A method and system for measuring the plasma edge material expansion velocity

Abstract

This invention discloses a method and system for measuring the expansion velocity of plasma edge material, belonging to the field of plasma expansion velocity measurement technology. It solves the technical problem of discontinuous diagnostic time resolution in plasma edge material expansion velocity measurement. The measurement system includes a plasma source, a vacuum pipeline system, a signal detection system, and a data acquisition system. The vacuum pipeline system, signal detection system, and data acquisition system are connected sequentially, forming a high-vacuum sealed environment. The measurement method includes the steps of outputting transmitted X-rays, outputting a pulsed electrical signal from the signal detection system, storing and outputting a digital signal, and extracting the edge material plasma expansion velocity information. This invention is used to measure the expansion velocity of edge material ablation plasma under 100-nanosecond pulse width X-ray pulse irradiation.

Description

Technical Field

[0001] This invention belongs to the field of plasma expansion velocity measurement technology, specifically relating to a method and system for measuring the expansion velocity of plasma edge material. Background Technology

[0002] In high-energy-density plasma physics research, intense pulsed X-rays under high-intensity irradiation conditions, including ultra-intense lasers and Z-pinch radiation, cause rapid ablation of material surfaces, forming plasma and causing it to diffuse. This results in a plasma constriction effect, where pinhole array structures in diagnostic windows or systems become blocked, affecting the subsequent feed of laser light field energy or the diagnostic accuracy of the source strength. Studying the expansion velocity of material at the plasma edge is crucial for correcting the impact of the constriction effect. Furthermore, this method provides an important technical means for studying the characteristics of radiation-ablated plasmas, understanding the inner wall state of radiation transport channels, and exploring the X-ray thermodynamic effects on different materials.

[0003] Existing techniques for measuring the edge material expansion velocity of radiation-ablative plasmas primarily employ diagnostic methods using active X-ray sources to generate backlit probes in conjunction with segmented imaging. These methods are mainly applied in fields such as laser inertial confinement fusion and ultra-intense laser research. Therefore, this technique only addresses nanosecond-level plasma expansion time histories, achieving a limited number of image acquisitions and failing to capture plasma states at continuous time resolution. Furthermore, the constricted aperture target is limited in its specificity. Consequently, the original measurement techniques cannot acquire radiation-ablative plasma velocity information with a wide time-domain continuous resolution of hundreds of nanoseconds and under multiple aperture sizes and intensity adjustments, resulting in a lack of systematic research and understanding.

[0004] In summary, existing measurement techniques for measuring the expansion of material at the edge of radiation-ablative plasma at the nanosecond level face challenges such as discontinuous diagnostic time resolution, the need for active detection X-ray sources, and the requirement for high spatial resolution at the micrometer level. Summary of the Invention

[0005] To overcome the shortcomings of plasma edge material expansion velocity measurement in terms of diagnostic time resolution discontinuity, this invention proposes a method and system for measuring plasma edge material expansion velocity.

[0006] The technical solution adopted by this invention to solve its technical problem is:

[0007] A plasma edge material expansion velocity measurement system includes a plasma source, a vacuum pipeline system, a signal detection system, and a data acquisition system.

[0008] The vacuum pipeline system, signal detection system, and data acquisition system are connected in sequence. The plasma source, vacuum pipeline system, and signal detection system constitute a high-vacuum sealed environment. The signal detection system is used for diagnosing the expansion process of plasma edge material and measuring the expansion rate. The data acquisition system is used for acquiring the expansion rate measurement signal of plasma edge material.

[0009] The plasma source includes a cylindrical filament load, a high-current pulsed power device, a pinhole array target, and a cleaning magnet magnetic attraction sliding adjustment mechanism. The cylindrical filament load, pinhole array target, and cleaning magnet magnetic attraction sliding adjustment mechanism are located within the high-current pulsed power device. The cylindrical filament load is located at the current output center of the high-current pulsed power device, and the central axis of the pinhole array target is aligned with the center of the cylindrical filament load. The cleaning magnet magnetic attraction sliding adjustment mechanism is installed on the vacuum pipe of the vacuum pipe system and is used to adjust the distance between the pinhole array target and the cylindrical filament load. The pinhole array target can move along the axis of the vacuum pipe.

[0010] The vacuum piping system includes a vacuum chamber, vacuum piping, and a vacuum pump unit. The vacuum chamber is fixed to the high-current pulse power device, and the vacuum piping is fixedly connected to the vacuum chamber via an adapter. The vacuum pump unit is fixedly connected to the high-current pulse power device and is used for evacuating the high-current pulse power device, the vacuum chamber, and the vacuum piping.

[0011] The pinhole array target is installed inside a vacuum pipe and is coaxial with the vacuum pipe. The vacuum pipe is matched with the pinhole array target, with one pinhole array target installed in one vacuum pipe. There are two or more vacuum pipes, and the central axis of the vacuum pipe intersects perpendicularly with the central axis of the cylindrical wire array load. The load of the vacuum pipe is evenly distributed relative to the cylindrical wire array.

[0012] One pinhole array target corresponds to one vacuum pipe, one cleaning magnet magnetic attraction sliding adjustment mechanism, one signal detection system, and one data acquisition system. Two or more pinhole array targets are set, with one pinhole array target at a safe distance and the rest at an unsafe distance.

[0013] The aforementioned plasma edge material expansion velocity measurement system includes a pinhole array target comprising a pinhole array filter and a filter clamping disk. The pinhole array filter is a disc, and the filter clamping disk is an annulus. The outer diameter of the pinhole array filter matches the inner diameter of the filter clamping disk, and the filter clamping disk is used to clamp the pinhole array filter.

[0014] The pinhole array filter is provided with periodically arranged pinholes, with a pinhole diameter of 20-50 micrometers and a pinhole spacing of 80-200 micrometers.

