A dual-channel ion energy probe based on magnetic deflection effect

Abstract

The application relates to the technical field of plasma detection, in particular to a double-channel ion energy probe based on a magnetic deflection effect. The application provides a double-channel ion energy probe based on a magnetic deflection effect, which comprises an upper permanent magnet plate, a lower permanent magnet plate, a double-channel collimator and a double-channel probe; the double-channel collimator penetrates into a shell; the double-channel collimator comprises a scanning channel and a reference channel; the scanning channel and the reference channel are connected with different values of voltage; the double-channel collimator is used for enabling ions to enter the shell along the channel direction; the upper permanent magnet plate and the lower permanent magnet plate are fixed at the upper and lower ends of the shell respectively so as to form a uniform magnetic field; the double-channel probe is arranged in the shell and comprises a scanning collection probe and a reference collection probe which are respectively coplanar with the scanning channel and the reference channel; and the scanning collection probe and the reference collection probe are respectively connected with different values of voltage. The scheme can provide an ion current probe with high signal-to-noise ratio.

Description

Technical Field

[0001] This invention relates to the field of plasma detection technology, and in particular to a dual-channel ion energy probe based on the magnetic deflection effect. Background Technology

[0002] Plasma probes can be widely used in plume studies and rapid acquisition of ion parameters under high vacuum conditions such as ion thrusters, Hall thrusters, and magnetohydrodynamic thrusters. They are particularly suitable for ion flow measurement and energy spectrum analysis under pulsed discharge, unsteady excitation, or high-frequency disturbance environments.

[0003] These probes are primarily used to obtain key parameters such as the energy distribution function of ions in the thruster plume and the current intensity of ions in different valence states, thereby providing crucial data support for the design optimization, performance evaluation, and on-orbit verification of ion electric thrusters. However, existing ion probes suffer from low signal-to-noise ratios during detection, making it difficult to measure the distribution of ions at different energy levels within the ion stream. Summary of the Invention

[0004] This invention provides a dual-channel ion energy probe based on magnetic deflection effect, which can provide an ion current probe with a high signal-to-noise ratio.

[0005] This invention provides a dual-channel ion energy probe based on magnetic deflection effect, comprising an upper permanent magnet plate, a lower permanent magnet plate, a dual-channel collimator, and a dual-channel probe;

[0006] The dual-channel collimator extends into the housing and includes a scanning channel and a reference channel. The scanning channel and the reference channel are connected to voltages of different values. The dual-channel collimator is used to allow ions to enter the housing along the channel direction. The upper permanent magnet plate and the lower permanent magnet plate are fixed at the upper and lower ends of the housing, respectively, to form a uniform magnetic field. The dual-channel probe is disposed in the housing and includes a scanning collection probe coplanar with the scanning channel and a reference collection probe coplanar with the reference channel. The scanning collection probe and the reference collection probe are connected to voltages of different values.

[0007] In one possible design, both channels of the dual-channel collimator are arranged perpendicular to the direction of the magnetic field, and two side electrode plates are arranged perpendicular to the direction of the dual-channel collimator and the direction of the magnetic field to form an electric field between the two side electrode plates.

[0008] In one possible design, both the scanning channel and the reference channel include a measurement channel inlet, a measurement channel outlet, a ceramic tube, and a shielding sleeve. The measurement channel inlet and the measurement channel outlet are respectively located at both ends of the ceramic tube, and the shielding sleeve is located outside the ceramic tube.

[0009] In one possible design, the receiving end of the dual-channel probe is located on the surface of maximum ion current dispersion, with the receiving end facing the outlet direction of the dual-channel collimator.

[0010] In one possible design, the scanning collection probe and the reference collection probe are connected to a drive device via a transmission arm, the drive device being used to drive the scanning collection probe and the reference collection probe to move within the surface of maximum ion current dispersion.

[0011] In one possible design, the drive device includes a stepper motor, a transmission gear, a slider, a lead screw, and a slide rail. The output end of the stepper motor drives the lead screw through the transmission gear. The lead screw and the slide rail pass through the slider, and the slider is fixedly connected to the transmission arm.

