so that the third probe can work in the suspended probe measurement mode.

[0040] A further optimization scheme is as follows: when the second and third probes are damaged, the moving contact of the first relay is connected to the second stationary contact of the first relay, the moving contact of the second relay is connected to the second stationary contact of the second relay, the moving contact of the third relay is connected to the first stationary contact of the third relay, and the moving contact of the fourth relay is connected to the second stationary contact of the fourth relay, so that the third probe can work in single-probe measurement mode.

[0041] The switching circuit provided by this invention enables remote switching between three-probe circuit measurement mode, single-probe circuit measurement mode, and floating potential probe circuit measurement mode. When one of the three probes is damaged, the remaining two probes can be switched to single-probe circuit and floating potential probe circuit respectively. When two of the three probes are damaged, the remaining probe can be switched to single-probe circuit, so that the probes in normal working condition can continue to work in other modes, making it convenient for the testing personnel to continue to obtain relevant plasma parameters.

[0042] This solution applies the Langmuir probe detection system to the operation of the future fusion reactor, including: the future fusion reactor, the remote control module, and the aforementioned Langmuir probe detection system;

[0043] The remote control module is wirelessly connected to the switching module, and the remote control module remotely controls the switching module.

[0044] The monitoring module is installed inside the future fusion reactor and will perform plasma detection during the operation of the future fusion reactor.

[0045] In long-pulse magnetic confinement fusion research or future fusion reactor operation, the operating discharge time is measured in tens of minutes or even hours. During the operating discharge, if one or two detection channels of the electrostatic probe three-probe system malfunction, circuit switching and repair cannot be performed before the discharge ends. In this case, the electrostatic probe three-probe system will lose all data after the malfunction. However, this solution, through the Langmuir probe detection system, allows for configuration circuit switching during operation of the malfunctioning three-probe system, preserving the measurement capability of some data.

[0046] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0047] This invention provides a Langmuir probe detection method and system, which improves upon existing Langmuir probe detection methods. During plasma detection using a three-probe system in three-probe mode, the system monitors the operational status of the three probes in real time to identify any abnormalities. Based on these abnormalities, the system switches the measurement mode of each probe, ensuring continuous detection by probes in normal working order. Even when some probes are damaged due to plasma ablation or other reasons, the remaining probes can still measure plasma parameters as much as possible, avoiding resource waste. Attached Figure Description

[0048] To more clearly illustrate the technical solutions of the exemplary embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly described below. It should be understood that the following drawings only show some embodiments of the present invention and should not be considered as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort. In the drawings:

[0049] Figure 1 This is a schematic diagram of the Langmuir probe detection method.

[0050] Figure 2 This is a schematic diagram of the circuit structure for the switching circuit in the power-off mode.

[0051] Figure 3 This is a schematic diagram of the circuit structure for switching circuit modes.

[0052] Figure 4 This is a schematic diagram of the circuit structure for switching circuit mode two;

[0053] Figure 5 A schematic diagram of the circuit structure where the first probe is in single-probe mode and the third probe is in floating probe mode;

[0054] Figure 6 This is a schematic diagram of the circuit structure where the second probe is in single-probe mode.

[0055] Figure 7 This is a schematic diagram of the circuit structure where the third probe is in single-probe mode.

[0056] Figure 8 This is a schematic diagram of the circuit structure where the first probe is in single-probe mode. Detailed Implementation

[0057] To make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the embodiments and accompanying drawings. The illustrative embodiments and descriptions of the present invention are only used to explain the present invention and are not intended to limit the present invention.

[0058] Example 1

[0059] This invention provides a Langmuir probe detection method, which is applied to the Langmuir probe in a three-probe mode. The three-probe mode includes the following measurement modes: single-probe measurement mode, dual-probe measurement mode, floating potential probe measurement mode, and three-probe measurement mode.