[0015] The aforementioned plasma edge material expansion velocity measurement system includes a signal detection system comprising a beam-limiting aperture, a scintillation detection target chamber, a coated modulation scintillator, a quartz glass window, an optical fiber beam transmission, a metal waveguide, a photodetector, an optical attenuator, and an electromagnetic shielding enclosure.

[0016] The beam-limiting aperture and the coated modulation scintillator are installed in the scintillation detection target chamber, and the quartz glass window is installed on the scintillation detection target chamber. The fiber optic beam transmitter, the metal waveguide, the optical attenuator, and the photodetector are connected in sequence.

[0017] The X-rays from the vacuum tube pass sequentially through a beam-limiting aperture and a coated modulation scintillator. Visible light is emitted from the coated modulation scintillator and passes sequentially through a quartz glass window, an optical fiber beam guide, a metal waveguide, and an optical attenuator before entering a photodetector.

[0018] The metal waveguide passes through the electromagnetic shielding enclosure, and the photodetector and optical attenuator are located inside the electromagnetic shielding enclosure.

[0019] The scintillation detection target chamber is connected to the vacuum pipeline in a vacuum seal.

[0020] In the aforementioned plasma edge material expansion velocity measurement system, the coated modulation scintillator is a plastic scintillator with a copper film coating on its surface, which has a flattening sensitivity response in the soft X-ray energy band.

[0021] The aforementioned plasma edge material expansion velocity measurement system includes a data acquisition system comprising a data acquisition instrument, a signal receiver, a storage module, a photoelectric conversion module, an electro-optical conversion module, a high-voltage source, an uninterruptible power supply, and a digital signal delay generator.

[0022] The high-voltage source supplies high-voltage power to the photodetector via a high-voltage cable. The uninterruptible power supply supplies power to the high-voltage source, photoelectric conversion module, and data acquisition instrument via a power supply line.

[0023] The photodetector outputs an analog signal to a data acquisition unit, which converts the received analog signal into a digital signal and transmits it to a signal receiver via a bundled optical fiber. The signal receiver receives the digital signal from the data acquisition unit and transmits it to a storage module via a network cable. The storage module stores the digital signal.

[0024] The digital signal delay generator receives instructions from the high-current pulse power device and sends an electrical pulse signal to the electro-optical conversion module. The electro-optical conversion module converts the received electrical pulse signal into an optical signal. The optical signal is transmitted to the photoelectric conversion module through a trigger transmission optical fiber. The electrical signal output by the photoelectric conversion module is transmitted to the data acquisition instrument through a trigger cable, triggering the data acquisition instrument to start acquiring the analog signal of the photodetector.

[0025] The data acquisition instrument, photoelectric conversion module, high-voltage source, and uninterruptible power supply are located inside the electromagnetic shielding enclosure. The trigger transmission fiber and the bundled signal fiber pass through the electromagnetic shielding enclosure.

[0026] The aforementioned plasma edge material expansion velocity measurement system includes four pinhole array targets, corresponding to one standard measurement group and three control measurement groups.

[0027] The threshold distance is 1 meter.

[0028] In the three control measurement groups, the distance from the pinhole array target to the cylindrical wire array load ranged from 4cm to 10cm and was not equal.

[0029] The vacuum pipe is made of 316L stainless steel with magnetic permeability.

[0030] The photodetector is a photomultiplier tube.

[0031] The scintillation detection target chamber has a Y-shaped structure and is connected to the end of the vacuum pipe. The inner wall is blackened. The mounting plane of the coated modulation scintillator is at a 45-degree angle to the optical axis and perpendicular to the normal of the optical fiber beam receiving plane.

[0032] The electromagnetic shielding enclosure is fully welded for moisture protection, with inner and outer layers of insulation. The inner layer is floating, and the outer layer is grounded. The inner enclosure is independently powered by an uninterruptible power supply. The shielding enclosure door is tightly closed by metal springs, and the gaps in the band tubes are sealed with metal wool.

[0033] A method for measuring the expansion velocity of plasma edge material includes the following steps:

[0034] Step 1, output transmitted X-rays

[0035] The pinhole array targets of the standard measurement group and the control measurement group are placed in their respective vacuum pipes, and the distance from the pinhole array target to the cylindrical wire array load is set.

[0036] The cylindrical wire array load generates radiation, and the high-current pulse power device sends a command to the data acquisition system, which then starts working.

[0037] The vacuum pipes of the standard measurement group and the control measurement group output standard transmission X-rays and control transmission X-rays, respectively.

[0038] Step 2: The signal detection system outputs a pulse electrical signal.

[0039] Standard X-rays and control X-rays enter their respective signal detection systems, and the signal detection systems of the standard measurement group and the control measurement group output standard pulse electrical signals and control pulse electrical signals, respectively.

[0040] Step 3: Store and output digital signals

[0041] The standard pulse electrical signal and the control pulse electrical signal are respectively entered into their respective data acquisition systems. The data acquisition systems of the standard measurement group and the control measurement group convert the pulse electrical signals into standard group digital signals and control group digital signals, respectively, store them, and output them.

[0042] Step 4: Extract the plasma expansion velocity information of edge matter.

[0043] The data acquisition system calculates the curve of plasma edge material expansion velocity versus time based on the standard group digital signal, the control group digital signal, the pinhole diameter, and the pinhole spacing.

[0044] In the above-mentioned method for measuring the expansion velocity of plasma edge material, the control measurement group consists of 3 sets, and the distance from the pinhole array target to the cylindrical wire array load in each set is not equal.

[0045] The beneficial effects of this invention are:

[0046] A method for measuring the expansion velocity of plasma edge material is disclosed. X-rays radiated from the source region pass through a pinhole region where the effective area shrinks due to the expansion of the edge plasma. The X-rays are then emitted and irradiated onto a scintillator via an aperture, converting into a visible light signal. This visible light signal is then transmitted through a beam into an electromagnetically shielded box, collected by a photodetector, and converted into an electrical signal. This signal is then acquired by a data acquisition instrument and transmitted via optical fiber to a storage module for storage. This technical solution solves the problem in existing measurement systems that, when measuring the expansion velocity of edge ablation plasma under 100-nanosecond pulse X-ray irradiation, cannot obtain wide-domain continuous-time resolution and require active-detection X-ray sources and high-spatial-resolution system designs.