[0012] In one possible design, the scanning collection probe and the reference collection probe share a shielding shell. Both the scanning collection probe and the reference collection probe include a shielding barrel and a collection probe mounted on the shielding shell. The scanning collection probe and the reference collection probe are respectively disposed in two shielding barrels and do not contact the shielding barrels. One end of the shielding barrel is mounted on the shielding shell, and the shielding shell is connected to the transmission arm.

[0013] In one possible design, the side electrode plate is fixed to the housing by insulating posts.

[0014] In one possible design, the voltage difference between the scan channel and the reference channel is 0.5V, and the voltage difference between the scan collection probe and the reference collection probe is 0.5V.

[0015] Compared with the prior art, the present invention has at least the following beneficial effects:

[0016] 1. Significantly improved signal-to-noise ratio: Ion energy separation is achieved through magnetic field deflection, avoiding electronic interference noise caused by high-voltage grids; dual-channel differential measurement effectively suppresses environmental noise, and the signal-to-noise ratio is several times higher than that of traditional methods, so even weak ion currents can be reliably detected.

[0017] 2. Rich functionality and comprehensive information: This system can acquire ion energy distribution curves in near real-time, obtaining complete energy spectrum information in a single measurement, providing rich data support for thruster performance analysis. Compared to traditional probes that only provide total current or average energy information, this invention outputs detailed transient energy spectrum distribution, providing valuable data for in-depth research on thruster operating conditions and efficiency optimization.

[0018] 3. High practicality and reliability: The system uses a single constant voltage power supply to generate an electrostatic field, and a permanent magnet plate generates a constant magnetic field, eliminating the need for multiple power supply linkages and ensuring a simple and reliable electrical configuration. The absence of high-voltage scanning components reduces the risk of failure, and the optimized mechanical scanning mechanism guarantees positioning accuracy and repeatability. The probe assembly has low alignment requirements, facilitating assembly and maintenance. The system can operate stably for extended periods in thruster testing environments, is not easily affected by external interference, and provides measurement results with excellent repeatability.

[0019] 4. Broad Application Prospects: Although this invention is designed for plume diagnosis of micro electric thrusters, its principles and devices can be extended to other high-energy ion beam energy spectrum measurement applications. For example, it can be used in commercial satellite electric propulsion, deep space exploration thruster testing, and various ion source research fields to quickly obtain energy distribution information of high-energy ion beams, providing crucial support for thruster performance optimization and efficiency improvement. Due to its compact structure, reliability, and durability, this system has broad application potential in spacecraft on-orbit monitoring, laboratory research, and other applications. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 This is a schematic diagram of a probe structure provided in an embodiment of the present invention;

[0022] Figure 2 The diagram shows the separation trajectory distribution of Xe ions with different energies due to differences in cyclotron radius under a magnetic field strength of 0.5T.

[0023] Figure 3 This is a top-view schematic diagram of an ion trajectory under a superimposed electric field provided in an embodiment of the present invention;

[0024] Figure 4 This is a schematic diagram of an ion trajectory under a superimposed electric field provided in an embodiment of the present invention;

[0025] Figure 5 This is a schematic diagram of the structure of a dual-channel collimator provided in an embodiment of the present invention;

[0026] Figure 6 This is a schematic diagram of a dual-channel probe provided in an embodiment of the present invention.

[0027] In the diagram, 1. Dual-channel collimator; 11. Measurement channel inlet; 12. Measurement channel outlet; 13. Ceramic tube; 14. Shielding sleeve; 15. Terminal block; 2. Dual-channel probe; 21. Shielding shell; 22. Shielding barrel; 23. Scanning collection probe; 24. Reference collection probe; 31. Slide rail; 32. Lead screw; 33. Slider; 34. Stepper motor; 35. Transmission arm; 36. Transmission gear; 4. Outer shell; 51. Lower permanent magnet plate; 52. Upper permanent magnet plate; 6. Side electrode plate; 7. Insulating column; 8. Graphite plate. Detailed Implementation

[0028] 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 some embodiments of the present invention, but not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0029] In the description of the embodiments of the present invention, unless otherwise expressly specified and limited, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance; unless otherwise specified or stated, the term "multiple" refers to two or more; the terms "connected," "fixed," etc., should be interpreted broadly. For example, "connected" can be a fixed connection, a detachable connection, an integral connection, or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in the present invention according to the specific circumstances.