[0060] like Figure 1 As shown, the method includes:

[0061] Step 1: Detect plasma using a three-probe array and monitor the operational status of the three probes in real time to check for any abnormalities.

[0062] Step Two: Switch the measurement mode of each probe according to the abnormal working status of the three probes, so that the probes with normal working status can continue to detect. Step Two specifically includes:

[0063] When an abnormality is detected in one of the three probes, at least one of the remaining two probes will be switched to single-probe measurement mode; alternatively, one of the remaining probes can be switched to single-probe measurement mode, and the other probe can be switched to floating potential probe measurement mode.

[0064] When two of the three probes are detected to be in abnormal working condition, the remaining probe will be switched to single probe measurement mode.

[0065] If all three probes are detected to be in abnormal working condition, do not switch.

[0066] Example 2

[0067] This solution also provides a Langmuir probe detection system for implementing the Langmuir probe detection method of Example 1, including:

[0068] The monitoring module is used to detect plasma based on the three probes and monitor the working status of the three probes in real time to see if there are any abnormalities.

[0069] The switching module is used to switch the measurement mode of each probe according to the abnormal working status of the three probes, so that the probes in normal working status can continue to detect.

[0070] Example 3

[0071] Based on the previous embodiment, the switching module in this embodiment includes a switching circuit, such as... Figure 2 As shown, the switching circuit includes: Power, first relay S1, second relay S2, third relay S3 and fourth relay S4;

[0072] The negative terminal of the power supply is connected to the moving contact 2 of the first relay S1, the first stationary contact 1 of the first relay S1 is connected to the first probe Probe1, and the second stationary contact 3 of the first relay S1 is grounded.

[0073] The positive terminal of the power supply is connected to the first stationary contact 1 of the second relay, and the moving contact of the second relay S2 is connected to the second probe Probe2.

[0074] The positive terminal of the power supply is also connected to the first stationary contact 1 of the third relay S3, and the moving contact 2 of the third relay S3 is connected to the first probe Probe1.

[0075] The positive terminal of the power supply is also connected to the first stationary contact 1 of the fourth relay S4, the second stationary contact 3 of the fourth relay S4 is grounded, and the moving contact 2 of the fourth relay S4 is connected to the third probe Probe 3. The first probe Probe 1, the second probe Probe 2, and the third probe Probe 3 are all in contact with the plasma.

[0076] The operating modes of the switching circuit include:

[0077] like Figure 2 As shown, when the moving contact 2 of the first relay S1 is connected to the second stationary contact 3 of the first relay S1, the moving contact 2 of the second relay S2 is connected to the second stationary contact 3 of the second relay S2, the moving contact 2 of the third relay S3 is connected to the second stationary contact 3 of the third relay S3, and the moving contact 2 of the fourth relay S4 is connected to the second stationary contact 3 of the fourth relay S4, it is the switching circuit not powered on mode.

[0078] like Figure 3 As shown; Mode 1: When the moving contact 2 of the first relay S1 is connected to the first stationary contact 1 of the first relay S1, the moving contact 2 of the second relay S2 is connected to the first stationary contact 1 of the second relay S2, the moving contact 2 of the third relay S3 is connected to the second stationary contact 3 of the third relay S3, and the moving contact 2 of the fourth relay S4 is connected to the second stationary contact 3 of the fourth relay S4, the first probe Probe1 and the second probe Probe2 work in the dual probe measurement mode, and the third probe Probe3 works in the floating probe measurement mode.

[0079] like Figure 4 As shown; Mode 2: When the moving contact 2 of the first relay S1 is connected to the second stationary contact 3 of the first relay S1, the moving contact 2 of the second relay S2 is connected to the first stationary contact 1 of the second relay S2, the moving contact 2 of the third relay S3 is connected to the second stationary contact 3 of the third relay S3, and the moving contact 2 of the fourth relay S4 is connected to the second stationary contact 3 of the fourth relay S4, the second probe Probe2 works in single probe measurement mode, and the third probe Probe3 works in floating probe measurement mode.