[0047] A plasma edge material expansion velocity measurement system, compared with existing measurement systems, adopts a coaxial symmetrical layout structure to realize signal comparison analysis, which enhances the reliability of the measurement signal; it adopts direct measurement and comparison of the total radiation power of soft X-rays across the entire energy range, which enhances the strength of the received signal; and it adopts a current-type photodetector to achieve continuous time resolution in a wide time domain.

[0048] A plasma edge material expansion velocity measurement system employs a scintillation detection method using a scintillator with a beam transmission and matched with photodetectors of different sensitivities. This improves the sensitivity of X-ray radiation power detection, enhances the ability to distinguish low-intensity weak signals, and broadens the linear dynamic range of the detection system.

[0049] A plasma edge material expansion velocity measurement system employs a pinhole array target to generate radiation ablation of the plasma edge material expansion process. Compared to the original method using a single pinhole, the pinhole array structure, by controlling the pinhole diameter and arrangement period, can effectively adjust the amplitude of the contrast signal under the same plasma edge material expansion velocity. Furthermore, it can be further differentiated according to different material properties and source region radiation characteristics to optimize the extraction of characteristic parameters of plasma expansion velocity.

[0050] A plasma edge material expansion velocity measurement system employs a scintillation detection system with a coated modulated scintillator, which has the advantages of high detection sensitivity and flattened energy spectrum response, and can realize the direct measurement of the total radiation power of soft X-rays across the entire energy range. Attached Figure Description

[0051] Figure 1 This is a schematic diagram of the pinhole array target structure according to Embodiment 1 of the present invention;

[0052] Figure 2 This is a schematic diagram of the pinhole arrangement of a pinhole array target according to Embodiment 1 of the present invention;

[0053] Figure 3 This is a schematic diagram of the plasma radiation source and vacuum pipeline system according to Embodiment 1 of the present invention;

[0054] Figure 4 This is a schematic diagram of the signal detection system and data acquisition system according to Embodiment 1 of the present invention.

[0055] The attached figures are labeled as follows:

[0056] 101-Filter plate clamping plate, 102-Pinhole array filter plate, 103-Pinhole diameter, 104-Pinhole spacing;

[0057] 8-Plasma source, 1-Cylindrical filament array load, 2-High current pulse power device, 4-Pinhole array target, 6-Cleaning magnet magnetic attraction sliding adjustment mechanism;

[0058] 9-Vacuum piping system, 3-Vacuum chamber, 5-Vacuum piping, 7-Vacuum pump set;

[0059] 10-Signal detection system, 14-Beam limiting aperture, 15-Scintillator detection target chamber, 16-Coated modulation scintillator, 17-Quartz glass window, 18-Fiber optic beam transmission, 19-Beam transmission splitter, 20-Metal waveguide, 21-Photodetector, 22-High voltage cable, 23-Signal cable, 24-Trigger cable, 25-Photoelectric conversion module, 26-Trigger transmission fiber, 31-Optical attenuator, 34-Electromagnetic shielding box;

[0060] 11-Data acquisition system, 27-Data acquisition instrument, 28-High voltage source, 29-Uninterruptible power supply, 30-Power supply line, 32-Built signal fiber optic cable, 35-Signal receiver, 36-Storage module, 37-Network cable, 40-Digital signal delay generator, 41-Electro-optical conversion module;

[0061] 50 - Standard measurement group, 51 - Control measurement group. Detailed Implementation

[0062] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0063] Example 1

[0064] like Figure 3 and Figure 4 As shown, a measurement system for the expansion velocity of matter at the edge of a plasma mainly comprises four subsystems: a plasma source 8, a vacuum system 9, a signal detection system 10, and a data acquisition system 11. The plasma radiation source 8 is connected to the signal detection system 10 via a vacuum pipeline system, forming a high-vacuum sealed environment. The data acquisition system 11 is connected to the signal detection system 10 via a photodetector to achieve signal acquisition and storage.

[0065] The plasma source 8 includes a cylindrical filament array load 1, a high-current pulsed power device 2, and a pinhole array target 4;

[0066] Vacuum system 9 includes vacuum chamber 3, vacuum pipe 5, and vacuum pump set 7;

[0067] The signal detection system 10 includes a beam-limiting aperture 14, a scintillation detection target chamber 15, a coated modulation scintillator 16, a quartz glass window 17, an optical fiber beam transmission 18, a metal waveguide, a photomultiplier detector 21, an optical attenuator 31, and an electromagnetic shielding box 34.

[0068] The data acquisition system 11 mainly includes a data acquisition instrument 27, a signal receiver 35, a storage module 36, a photoelectric conversion module 24, an electro-optical conversion module 41, a trigger transmission fiber 26, a signal bundle fiber 32, a high voltage source 28, an uninterruptible power supply 29, and a digital signal delay generator 40.

[0069] The X-ray radiation source is located at the front end and is generated by a cylindrical wire array load 1 driven by a high-current pulsed power device 2, exhibiting 360-degree axisymmetric radiation output. The X-ray radiation source radiates onto the surface of the pinhole array target 4, producing a radiation ablation effect and forming a plasma source.

[0070] The pinhole array target 4 is coaxially aligned and installed inside the vacuum pipe 5. The pinhole array target of the standard signal control group 50 is located in the middle section of the vacuum pipe, and the pinhole array target of the plasma expansion velocity measurement control group 51 is located at the front end of the vacuum pipe. The end of the vacuum pipe is connected to the interface of the scintillation detection target chamber 15.

[0071] The scintillation detection target chamber 15 is coaxially and centeredly connected to the vacuum pipe 5. The scintillator is set at a 45-degree angle to the optical path to convert the X-ray signal into a visible light signal, which then enters the target chamber branch pipe.