[0030] In this specification, it should be understood that the directional terms such as "upper" and "lower" used in the description of the embodiments of the present invention are used to describe the angles shown in the accompanying drawings and should not be construed as limiting the embodiments of the present invention. Furthermore, in the context, it should also be understood that when it is mentioned that one element is connected "upper" or "lower" to another element, it can be directly connected to the other element "upper" or "lower," or indirectly connected to the other element "upper" or "lower" through an intermediate element.

[0031] As mentioned above, the prior art has the following drawbacks:

[0032] In existing technologies, commonly used methods for measuring ion energy and valence state mainly include the following two types of probes:

[0033] 1. Electrostatic gate energy analyzer (RPA probe)

[0034] RPA (Retarding Potential Analyzer) probes employ a multi-layered metal grid. As ions pass through the probe, a variable electrostatic voltage is applied, progressively blocking ions below a set voltage and allowing only ions above a certain energy threshold to enter the collector. By scanning the voltage and measuring the collection current, the energy distribution function of the ions can be obtained. However, this technique has significant limitations in measuring the plume of micro-electric thrusters:

[0035] (1) The ion current emitted by the ion thruster is extremely weak (usually in the range of milliamperes to tens of milliamperes). After the grid loss, the collection current may be less than 0.1 μA, resulting in an extremely low signal-to-noise ratio.

[0036] (2) The operating voltage of ion thrusters is usually as high as hundreds to thousands of volts. The high voltage creates a strong electric field between the grids, which can easily deflect the ion trajectory, potentially leading to a decrease in energy spectrum resolution or even false signals. In addition, under high voltage, arcs or discharges can easily occur between the grids inside the probe and between the probe and the outer shell, resulting in severe distortion of the measurement signal.

[0037] (3) Measurement relies on step-by-step scanning voltage, making it difficult to quickly obtain the energy distribution of transient ions.

[0038] 2. E×B ion analysis probe

[0039] E×B probes separate ions of different valence states spatially by applying orthogonal electric and magnetic fields within the probe channel, causing ions with different charge-to-mass ratios to be deflected to varying degrees. A slit or porous array is typically placed at the exit point, along with a current collector, to acquire information on the current distribution of ions in different valence states.

[0040] This technology has certain advantages in valence state separation, but it also has obvious shortcomings:

[0041] (1) The energy distributions of ions with different valence states overlap significantly, and the information of high-valence ions is easily overwhelmed by low-valence ions;

[0042] (2) Ions experience significant losses when passing through slits or porous arrays, resulting in a weakening of the collected current signal and increased noise interference;

[0043] (3) This method also relies on voltage scanning to obtain energy distribution, which is difficult to meet the requirements of real-time measurement.

[0044] In summary, existing RPA and E×B probes face technical bottlenecks in the diagnosis of plumes from micro ion thrusters, including low signal-to-noise ratio, insufficient transient response, and difficulty in accurately distinguishing ions of different valence states. Therefore, there is an urgent need to develop a novel measurement device that can achieve high signal-to-noise ratio, real-time response, and separation of multi-valence ions to overcome the limitations of existing technologies.

[0045] To solve the above problems, please refer to Figures 1 to 2 The present invention provides a dual-channel ion energy probe based on magnetic deflection effect, comprising an upper permanent magnet plate 52, a lower permanent magnet plate 51, a dual-channel collimator 1, and a dual-channel probe 2;

[0046] A dual-channel collimator 1 is inserted into the housing 4. The dual-channel collimator 1 includes a scanning channel and a reference channel. The scanning channel and the reference channel are connected to voltages of different values. The dual-channel collimator 1 is used to allow ions to enter the housing 4 along the channel direction. The upper permanent magnet plate 52 and the lower permanent magnet plate 51 are fixed at the upper and lower ends of the housing 4, respectively, to form a uniform magnetic field. The dual-channel probe 2 is disposed in the housing 4 and includes a scanning collection probe 23 that is coplanar with the scanning channel and a reference collection probe 24 that is coplanar with the reference channel. The scanning collection probe 23 and the reference collection probe 24 are connected to voltages of different values.