[0080] like Figure 4 As shown, the operating mode of the switching circuit is as follows:

[0081] When the first probe Probe1 malfunctions, it does not switch; the second probe Probe2 operates in single probe measurement mode, and the third probe Probe3 operates in suspended probe measurement mode.

[0082] like Figure 5As shown, when the second probe Probe2 malfunctions, the moving contact 2 of the second relay S2 is switched to the second stationary contact 3 of the second relay S2, and the moving contact 2 of the third relay S3 is switched to the first stationary contact 1 of the third relay S3, so that the first probe Probe1 works in single probe mode and the third probe Probe3 works in floating probe measurement mode.

[0083] like Figure 6 As shown, in the second operating mode of the switching circuit:

[0084] When the third probe Probe3 is damaged, it will not switch; thus enabling the second probe Probe2 to work in single-probe measurement mode.

[0085] When the first probe Probe1 and the third probe Probe3 are damaged, the switching does not occur; thus, the second probe Probe2 operates in single-probe measurement mode.

[0086] like Figure 7 As shown, when the first probe Probe1 and the second probe Probe2 are damaged, the moving contact 2 of the first relay S1 is connected to the second stationary contact 3 of the first relay S1, the moving contact 2 of the second relay S2 is connected to the second stationary contact 3 of the second relay S2, the moving contact 2 of the third relay S3 is connected to the second stationary contact 3 of the third relay S3, and the moving contact 2 of the fourth relay S4 is connected to the first stationary contact 1 of the fourth relay S4, so that the third probe Probe3 can work in the floating probe measurement mode.

[0087] like Figure 8 As shown, when the second probe Probe2 and the third probe Probe3 are damaged, the moving contact 2 of the first relay S1 is connected to the second stationary contact 3 of the first relay S1, the moving contact 2 of the second relay S2 is connected to the second stationary contact 3 of the second relay S2, the moving contact 2 of the third relay S3 is connected to the first stationary contact 1 of the third relay S3, and the moving contact 2 of the fourth relay S4 is connected to the second stationary contact 3 of the fourth relay S4, so that the first probe Probe1 can work in single probe measurement mode.

[0088] The above embodiments enable remote control of switching between different measurement circuit modes for the three probes. In the event of damage to some of the three probes, the measurement circuit mode for the undamaged probes can be switched by controlling a relay.

[0089] Example 4

[0090] This embodiment also provides an application of the Langmuir probe detection system, including: a future fusion reactor, a remote control module, and the Langmuir probe detection system in the above embodiment;

[0091] The remote control module is wirelessly connected to the switching module, and the remote control module remotely controls the switching module.

[0092] The monitoring module is installed inside the future fusion reactor and will perform plasma detection during the operation of the future fusion reactor.

[0093] In long-pulse magnetic confinement fusion research or future fusion reactor operation, the operating discharge time is measured in tens of minutes or even hours. During the operating discharge, if one or two detection paths of the electrostatic probe three-probe system fail, circuit switching and repair cannot be performed before the discharge ends. In this case, the electrostatic probe three-probe system will lose all data after the failure. However, this solution, through the Langmuir probe detection system, allows for configuration circuit switching during operation of the faulty three-probe system, preserving the measurement capability of some data.