[0072] A quartz glass window 17 is installed at the end of the target chamber branch pipe to achieve vacuum sealing and to be tightly connected to the quartz fiber optic transmission beam 18. The visible light signal is collected and transmitted by the fiber optic transmission beam 18 after passing through the quartz glass window 17, and then the light signal is divided equally by the transmission beam splitter 19. After passing through the waveguide 20, it is introduced into the inner box of the double-layer shielded box and connected to the photodetector 21.

[0073] The photodetector 21 performs photoelectric conversion and signal multiplication. The output electrical signal is transmitted to the data acquisition instrument 27 through the signal cable 22 and digitized. The digitized signal is bundled into the main optical fiber 32 through each fiber core and transmitted to the signal receiver 35 for reception and recording. The data is then stored by the storage module 36.

[0074] The high-voltage source 28 provides high-voltage input to all photodetectors 21 inside the enclosure via high-voltage cable 23.

[0075] The double-layer electromagnetic shielding enclosure 34 adopts a double-layer fully welded moisture-proof electromagnetic shielding design. The inner and outer layers are separated by insulating marble material to achieve insulation support. The inner enclosure is floating on the ground to isolate external interference, while the outer enclosure is connected to the ground with low resistance.

[0076] The digital signal delay generator 40 receives an external trigger signal from the device, and after a specific delay, distributes a synchronous output signal to trigger the electro-optical conversion module 41. The signal is then transmitted through the trigger transmission fiber 26 to the inside of the double-layer shielded box 34, where it is connected to the photoelectric conversion module 25. The optical signal is converted into an electrical signal and input to the trigger terminal of the data acquisition instrument 27 to achieve synchronous triggering.

[0077] like Figure 1 , 2 As shown, a pinhole array target is used as a radiation ablation plasma source in a system for measuring the expansion velocity of matter at the plasma edge. The modulation of the pinhole array structure and the target material directly affects the characteristics of the contrast signal. Therefore, by adjusting and optimizing, the pinhole velocity signal at a series of different orders of magnitude can be enhanced, achieving velocity discrimination at the 0.01 micrometer per nanosecond level.

[0078] Example 2

[0079] A system for measuring the expansion velocity of matter at the edge of plasma comprises a cylindrical wire array load mounted at the center of the anode and cathode load mounting area of ​​a high-current device, simultaneously located at the front end of a vacuum pipe. The vacuum pipe is divided into four coaxially symmetrically arranged sections, with its axis perpendicular to and aligned with the axis of the cylindrical wire array load. A pinhole array target support frame is installed inside the vacuum pipe, upon which the pinhole array target is coaxially mounted. The vacuum pipe is made of 316L stainless steel with magnetic permeability. Cleaning magnets and movable sliding structures can be installed on the outside of the pipe at the corresponding positions of the pinhole array targets. By adjusting the position of the magnets and simultaneously magnetically attracting the pinhole array target support frame, the distance between the pinhole array target and the plasma radiation source can be adjusted, ultimately changing the irradiation intensity of the pinhole array target while also serving as a cleaning function for stray electrons within the pipe. A scintillation detection target chamber is connected to the end of the vacuum pipe, and the end of the scintillation detection target chamber is vacuum-sealed using a quartz glass window.

[0080] The pinhole array target is used to form an ablation plasma edge material expansion region under irradiation; the pinhole array target consists of a pinhole array filter and a filter clamping disk; the pinhole array filter has a periodically arranged pinhole structure; the pinhole diameter is 20~50 micrometers, and the pinhole arrangement period is 80~200 micrometers.

[0081] The high-current pulsed power device and cylindrical wire array load generate an axisymmetric pulsed X-ray radiation source, realizing the integration of radiation source and diagnostic source, and integrating the formation of edge material expansion process of radiation ablation plasma and the formation of diagnostic detection light.

[0082] Furthermore, the vacuum pipes are divided into four groups, each connected to one of the four diagnostic windows of the high-current pulse power device, and are evenly distributed in a 360-degree azimuth. One group is set as the standard group, in which the pinhole array targets inside the vacuum pipe are located in a safe area 1m away from the radiation source, where no radiation ablation plasma is generated, serving as a standard control; the other three groups are set as the experimental group, in which the pinhole array targets inside the vacuum pipe are arranged in a tiered manner in a close-range area within 4-10cm of the radiation source, forming a control for testing the expansion rate of matter at the plasma edge.

[0083] Furthermore, the ends of the vacuum pipes are all connected to scintillation detection target chambers to achieve soft X-ray radiation power diagnosis.

[0084] The beam transmission uses a split-beam quartz fiber bundle. The main end of the fiber bundle is connected to the quartz window of the scintillation detection target chamber, and the other end of the split fiber bundle enters the inner chamber through a double-layer shielded waveguide and connects to the photodetector.

[0085] The photodetector is a photomultiplier tube.

[0086] The scintillation detection target chamber has a Y-shaped structure and is connected to the end of the vacuum pipe. The inner wall is blackened. The scintillator support extends in from the opposite side for installation. The scintillator mounting plane is at a 45-degree angle to the optical axis and perpendicular to the normal of the beam receiving plane.

[0087] The coated modulation scintillator is a plastic scintillator with a copper film coating on its surface, which has a flattened sensitivity response at different energy points in the soft X-ray energy range.

[0088] Furthermore, the beam-limiting aperture is located at the front end of the coated modulation scintillator.

[0089] Furthermore, the data acquisition and storage system includes a high-frequency sampling data acquisition instrument, a signal receiver, and a signal storage module.

[0090] Furthermore, the electromagnetic shielding enclosure is fully welded for moisture protection, with inner and outer layers insulated and isolated, the inner layer floating and the outer layer grounded. The inner enclosure is independently powered by an uninterruptible power supply. The shielding enclosure door is tightly closed by metal springs, and all gaps in the band tubes are tightly sealed with metal wool.