[0047] A permanent magnet plate assembly is used to create a stable, uniform axial magnetic field, with the magnetic field direction perpendicular to the initial velocity direction of the ion beam. Charged ions entering this magnetic field region are deflected laterally by the Lorentz force. The magnetic field causes ions of different energies to deflect at different angles according to their velocity differences, thereby dispersing them in space according to their energy levels and creating conditions for subsequent energy analysis.

[0048] After magnetic deflection adjustment, the ion beam is split into two parallel channels: a scanning channel and a reference (bias) channel. An ion collection probe is installed at the end of each channel, forming a differential probe array. A slightly different bias voltage is applied to the scanning channel probe and the reference channel probe (e.g., the reference channel voltage is approximately 0.5 V higher than the scanning channel voltage) to form a differential measurement pair. Collector 1 is the scanning channel probe, and collector 2 is the reference channel probe. By comparing the current signals from the two probes, a small differential signal for the corresponding energy range can be obtained, thereby improving measurement resolution and signal-to-noise ratio.

[0049] The ion current signal acquired by the dual-channel probe 2 is first amplified by shielding, then acquired by a high-speed analog-to-digital converter (ADC) and transmitted to the microprocessor unit. The microprocessor calculates the transient ion energy distribution function based on a differential algorithm and suppresses the influence of background noise. Differential processing cancels out the common-mode noise of the two channels, thereby significantly improving the system's sensitivity to weak current signals. The processed energy-current distribution data is output through a communication interface for display or storage devices, and can be used for thruster evaluation or control, etc.

[0050] Specifically, the technical principle and the principle of dual-channel differential measurement:

[0051] This invention utilizes the combined effect of a uniform magnetic field and orthogonal electric fields to separate ions of different energies on a detection plane, thereby obtaining energy distribution information. The motion of charged ions in the combined field satisfies the Lorentz force formula: In the device of this invention, the ion beam first enters a uniform axial magnetic field region. According to the principles of electromagnetism, charged ions experience a Lorentz force in a magnetic field: If we temporarily disregard the influence of the electric field, the ions are only affected by the magnetic field, and its direction is always perpendicular to the velocity vector, causing the ions to undergo circular motion. In this case, the centripetal force provided by the magnetic field satisfies: This formula shows that, for a given magnetic field strength B, the greater the ion velocity v (i.e., the magnitude of its kinetic energy), the larger its orbital radius. The larger the energy, the smaller the orbital radius. Therefore, ions with different energies will produce different degrees of trajectory curvature under the same magnetic field conditions, thus achieving spatial dispersion. The figure below illustrates the trajectory of single-charge Xe⁺ ions with different initial energies (corresponding to accelerating voltages of 200 V to 1800 V) on the detection plane in a uniform axial magnetic field.

[0052] Depend on Figure 2 It is evident that high-energy ions (outside the curve) have a larger deflection radius and a straighter trajectory, while low-energy ions (inside the curve) have a smaller deflection radius and a more pronounced trajectory curvature. This result is consistent with the formula derivation, indicating that a magnetic field can be used to spatially disperse ions of different energies, thereby achieving preliminary energy differentiation.

[0053] Based on the magnetic field, this invention introduces a constant electric field Ey in the y-direction perpendicular to the main motion direction of the ions. At this point, the ions are simultaneously subjected to electric and magnetic forces, with the total force being: Assume the direction of the magnetic field is along... The axis, the initial velocity of the ions mainly along If the axis is defined, then the equation of motion can be decomposed into: , in: This represents the Lorentz force under the influence of a magnetic field, which dominates the circular motion of ions. Represents the electric field force, which directly drives ions in... Directional displacement occurs; when these two factors are superimposed, the trajectory of the ion is no longer a simple circular arc, but rather a composite curve of "cyclotron + lateral translation". Furthermore, it can be seen that the average drift velocity of the ion in the electromagnetic field satisfies the classical E×B drift formula: This velocity is independent of the charge and mass of the ion, and thus introduces the same overall lateral drift for all energy ions.

[0054] In dual-channel differential measurement, it is assumed that the scanning channel and the reference channel receive ion currents of corresponding energy segments as follows: and Because the bias voltages of the two channels have only a slight difference. This leads to a difference in their energy thresholds. Therefore, it can be approximated as .exist When the current is sufficiently small, the difference between the two currents can be expressed as: Therefore, differential signals The difference in current is proportional to the derivative of the energy distribution curve. Using this relationship, the system can convert the probe current difference into differential information of the energy spectrum through digital signal processing, thereby obtaining a high-resolution energy distribution curve. Since the two channels acquire almost the same background noise, differential operations can significantly filter out common-mode noise, improve the signal-to-noise ratio, and enhance the detection capability of weak signals.

