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- Cover and Contents
- High Power Laser Physics and Technology
- Inertial Confinement Fusion Physics and Technology
- High Power Microwave Technology
- Particle Beams and Accelerator Technology
- Pulsed Power Technology
- Nuclear Science and Engineering
- Advanced Interdisciplinary Science
- Special Column of 5th Symposium on Frontier of HPLPB
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2025,
37: 1-2.
2025,
37: 081001.
doi: 10.11884/HPLPB202537.250034
Abstract:
Ross pair and filters stack spectrometers are commonly used to detect hard X-ray spectra. The results of filters stack spectrometer are highly sensitive to the profile of the pre-estimated spectrum, while Ross pair is limited to discrete spectrum. Here we provide a Ross pair-filters stack mixed spectrometer, which combines the advantages of traditional filter stack spectrometers and Ross pairs. Each layer of the filter in the traditional filters stack spectrometer has been replaced with a Ross filter pair. Thus, the discrete spectrum given by Ross pair can be used as the pre-estimated spectrum for the filters stack to solve the entire X-ray spectrum. Numerical and physical experiments using X-ray tube confirm that the present mixed spectrometer can provide more accurate spectral structures compared to traditional filter stack spectrometers. The compact and lightweight design make it widely applicable in hard X-ray spectral measurements.
Ross pair and filters stack spectrometers are commonly used to detect hard X-ray spectra. The results of filters stack spectrometer are highly sensitive to the profile of the pre-estimated spectrum, while Ross pair is limited to discrete spectrum. Here we provide a Ross pair-filters stack mixed spectrometer, which combines the advantages of traditional filter stack spectrometers and Ross pairs. Each layer of the filter in the traditional filters stack spectrometer has been replaced with a Ross filter pair. Thus, the discrete spectrum given by Ross pair can be used as the pre-estimated spectrum for the filters stack to solve the entire X-ray spectrum. Numerical and physical experiments using X-ray tube confirm that the present mixed spectrometer can provide more accurate spectral structures compared to traditional filter stack spectrometers. The compact and lightweight design make it widely applicable in hard X-ray spectral measurements.
2025,
37: 081002.
doi: 10.11884/HPLPB202537.250065
Abstract:
As a new type of laser driver for suppressing laser plasma instability, the low-coherence laser driver holds significant research value in the field of laser inertial confinement fusion. To achieve large-bandwidth and high-power low-coherence pulse parametric amplification, this study provides a detailed analysis of the parametric matching characteristics of DKDP crystals with varying deuteration rates under Type-I collinear phase matching conditions. The fundamental parameters, including phase-matching angles, walk-off angles, and parametric bandwidths, are determined. The theoretical parameter bandwidth of the 58% deuterium-doped DKDP crystal is 180 nm. On this basis, a design for broadband low-temporal-coherence optical parametric amplification based on 58% DKDP crystals is proposed, and the theoretical model and the corresponding numerical model are established by the three-wave coupled equations. Furthermore, an experimental investigation of parametric amplification based on 58%-deuterium-doped DKDP crystals is conducted. The center wavelength of the broadband low-coherence signal light is set at1053 nm, while the pump wavelength is fixed at 532 nm. The spectral width is 40 nm with a gain factor of 2.1. The results show that 58% DKDP crystal has a large gain bandwidth, and combined with the colinear phase-matching method, such crystals are expected to enable large-bandwidth and high-gain amplification of low-coherence light.
As a new type of laser driver for suppressing laser plasma instability, the low-coherence laser driver holds significant research value in the field of laser inertial confinement fusion. To achieve large-bandwidth and high-power low-coherence pulse parametric amplification, this study provides a detailed analysis of the parametric matching characteristics of DKDP crystals with varying deuteration rates under Type-I collinear phase matching conditions. The fundamental parameters, including phase-matching angles, walk-off angles, and parametric bandwidths, are determined. The theoretical parameter bandwidth of the 58% deuterium-doped DKDP crystal is 180 nm. On this basis, a design for broadband low-temporal-coherence optical parametric amplification based on 58% DKDP crystals is proposed, and the theoretical model and the corresponding numerical model are established by the three-wave coupled equations. Furthermore, an experimental investigation of parametric amplification based on 58%-deuterium-doped DKDP crystals is conducted. The center wavelength of the broadband low-coherence signal light is set at
2025,
37: 081003.
doi: 10.11884/HPLPB202537.250103
Abstract:
This article mainly investigated the incident and exit surfaces of terbium gallium garnet (TGG) magneto-optical elements by damaged by the laser with wavelength of1064 nm through pump-probe imaging technology. The damage characteristics of terbium gallium garnet elements under fundamental 1064 nm pulsed laser irradiation were studied. The results indicated that the coated TGG element exhibited a lower damage threshold at the incident surface compared with the exit surface, and the difference in damage morphology between the entrance and exit surface was mainly influenced by laser-induced plasma effects. It was found that the initial damage on the TGG incident surface mainly came from impurities and defects in the coatings, and the separation of the film layer under high energy would occur; The exit surface damage of coated TGG components was mainly induced by impurity defects in the substrate material, and the size of damage pits increased gradually under higher laser energy. By analyzing the influence of factors such as laser pulse energy, plasma effect, and material damage response on the laser damage threshold, this study provided important and reference for improving the anti-damage ability of TGG magneto-optical materials under high-power laser irradiation.