[0091] A method for measuring the expansion velocity of matter at the plasma edge includes the following steps:

[0092] Step 1, detect the output signal of the system

[0093] Build a system for measuring the expansion velocity of matter at the plasma edge;

[0094] A high-current pulsed power device and a cylindrical wire array load are used to generate an axisymmetric X-ray radiation source, producing a high-pulse X-ray radiation process on the order of hundreds of nanoseconds. The X-rays irradiate the pinhole array target, ablating and forming a plasma source. This creates an expansion and diffusion region of material at the plasma edge. Simultaneously, the X-rays pass through the pinholes of the irradiated target and are collected and diagnosed by the detection system. A synchronization signal is distributed via a digital signal delay generator. The synchronization output signal is sequentially transmitted through an electro-optical conversion module, a trigger transmission fiber, and a photoelectric conversion module to the trigger terminal of the data acquisition instrument, triggering the data acquisition unit to record the output signal of the detection system.

[0095] Furthermore, step 1) specifically involves:

[0096] X-rays pass through arrayed pinholes on the target. Within the region where the plasma expands and enters the pinhole area, the X-rays are blocked; outside the region where the plasma does not enter the pinhole area, the X-rays pass through completely. The X-ray transmission ratio changes as the plasma expansion region expands.

[0097] Step 2: The photodetector collects the light signal.

[0098] X-rays from the source region pass through the target and the beam-limiting aperture, then strike the coated modulated scintillator, converting it into a visible light signal. This visible light signal is coupled through a quartz glass window into the fiber optic beam. After uniform beam splitting, the beam is transmitted to the detection interfaces of photodetectors within a double-layered electromagnetically shielded enclosure, where the photodetectors collect the signal.

[0099] Step 3: Convert the optical signal into an electrical signal.

[0100] The photodetector receives optical signals and converts them into electrical signals;

[0101] Step 4: The storage module stores the digital signal.

[0102] The electrical signal is transmitted to the data acquisition instrument via the signal cable and then acquired as a digital signal. The digital signal is then transmitted to the signal receiver via the bundled signal optical fiber and stored by the storage module.

[0103] Step 5: Extract the plasma expansion velocity information of edge matter.

[0104] The pinhole array target in the standard group was placed at the far end of the vacuum pipe, resulting in no ablation plasma formation; otherwise, it was consistent with the control group. Information on the plasma expansion velocity of the edge material was extracted by comparing the signals from the standard group and the control group.

[0105] Furthermore, in step 5), the pinhole target location in the standard group is a low-irradiation-intensity region at the far end, where no edge-material ablation plasma is formed. First, the control group conditions must be set to be the same as the standard group. Only after the waveforms of the control group and the standard group show high consistency, completing the consistency comparison of the detection system, can the next step be carried out; otherwise, adjust the system and detector selection until the consistency requirements are met.

[0106] Furthermore, the position of the pinhole array target in the control group was moved to within 10 cm of the plasma radiation source using a magnetic sliding adjustment mechanism with a cleaning magnet. This ensured that the pinhole array target in the control group underwent radiation ablation and expansion of the plasma edge material during irradiation. The experimental waveforms of the standard group and the control group were recorded simultaneously, and the waveforms A measured in the standard group and B measured in the control group were time-aligned with an alignment accuracy better than 1 ns.

[0107] Further, the difference between the aligned waveforms is taken to obtain waveform C; this is then compared with the standard waveform A to obtain waveform D. This signal characterizes the proportion of signal blocked by the expanding plasma; the radius r of the region where the plasma did not expand into the pinhole region is calculated using D to obtain waveform E; the slope curve of waveform E is calculated to obtain waveform F, which ultimately characterizes the curve of the edge expansion velocity of the radiation ablation plasma as a function of time.

[0108] Example 3

[0109] A plasma edge matter expansion velocity measurement system includes a plasma source 8, a vacuum pipeline system 9, a signal detection system 10, and a data acquisition system 11.

[0110] Plasma source 8, vacuum pipeline system 9, signal detection system 10, and data acquisition system 11 are connected in sequence. Plasma source 8, vacuum pipeline system 9, and signal detection system 10 constitute a high vacuum sealed environment. Data acquisition system 11 and signal detection system 10 are used for signal acquisition and storage.

[0111] The plasma source 8 includes a cylindrical filament array load 1, a high-current pulse power device 2, a pinhole array target 4, and a cleaning magnet magnetic attraction sliding adjustment mechanism 6.

[0112] The cylindrical wire array load 1, the pinhole array target 4, and the cleaning magnet magnetic attraction sliding adjustment mechanism 6 are located inside the high current pulse power device 2.

[0113] The cylindrical wire array load 1 is located at the current output center of the high current pulse power device 2. The central axis of the pinhole array target 4 is directly opposite the center of the cylindrical wire array load 1. The cleaning magnet magnetic attraction sliding adjustment mechanism 6 is installed on the vacuum pipe 5 of the vacuum pipe system 9 and is used to adjust the position of the pinhole array target 4. The pinhole array target 4 moves along the axis of the vacuum pipe 5.

[0114] The pinhole array target 4 consists of two or more pinholes.

[0115] The pinhole array target 4 includes a pinhole array filter 102 and a filter clamping disk 101. The pinhole array filter 102 is a disk, and the filter clamping disk 101 is an annulus. The outer diameter of the pinhole array filter 102 matches the inner diameter of the filter clamping disk 101, and the filter clamping disk 101 is used to clamp the pinhole array filter 102.

[0116] The pinhole array filter 102 is provided with periodically arranged pinholes, with a pinhole diameter of 20~50 micrometers and a pinhole spacing of 80~200 micrometers.

[0117] The vacuum piping system 9 includes a vacuum chamber 3, a vacuum pipe 5, and a vacuum pump unit 7.

[0118] Vacuum chamber 3 is fixed to high-current pulse power device 2, and vacuum pipe 5 is fixedly connected to vacuum chamber 3 via an adapter. Vacuum pump unit 7 is fixedly connected to high-current pulse power device 2 and is used to evacuate high-current pulse power device 2, vacuum chamber 3, and vacuum pipe 5.