[0094] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. 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 Langmuir probe detection system, wherein the Langmuir probe measurement modes include: The system includes single-probe measurement mode, dual-probe measurement mode, floating potential probe measurement mode, and triple-probe measurement mode; its characteristic is that the system is used to implement the Langmuir probe detection method. The method includes: Step 1: Detect plasma using a three-probe array and monitor its operational status in real time for any abnormalities. Step 2: Switch the measurement mode of each probe according to the abnormal working status of the three probes, so that the probes with normal working status can continue to detect. Step two includes: When an abnormality is detected in one of the three probes, at least one of the remaining two probes will be switched to single-probe measurement mode. When two of the three probes are detected to be in abnormal working condition, the remaining probe will be switched to single probe measurement mode. Do not switch when all three probes are detected to be in abnormal working condition; When an abnormality is detected in one of the three probes, the remaining probe is switched to single probe measurement mode, and the other probe is switched to floating potential probe measurement mode. The system includes: The monitoring module is used to detect plasma based on the three probes and monitor the working status of the three probes in real time to see if there are any abnormalities. The switching module is used to switch the measurement mode of each probe according to the abnormal working status of the three probes, so that the probes with normal working status can continue to detect. The switching module includes a switching circuit, which includes a first relay, a second relay, a third relay, and a fourth relay. The negative terminal of the power supply is connected to the moving contact of the first relay, the first stationary contact of the first relay is connected to the first probe, and the second stationary contact of the first relay is grounded. The positive terminal of the power supply is connected to the first stationary contact of the second relay, and the moving contact of the second relay is connected to the second probe. The positive terminal of the power supply is also connected to the first stationary contact of the third relay, and the moving contact of the third relay is connected to the first probe. The positive terminal of the power supply is also connected to the first stationary contact of the fourth relay, the second stationary contact of the fourth relay is grounded, and the moving contact of the fourth relay is connected to the third probe. The switching circuit includes operating modes: When the moving contact of the first relay is connected to the second stationary contact of the first relay, the moving contact of the second relay is connected to the second stationary contact of the second relay, the moving contact of the third relay is connected to the second stationary contact of the third relay, and the moving contact of the fourth relay is connected to the second stationary contact of the fourth relay, it is the switching circuit not powered on mode. Mode 1: When the moving contact of the first relay is connected to the first stationary contact of the first relay, the moving contact of the second relay is connected to the first stationary contact of the second relay, the moving contact of the third relay is connected to the second stationary contact of the third relay, and the moving contact of the fourth relay is connected to the second stationary contact of the fourth relay, the first probe and the second probe work in the dual probe measurement mode, and the third probe works in the floating probe measurement mode. Mode 2: When the moving contact of the first relay is connected to the second stationary contact of the first relay, the moving contact of the second relay is connected to the first stationary contact of the second relay, the moving contact of the third relay is connected to the second stationary contact of the third relay, and the moving contact of the fourth relay is connected to the second stationary contact of the fourth relay, the second probe operates in single probe measurement mode and the third probe operates in floating probe measurement mode. The switching circuit also includes an operating mode: When the moving contact of the first relay is connected to the second stationary contact of the first relay, the moving contact of the second relay is connected to the second stationary contact of the second relay, the moving contact of the third relay is connected to the first stationary contact of the third relay, and the moving contact of the fourth relay is connected to the second stationary contact of the fourth relay, the third probe is made to work in single probe measurement mode. Switch the circuit's operating mode as follows: Switch the moving contact of the second relay to the second stationary contact of the second relay, and switch the moving contact of the third relay to the first stationary contact of the third relay, so that the first probe works in single probe mode and the third probe works in floating probe measurement mode. The switching circuit also includes an operating mode: When the moving contact of the first relay is connected to the second stationary contact of the first relay, the moving contact of the second relay is connected to the second stationary contact of the second relay, the moving contact of the third relay is connected to the second stationary contact of the third relay, and the moving contact of the fourth relay is connected to the first stationary contact of the fourth relay, the third probe is put into operation in the suspended probe measurement mode.

2. The Langmuir probe detection system according to claim 1, characterized in that, The system is applied to the operation of the future fusion reactor and also includes the future fusion reactor and a remote control module; The remote control module is wirelessly connected to the switching module, and the remote control module remotely controls the switching module. The monitoring module is installed inside the future fusion reactor and will perform plasma detection during the operation of the future fusion reactor.

3. The Langmuir probe detection system according to claim 1, characterized in that, The first probe, the second probe, and the third probe are all in contact with the plasma.

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