[0055] The above technical solution, through the organic combination of magnetic field deflection, dual-channel differential probe and mechanical scanning, realizes high signal-to-noise ratio and high resolution energy distribution measurement of micro ion thruster beam, meeting the stringent requirements of thruster plume diagnosis.

[0056] In some embodiments of the present invention, both channels of the dual-channel collimator 1 are arranged perpendicular to the magnetic field direction, and two side electrode plates 6 are arranged in a direction perpendicular to the dual-channel collimator 1 and the magnetic field direction to form an electric field between the two side electrode plates 6.

[0057] A constant electrostatic field region, powered by a constant-voltage DC power supply, is set up after the magnetic deflection region. The electric field direction is orthogonal (lateral) to the magnetic field direction. This electric field is used to further adjust the ion trajectory after magnetic deflection, achieving ion beam focusing and compensation, enabling it to more accurately reach the probe plane, i.e., the maximum dispersion surface of the ion current obtained through calculation and simulation. The electric field is typically generated by a pair of parallel electrode plates, one connected to a high-voltage constant potential and the other grounded, forming a uniform electrostatic field. Furthermore, the electrode plates and graphite plate 8 are combined for ion current collection and transmission, and the signal is transmitted to the back-end signal acquisition and processing system via a connecting circuit. Combined with differential measurement, the system can record minute changes in ion current with high sensitivity.

[0058] Figure 3 The trajectories of Xe⁺ ions with different energies are shown under the combined action of magnetic and electric fields.

[0059] As shown in the figure, after the electric field is applied, the ion trajectories shift to one side, forming a "teardrop" distribution: high-energy ions have a wider trajectories, while low-energy ions are concentrated and deflected. This effect makes the spatial energy resolution of the ion beam clearer, and the trajectory can be fine-tuned and focused by adjusting the electric field strength.

[0060] Figure 4 The diagram illustrates the dual-channel measurement structure of this invention. Under the influence of an axial magnetic field, the trajectories of ions with different energies undergo differential deflection, thus achieving preliminary energy segmentation and capture. The curves of different colors in the figure represent the projected ion trajectories after magnetic deflection, with the red and green dots corresponding to the receiving positions of the probes in the two channels. Subsequently, dual-channel collimators 1 are set at the front ends of the two channels to limit the incident angle and apply a small potential difference, forming a differential measurement pair. The probe array can move along the y-direction under the drive of a mechanical transmission platform, scanning ions at different deflection angles point by point. Through this design, the system utilizes a magnetic field to achieve energy segmentation, an electric field for fine-tuning focusing, a collimator to ensure beam quality, mechanical scanning to cover the entire spatial position, and dual-channel differential probes to acquire complementary current signals. The synergistic effect of each component effectively filters out common-mode noise, significantly improves the signal-to-noise ratio, and thus rapidly obtains high-resolution, full-range ion energy distribution information.

[0061] Depend on Figure 5 As shown, in some embodiments of the present invention, both the scanning channel and the reference channel include a measurement channel inlet 11, a measurement channel outlet 12, a ceramic tube 13, and a shielding sleeve 14. The measurement channel inlet 11 and the measurement channel outlet 12 are respectively disposed at both ends of the ceramic tube 13, and the shielding sleeve 14 is disposed outside the ceramic tube 13.

[0062] In some embodiments of the present invention, the receiving end of the dual-channel probe 2 is located on the surface of maximum ion current dispersion, and the receiving end faces the outlet direction of the dual-channel collimator 1.

[0063] Please refer to Figure 6 In some embodiments of the present invention, the scanning collection probe 23 and the reference collection probe 24 are connected to a driving device via a transmission arm 35. The driving device is used to drive the scanning collection probe 23 and the reference collection probe 24 to move within the surface of maximum ion current dispersion.