[0119] The pinhole array target 4 is installed inside the vacuum pipe 5 and is coaxial with the vacuum pipe 5.

[0120] One pinhole array target 4 is installed inside a vacuum pipe 5.

[0121] The signal detection system 10 includes a beam-limiting aperture 14, a scintillation detection target chamber 15, a coated modulation scintillator 16, a quartz glass window 17, an optical fiber beam transmission beam 18, a metal waveguide 20, a photodetector 21, an optical attenuator 31, and an electromagnetic shielding box 34.

[0122] A beam-limiting aperture 14 and a coated modulation scintillator 16 are installed inside the scintillation detection target chamber 15, and a quartz glass window 17 is installed on the scintillation detection target chamber 15.

[0123] The fiber optic beam 18, the metal waveguide 20, the optical attenuator 31, and the photodetector 21 are connected in sequence.

[0124] The X-rays from the vacuum tube 5 pass sequentially through the beam-limiting aperture 14 and the coated modulation scintillator 16. The coated modulation scintillator 16 emits visible light, which passes sequentially through the quartz glass window 17, the fiber optic beam 18, the metal waveguide 20, and the optical attenuator 31 before entering the photodetector 21.

[0125] The scintillation detection target chamber 15 is vacuum-sealed to the vacuum pipe 5.

[0126] The metal waveguide 20 passes through the electromagnetic shielding box 34, and the photodetector 21 and the optical attenuator 31 are located inside the electromagnetic shielding box 34.

[0127] The coated modulation scintillator 16 is a plastic scintillator with a copper film coating on its surface, which has a flattening sensitivity response in the soft X-ray energy range.

[0128] The data acquisition system 11 includes a data acquisition instrument 27, a signal receiver 35, a storage module 36, a photoelectric conversion module 25, a high-voltage source 28, an uninterruptible power supply 29, a digital signal delay generator 40, and an electro-optical conversion module 41.

[0129] The signal output by photodetector 21 is sent to data acquisition instrument 27. High-voltage source 28 supplies high-voltage power to photodetector 21 through high-voltage cable 22. Uninterruptible power supply 29 supplies power to high-voltage source 28, photoelectric conversion module 25, and data acquisition instrument 27 through power supply line 30.

[0130] The analog signal output by the photodetector 21 is sent to the data acquisition unit 27. The data acquisition unit 27 converts the received analog signal into a digital signal and transmits it to the signal receiver 35 via the bundled signal fiber optic cable 32. The signal receiver 35 receives the digital signal from the data acquisition unit 27 and transmits it to the storage module 36 via the network cable 37. The storage module 36 stores the digital signal.

[0131] The digital signal delay generator 40 receives the instruction from the high current pulse power device 2 and sends an electrical pulse signal to the electro-optical conversion module 41. The electro-optical conversion module 41 converts the received electrical pulse signal into an optical signal. The optical signal is transmitted to the photoelectric conversion module 25 through the trigger transmission optical fiber 26. The electrical signal output by the photoelectric conversion module 25 is transmitted to the data acquisition instrument 27 through the trigger cable 24, triggering the data acquisition instrument 27 to start acquiring the analog signal of the photodetector 21.

[0132] The data acquisition instrument 27, photoelectric conversion module 25, high-voltage source 28, and uninterruptible power supply 29 are located inside the electromagnetic shielding enclosure 34. The trigger transmission fiber 26 and the bundled signal fiber 32 pass through the electromagnetic shielding enclosure 34.

[0133] When the distance between the pinhole array target 4 and the cylindrical wire array load 1 is greater than the threshold distance, the pinhole array target 4 is at a safe distance and does not produce radiation ablation, i.e., it does not generate plasma. When the distance between the pinhole array target 4 and the cylindrical wire array load 1 is less than or equal to the threshold distance, the pinhole array target 4 is at an unsafe distance and produces radiation ablation, i.e., it generates plasma.

[0134] One pinhole array target 4 corresponds to one vacuum pipe, one cleaning magnet magnetic attraction sliding adjustment mechanism, one signal detection system, and one data acquisition system, forming one measurement group. When the pinhole array target 4 is at a safe distance, the measurement group is the standard measurement group; when the pinhole array target 4 is at an unsafe distance, the measurement group is the control measurement group.

[0135] Two or more pinhole array targets 4 are set, of which one pinhole array target 4 is at a safe distance, and the rest of the pinhole array targets 4 are at an unsafe distance.

[0136] The threshold distance is 1 meter.

[0137] Preferably, four pinhole array targets 4 are provided, corresponding to one standard measurement group and three control measurement groups. In the three control measurement groups, the distance from the pinhole array target 4 to the cylindrical wire array load 1 is 4~10cm.

[0138] In several sets of control measurement groups, the distances from the pinhole array target 4 to the cylindrical wire array load 1 were not equal.

[0139] A method for measuring the expansion velocity of plasma edge matter, using a plasma edge matter expansion velocity measurement system, includes the following steps:

[0140] Step 1, output transmitted X-rays

[0141] The pinhole array targets 4 of the standard measurement group and the control measurement group are placed in their respective vacuum pipes 5, and the distance from the pinhole array target 4 to the cylindrical wire array load 1 is set.

[0142] The cylindrical wire array load 1 generates radiation, and the high-current pulse power device 2 sends a command to the data acquisition system 11, which then starts working.

[0143] The vacuum pipes 5 of the standard measurement group and the control measurement group output standard transmission X-rays and control transmission X-rays, respectively.

[0144] Step 2: The signal detection system outputs a pulse electrical signal.

[0145] Standard X-rays and control X-rays enter their respective signal detection systems 10, and the signal detection systems 10 of the standard measurement group and the control measurement group output standard pulse electrical signals and control pulse electrical signals, respectively.