This article mainly investigated the incident and exit surfaces of terbium gallium garnet (TGG) magneto-optical elements by damaged by the laser with wavelength of
2025,
37: 081004.
doi: 10.11884/HPLPB202537.250072
Abstract:
To achieve stable transmission of laser with lower loss, single mode, and single polarization in the mid-infrared band, This paper designs a bend-resistant hollow-core anti-resonant fiber configuration with a double-cladding nested structure. The finite element method is used to optimize the structural parameters, and the transmission characteristics of broadband low-loss single polarization of the fiber are verified through simulation. The confinement loss of this fiber is less than 0.01 dB/km within the wavelength range of 2.9−3.3 μm, and the high-order mode extinction ratio exceeds1000 , and the confinement loss is as low as 0.0014 dB/km at 3 μm wavelength. The symmetry of the fiber structure is destroyed by using different nested tube thicknesses, and the single-polarization characteristic of the fiber is theoretically investigated. Within the wavelength range of 2.996−3.004 μm, the polarization extinction ratio exceeds 10000 , demonstrating an extremely stable single polarization effect. In addition, theoretical analysis indicates that this fiber also has excellent bending resistance performance. When the bending radius in the y-direction is greater than 5 cm, it can still ensure single-polarization laser transmission, and the bending loss is less than 3.11 dB/km. The designed hollow-core anti-resonant fiber configuration has great potential for application in mid-infrared fiber laser and other fields.
To achieve stable transmission of laser with lower loss, single mode, and single polarization in the mid-infrared band, This paper designs a bend-resistant hollow-core anti-resonant fiber configuration with a double-cladding nested structure. The finite element method is used to optimize the structural parameters, and the transmission characteristics of broadband low-loss single polarization of the fiber are verified through simulation. The confinement loss of this fiber is less than 0.01 dB/km within the wavelength range of 2.9−3.3 μm, and the high-order mode extinction ratio exceeds
2025,
37: 082001.
doi: 10.11884/HPLPB202537.240429
Abstract:
In experimental studies of indirect drive inertial confinement fusion, both flat-response X-ray detector (FXRD) and space-resolving flux detector (SRFD) are commonly used to measure the radiation flux. The SRFD can measure radiation flux in localized spatial regions, thus avoiding signal disruption from non-targeted regions. However, direct experimental evidence has long been lacking to determine the consistency between SRFD and FXRD. In this paper, we introduce the experimental design of consistency measurement of the SRFD detector and FXRD detector at Shenguang 100 kJ facility, based on a small-plane target, which considers the field-of-view and signal amplitude of the two detectors. The experimental results show that the average difference in the radiation flux obtained by the two detectors is approximately 4.6%, which shows good consistency. Finally, the radiation flux given by the radiation hydrodynamic simulation is reasonably close to the experiment, with some differences in the behavior at the rising edge and decreasing edge. It is possibly related to the details of the simulation model. This work provides a good foundation for experimental studies related to the precision measurement of X-ray radiation flux in a local spatial region.
In experimental studies of indirect drive inertial confinement fusion, both flat-response X-ray detector (FXRD) and space-resolving flux detector (SRFD) are commonly used to measure the radiation flux. The SRFD can measure radiation flux in localized spatial regions, thus avoiding signal disruption from non-targeted regions. However, direct experimental evidence has long been lacking to determine the consistency between SRFD and FXRD. In this paper, we introduce the experimental design of consistency measurement of the SRFD detector and FXRD detector at Shenguang 100 kJ facility, based on a small-plane target, which considers the field-of-view and signal amplitude of the two detectors. The experimental results show that the average difference in the radiation flux obtained by the two detectors is approximately 4.6%, which shows good consistency. Finally, the radiation flux given by the radiation hydrodynamic simulation is reasonably close to the experiment, with some differences in the behavior at the rising edge and decreasing edge. It is possibly related to the details of the simulation model. This work provides a good foundation for experimental studies related to the precision measurement of X-ray radiation flux in a local spatial region.