[0064] In some embodiments of the present invention, the driving device includes a stepper motor 34, a transmission gear 36, a slider 33, a lead screw 32, and a slide rail 31. The output end of the stepper motor 34 drives the lead screw 32 through the transmission gear 36. The lead screw 32 and the slide rail 31 pass through the slider 33, and the slider 33 is fixedly connected to the transmission arm 35.

[0065] The detection probe array, consisting of scanning collection probe 23 and reference collection probe 24, is mounted on a movable platform. A stepper motor 34 drives a mechanical transmission mechanism to control the probe position. The mechanical structure includes a transmission arm 35, a slide rail 31, a lead screw 32, and gears, enabling the probes to reciprocate within the area of ​​maximum ion current dispersion. The stepper motor 34 moves the slider 33 and the transmission arm 35, causing the probe array to sweep laterally across a predetermined area, performing point-by-point scanning measurements of the ion beam cross-section. This mechanical scanning method avoids the arcing and grid damage problems that may be caused by high-voltage scanning, improving the system's reliability and safety.

[0066] In some embodiments of the present invention, the scanning collection probe 23 and the reference collection probe 24 share a shielding shell 21. Both the scanning collection probe 23 and the reference collection probe 24 include a shielding barrel 22 and a collection probe mounted on the shielding shell 21. The scanning collection probe 23 and the reference collection probe 24 are respectively disposed in two shielding barrels 22 and do not contact the shielding barrels 22. One end of the shielding barrel 22 is mounted on the shielding shell 21, and the shielding shell 21 is connected to the transmission arm 35.

[0067] In some embodiments of the present invention, the side electrode plate 6 is fixed to the outer casing 4 by an insulating post 7.

[0068] In some embodiments of the present invention, the voltage difference between the scanning channel and the reference channel is 0.5V, and the voltage difference between the scanning collection probe 23 and the reference collection probe 24 is 0.5V.

[0069] The specific workflow of the probe provided in this application is as follows:

[0070] Work process:

[0071] 1. Ion Implantation: The ion beam generated by the DC ion thruster under test is collimated and introduced into the inlet of this test system. A dual-channel collimator is installed at the inlet to limit the ion incident angle and range, ensuring that the ions enter the detection area along the designed trajectory.

[0072] Figure 4 The diagram illustrates a structure where ions entering the detection region are divided into two parallel channels. The upper channel serves as the scanning channel entrance, while the lower channel is the reference channel entrance. Collimators (ceramic tubes 13) are installed within each channel to limit the ion incidence angle and are connected to a high-voltage bias power supply (provided via terminals 15 on the right side of the diagram). Slightly different potentials are applied to the collimators in the scanning and reference channels (the bias channel potential is slightly higher) to ensure that the ion energy ranges entering the two channels are almost identical, but to generate a small current difference during subsequent detection for differential measurement. After entering the magnetic deflection region through these two channels, the ions are deflected according to their energy levels, preparing to enter the next electric field focusing region.

[0073] 2. Magnetic Field Deflection: After entering the stable axially uniform magnetic field region generated by the permanent magnet plate, the ions are deflected laterally by the Lorentz force. According to the principle of magnetic deflection, ions with lower velocity (lower energy) have a smaller deflection radius and a larger deflection angle after being subjected to the magnetic field; ions with higher velocity (higher energy) have a larger deflection radius and a smaller deflection angle. In this way, the originally mixed ions of different energies are spatially dispersed according to their energy levels. High-energy ions are mainly guided to the reference channel side, and low-energy ions are mainly guided to the scanning channel side, achieving preliminary energy segmentation and splitting of the ion beam.

[0074] 3. Electric Field Adjustment: After being deflected by the magnetic field, ions enter an electrostatic field region powered by a constant DC power supply. This electrostatic field is orthogonal to the magnetic field direction, acting to adjust the ion trajectory laterally and longitudinally. The electrostatic field compensates for and focuses the ion trajectory, ensuring the deflected ion beam accurately reaches the probe plane. By adjusting the voltage between the electrodes, ions of different energies can be slightly deflected to optimize the focusing position and eliminate systematic errors caused by channel bias.