[0146] Step 3: Store and output digital signals

[0147] The standard pulse electrical signal and the control pulse electrical signal are respectively entered into their respective data acquisition systems 11. The data acquisition systems 11 of the standard measurement group and the control measurement group convert the pulse electrical signals into standard group digital signals and control group digital signals, respectively, store them and output them.

[0148] Step 4: Extract the plasma expansion velocity information of edge matter.

[0149] The data acquisition system 11 calculates the curve of the expansion velocity of plasma edge material over time based on the digital signals of the standard group, the digital signals of the control group, the pinhole diameter, and the pinhole spacing.

Claims

1. A system for measuring the expansion velocity of matter at the edge of a plasma, characterized in that, Includes a plasma source (8), a vacuum pipeline system (9), a signal detection system (10), and a data acquisition system (11). The vacuum pipeline system (9), signal detection system (10), and data acquisition system (11) are connected in sequence. The plasma source (8), vacuum pipeline system (9), and signal detection system (10) constitute a high vacuum sealed environment. The signal detection system (10) is used for diagnosis of the plasma edge material expansion process and measurement of expansion rate. The data acquisition system (11) is used for acquisition and storage of plasma edge material expansion rate measurement signals. The plasma source (8) includes a cylindrical wire array load (1), a high-current pulse power device (2), a pinhole array target (4), and a cleaning magnet magnetic attraction sliding adjustment mechanism (6); the cylindrical wire array load (1), the pinhole array target (4), and the cleaning magnet magnetic attraction sliding adjustment mechanism (6) are located inside the high-current pulse power device (2); the cylindrical wire array load (1) is located at the current output center of the high-current pulse power device (2), the central axis of the pinhole array target (4) is directly opposite the center of the cylindrical wire array load (1), and the cleaning magnet magnetic attraction sliding adjustment mechanism (6) is installed on the vacuum pipe (5) of the vacuum pipe system (9) to adjust the distance between the pinhole array target (4) and the cylindrical wire array load (1), and the pinhole array target (4) can move along the axis of the vacuum pipe (5); The vacuum pipeline system (9) includes a vacuum chamber (3), a vacuum pipeline (5), and a vacuum pump group (7); the vacuum chamber (3) is fixed on the high current pulse power device (2), and the vacuum pipeline (5) is fixedly connected to the vacuum chamber (3) through an adapter; the vacuum pump group (7) is fixedly connected to the high current pulse power device (2) and is used to evacuate the high current pulse power device (2), the vacuum chamber (3), and the vacuum pipeline (5); The pinhole array target (4) is installed inside the vacuum pipe (5) and is coaxial with the vacuum pipe (5); the vacuum pipe (5) is matched with the pinhole array target (4), and one pinhole array target (4) is installed in one vacuum pipe (5); there are two or more vacuum pipes (5), and the central axis of the vacuum pipe (5) intersects perpendicularly with the central axis of the cylindrical wire array load (1), and the vacuum pipe (5) is evenly distributed relative to the cylindrical wire array load (1); One pinhole array target (4) corresponds to one vacuum pipe, one cleaning magnet magnetic attraction sliding adjustment mechanism, one signal detection system, and one data acquisition system; two or more pinhole array targets (4) are set, of which one pinhole array target (4) is at a safe distance, and the other pinhole array targets (4) are at an unsafe distance.

2. The plasma edge matter expansion velocity measurement system according to claim 1, characterized in that, The pinhole array target (4) includes a pinhole array filter (102) and a filter clamping disk (101); the pinhole array filter (102) is a disk, the filter clamping disk (101) is an annulus, the outer diameter of the pinhole array filter (102) matches the inner diameter of the filter clamping disk (101), and the filter clamping disk (101) is used to clamp the pinhole array filter (102). The pinhole array filter (102) is provided with periodically arranged pinholes, with a pinhole diameter of 20 micrometers to 50 micrometers and a pinhole spacing of 80 micrometers to 200 micrometers.

3. The plasma edge matter expansion velocity measurement system according to claim 1, characterized in that, The signal detection system (10) includes a beam-limiting aperture (14), a scintillation detection target chamber (15), a coated modulation scintillator (16), a quartz glass window (17), an optical fiber beam transmission (18), a metal waveguide (20), a photodetector (21), an optical attenuator (31), and an electromagnetic shielding box (34). The beam-limiting aperture (14) and the coated modulation scintillator (16) are installed inside the scintillation detection target chamber (15), and the quartz glass window (17) is installed on the scintillation detection target chamber (15); the fiber optic beam (18), the metal waveguide (20), the optical attenuator (31), and the photodetector (21) are connected in sequence. The X-rays from the vacuum tube (5) pass through the beam-limiting aperture (14) and the coated modulation scintillator (16) in sequence; the coated modulation scintillator (16) emits visible light, which passes through the quartz glass window (17), the fiber beam (18), the metal waveguide (20), and the optical attenuator (31) in sequence, and enters the photodetector (21). The metal waveguide (20) passes through the electromagnetic shielding box (34), and the photodetector (21) and the optical attenuator (31) are located inside the electromagnetic shielding box (34); The scintillation detection target chamber (15) is vacuum-sealed to the vacuum pipe (5).

4. The plasma edge matter expansion velocity measurement system according to claim 3, characterized in that, The film-modulated scintillator (16) is a plastic scintillator with a copper film coating on its surface, which has a flattening sensitivity response in the soft X-ray energy band.

5. The plasma edge matter expansion velocity measurement system according to claim 1, characterized in that, The data acquisition system (11) includes a data acquisition instrument (27), a signal receiver (35), a storage module (36), a photoelectric conversion module (25), an electro-optical conversion module (41), a high voltage source (28), an uninterruptible power supply (29), and a digital signal delay generator (40). The high-voltage source (28) supplies high-voltage power to the photodetector (21) through the high-voltage cable (22); the uninterruptible power supply (29) supplies power to the high-voltage source (28), the photoelectric conversion module (25), and the data acquisition instrument (27) through the power supply line (30); The analog signal output by the photodetector (21) is sent to the data acquisition instrument (27). The data acquisition instrument (27) converts the received analog signal into a digital signal and transmits it to the signal receiver (35) through the bundled signal fiber (32). The signal receiver (35) receives the digital signal from the data acquisition instrument (27) and transmits it to the storage module (36) through the network cable (37). The storage module (36) stores the digital signal. The digital signal delay generator (40) receives the instruction from the high current pulse power device (2) and sends an electrical pulse signal to the electro-optical conversion module (41). The electro-optical conversion module (41) converts the received electrical pulse signal into an optical signal. The optical signal is transmitted to the photoelectric conversion module (25) through the trigger transmission fiber (26). The electrical signal output by the photoelectric conversion module (25) is transmitted to the data acquisition instrument (27) through the trigger cable (24). The trigger data acquisition instrument (27) starts to acquire the analog signal of the photodetector (21). The data acquisition instrument (27), photoelectric conversion module (25), high voltage source (28), and uninterruptible power supply (29) are located inside the electromagnetic shielding box (34); the trigger transmission fiber (26) and the bundled signal fiber (32) pass through the electromagnetic shielding box (34).

6. The plasma edge matter expansion velocity measurement system according to claim 1, characterized in that, The pinhole array target (4) is set up with 4 targets, corresponding to 1 set of standard measurement group and 3 sets of control measurement group; The threshold distance is 1 meter; In the three sets of control measurement groups, the distance from the pinhole array target (4) to the cylindrical wire array load (1) was 4cm to 10cm and was not equal; The vacuum pipe (5) is made of 316L stainless steel with magnetic permeability; The photodetector (21) is a photomultiplier tube; The scintillation detection target chamber (15) is a Y-shaped structure, connected to the tail end of the vacuum pipe (5), and the inner wall is blackened; the mounting plane of the coated modulation scintillator (16) is at a 45-degree angle to the optical axis and is perpendicular to the normal of the receiving plane of the fiber optic beam (18); The electromagnetic shielding box (34) is fully welded for moisture protection, with inner and outer layers insulated and isolated, the inner layer floating and the outer layer grounded; the inner box is independently powered by an uninterruptible power supply; the shielding box door is closed tightly by metal springs, and the gaps in the band tube are tightly sealed with metal cotton.

7. A method for measuring the expansion velocity of plasma edge matter, using the plasma edge matter expansion velocity measurement system according to any one of claims 1-7, characterized in that, Includes the following steps: Step 1: Output transmitted X-rays; The pinhole array targets (4) of the standard measurement group and the control measurement group are placed in their respective vacuum pipes (5), and the distance from the pinhole array target (4) to the cylindrical wire array load (1) is set. The cylindrical wire array load (1) generates radiation, and the high current pulse power device (2) sends a command to the data acquisition system (11), and the data acquisition system (11) starts working; The vacuum tubes (5) of the standard measurement group and the control measurement group output standard transmission X-rays and control transmission X-rays, respectively; Step 2: The signal detection system outputs a pulse electrical signal; Standard X-rays and control X-rays enter their respective signal detection systems (10), and the signal detection systems (10) of the standard measurement group and the control measurement group output standard pulse electrical signals and control pulse electrical signals, respectively. Step 3: Store and output the digital signal; The standard pulse electrical signal and the control pulse electrical signal are respectively entered into their respective data acquisition systems (11). The data acquisition systems (11) of the standard measurement group and the control measurement group convert the pulse electrical signals into standard group digital signals and control group digital signals respectively, store them and output them. Step 4: Extract the plasma expansion velocity information of the edge material; The data acquisition system (11) calculates the curve of the expansion velocity of plasma edge material over time based on the digital signals of the standard group, the digital signals of the control group, the pinhole diameter, and the pinhole spacing.

8. The method for measuring the expansion velocity of plasma edge matter according to claim 7, characterized in that, In step 2, the standard and control X-rays each enter the corresponding scintillation detection target chamber (15) and irradiate the coated modulation scintillator (16); the coated modulation scintillator flattens the energy spectrum response to the incident X-rays and converts it into visible light radiation, and the magnitude of the visible light signal is proportional to the intensity of the X-rays; Visible light enters the fiber optic beam (18) through the quartz glass window (17), and is then split into beams (19) and uniformly dispersed before entering the electromagnetic shielding box (34) through the metal waveguide (20). Visible light is output from the beam splitter end and enters the photodetector (21) after passing through the optical attenuator (31). The photodetector (21) receives optical signals and converts them into electrical signals; In step 3, the electrical signal is transmitted to the data acquisition instrument (27) via the signal cable (23), and the data acquisition instrument simultaneously acquires the electrical signal and converts it into a digital signal under the device trigger command; After conversion, the digital signal is transmitted to the signal receiver (35) through the bundled signal fiber (32); The signal receiver receives digital fiber optic signals and transmits them to the storage module (36) to complete the recording and storage in data text format.

9. The method for measuring the expansion velocity of plasma edge matter according to claim 7, characterized in that, Step 4 further includes: The standard group digital signal and the control group digital signal are time-aligned to obtain the aligned standard group digital signal and the aligned control group digital signal. The aligned standard group digital signal is subtracted from the aligned control group digital signal to obtain the difference digital signal. The difference digital signal is divided by the aligned standard group digital signal to obtain the ratio digital signal. The area of ​​the pinhole region covered by the expansion of the concave-pore plasma is calculated using the ratio digital signal, the pinhole diameter and the pinhole spacing of the pinhole array filter. The expansion distance of the concave-pore plasma is calculated using the area of ​​the covered region and the pinhole diameter of the pinhole array filter. The above calculation process is repeated to obtain the expansion distance curve of the concave-pore plasma at each time point. The slope of the curve at each time point is calculated to obtain the expansion velocity of the concave-pore plasma at each time point.

10. The method for measuring the expansion velocity of plasma edge matter according to claim 7, characterized in that, The control measurement group consists of 3 sets, and the distance from the pinhole array target (4) to the cylindrical wire array load (1) in each set is not equal.

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