[0075] 4. Dual-channel collection and mechanical scanning: After magnetic deflection and electric field modulation, the ion beam is split into two parallel beams in space, which travel along the scanning channel and the reference channel to their respective probe collection regions. A row of ion collection probes is installed at the end of each channel, maintaining a slight difference in bias voltage (typically, the reference channel voltage is slightly higher than the scanning channel voltage, for example, a difference of about 0.5V). The dual-channel probe array 2 is mounted on a mechanical transmission platform, driven by a stepper motor 34 to reciprocate along a plane perpendicular to the ion beam axis, achieving scanning and sampling of the ion beam cross-section. The probe array sequentially scans different spatial positions, collecting ion current signals at corresponding energy levels point by point. This mechanical scanning method covers the entire test area, avoiding arc breakdown and probe damage that may occur with traditional high-voltage electric field scanning, thus improving system reliability.

[0076] 5. Signal Processing: The scanning channel probe and the reference channel probe synchronously acquire the current signals of the ion beam within their respective channels. The two current signals are first amplified by a low-noise amplifier, and then sent to the microprocessor via a high-speed analog-to-digital converter. The processor performs differential operations on the two signals to suppress common-mode noise, thereby improving measurement sensitivity.

[0077] 6. Output Results: The processed data is output as the transient energy distribution curve of the ion current. Due to the use of dual-channel differential measurement, the system directly obtains the energy distribution information in differential form and sends the results to a host computer or display device via a communication interface, providing real-time energy-current distribution data. The measurement results can be used for further applications such as thruster performance evaluation or control optimization.

[0078] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A dual-channel ion energy probe based on magnetic deflection effect, characterized in that, Includes an upper permanent magnet plate, a lower permanent magnet plate, a dual-channel collimator, and a dual-channel probe; The dual-channel collimator extends into the housing and includes a scanning channel and a reference channel. The scanning channel and the reference channel are connected to voltages of different values. The dual-channel collimator is used to allow ions to enter the housing along the channel direction. The upper permanent magnet plate and the lower permanent magnet plate are fixed at the upper and lower ends of the housing, respectively, to form a uniform magnetic field. The dual-channel probe is disposed in the housing and includes a scanning collection probe coplanar with the scanning channel and a reference collection probe coplanar with the reference channel. The scanning collection probe and the reference collection probe are connected to voltages of different values.

2. The ion energy probe according to claim 1, characterized in that, The two channels of the dual-channel collimator are both arranged perpendicular to the direction of the magnetic field, and two side electrode plates are arranged perpendicular to the direction of the dual-channel collimator and the direction of the magnetic field to form an electric field between the two side electrode plates.

3. The ion energy probe according to claim 1, characterized in that, Both the scanning channel and the reference channel include a measurement channel inlet, a measurement channel outlet, a ceramic tube, and a shielding sleeve. The measurement channel inlet and the measurement channel outlet are respectively located at both ends of the ceramic tube, and the shielding sleeve is located outside the ceramic tube.

4. The ion energy probe according to claim 1, characterized in that, The receiving end of the dual-channel probe is located on the surface of maximum ion current dispersion, and the receiving end faces the outlet direction of the dual-channel collimator.

5. The ion energy probe according to claim 1, characterized in that, The scanning collection probe and the reference collection probe are connected to a driving device via a transmission arm. The driving device is used to drive the scanning collection probe and the reference collection probe to move within the surface of maximum ion current dispersion.

6. The ion energy probe according to claim 5, characterized in that, The driving device includes a stepper motor, a transmission gear, a slider, a lead screw, and a slide rail. The output end of the stepper motor drives the lead screw through the transmission gear. The lead screw and the slide rail pass through the slider, and the slider is fixedly connected to the transmission arm.

7. The ion energy probe according to claim 5, characterized in that, The scanning collection probe and the reference collection probe share a shielding shell. Both the scanning collection probe and the reference collection probe include a shielding barrel and a collection probe mounted on the shielding shell. The scanning collection probe and the reference collection probe are respectively disposed in two shielding barrels and do not contact the shielding barrels. One end of the shielding barrel is mounted on the shielding shell, and the shielding shell is connected to the transmission arm.

8. The ion energy probe according to claim 2, characterized in that, The side electrode plate is fixed to the outer casing by insulating posts.

9. The ion energy probe according to claim 1, characterized in that, The voltage difference between the scanning channel and the reference channel is 0.5V, and the voltage difference between the scanning collection probe and the reference collection probe is 0.5V.

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