2025,
37: 082002.
doi: 10.11884/HPLPB202537.250027
Abstract:
To achieve four-phase image registration, an image registration method based on SIFT (scale invariant features transform) algorithm is proposed in this paper. The method is divided into four steps. Firstly, the feature points of the reference image and the misregistration images are extracted respectively. In this step, the characteristics of 2D-velocity interferometry system for any reflector (VISAR) images are fully considered, and homologous non-fringe images are introduced to obtain more accurate results. The second step is feature points matching. After roughly matching, a two-stepfiltering method composed of angle histograms and feature point distance is designed to achieve accurate matching. The third step involves calculating the transformation parameters based on the final matching results. Finally, the transformation parameters are applied to misregistration images for interpolation transformation to achieve image registration. One of the four-phase images is used as the reference image to register the remaining three images. For nonfringe images, experimental results show that the correlation coefficient between registered images and the reference image increases from 0.5 to above 0.9. For fringe images, the calculation accuracy of wrapped phase improves significantly. Therefore, the algorithm in this paper effectively solves the registration problem of 2D-VISAR four-phase images, laying a foundation for further data processing in the future.
To achieve four-phase image registration, an image registration method based on SIFT (scale invariant features transform) algorithm is proposed in this paper. The method is divided into four steps. Firstly, the feature points of the reference image and the misregistration images are extracted respectively. In this step, the characteristics of 2D-velocity interferometry system for any reflector (VISAR) images are fully considered, and homologous non-fringe images are introduced to obtain more accurate results. The second step is feature points matching. After roughly matching, a two-stepfiltering method composed of angle histograms and feature point distance is designed to achieve accurate matching. The third step involves calculating the transformation parameters based on the final matching results. Finally, the transformation parameters are applied to misregistration images for interpolation transformation to achieve image registration. One of the four-phase images is used as the reference image to register the remaining three images. For nonfringe images, experimental results show that the correlation coefficient between registered images and the reference image increases from 0.5 to above 0.9. For fringe images, the calculation accuracy of wrapped phase improves significantly. Therefore, the algorithm in this paper effectively solves the registration problem of 2D-VISAR four-phase images, laying a foundation for further data processing in the future.
2025,
37: 083001.
doi: 10.11884/HPLPB202537.250030
Abstract:
In order to solve the problem of microwave ignition of solid energetic materials under low power conditions, this paper proposes a low-power high-field microwave ignition technology based on dual-focusing optimization design of rectangular resonant cavity. The developed microwave ignition device consists of a solid-state microwave source, a rectangular resonant cavity, a microwave probe and other components. Among them, the rectangular resonant cavity is fed by a probe, and the energy is focused once by resonance. Combined with the distortion effect of the probe tip on the electric field and the compression effect of the metal stage on the electric field distribution space, the secondary focusing of the energy in the cavity during resonance is achieved, and the electromagnetic compatibility design is used to prevent electromagnetic wave leakage. The simulation and experiment show that the microwave ignition device has multiple operating frequency points in the range of 2−3 GHz and the frequency is adjustable. The maximum field strength can reach MV/m level at 22 W power, enabling effective ignition of small black powder. Compared with the existing device, the ignition power is significantly reduced. The developed low-power and high-field microwave ignition technology can provide a platform for the study of microwave ignition of solid energetic materials.
In order to solve the problem of microwave ignition of solid energetic materials under low power conditions, this paper proposes a low-power high-field microwave ignition technology based on dual-focusing optimization design of rectangular resonant cavity. The developed microwave ignition device consists of a solid-state microwave source, a rectangular resonant cavity, a microwave probe and other components. Among them, the rectangular resonant cavity is fed by a probe, and the energy is focused once by resonance. Combined with the distortion effect of the probe tip on the electric field and the compression effect of the metal stage on the electric field distribution space, the secondary focusing of the energy in the cavity during resonance is achieved, and the electromagnetic compatibility design is used to prevent electromagnetic wave leakage. The simulation and experiment show that the microwave ignition device has multiple operating frequency points in the range of 2−3 GHz and the frequency is adjustable. The maximum field strength can reach MV/m level at 22 W power, enabling effective ignition of small black powder. Compared with the existing device, the ignition power is significantly reduced. The developed low-power and high-field microwave ignition technology can provide a platform for the study of microwave ignition of solid energetic materials.
2025,
37: 083002.
doi: 10.11884/HPLPB202537.250059
Abstract:
Microwave plasma has shown significant advantages in the fields of materials synthesis and chemical catalysis due to its high electron density and power utilization efficiency. To solve the problem that the small reaction area of traditional reactor limits its large-scale application, a three-prism microwave plasma reactor structure is innovatively proposed based on the principle of compressed waveguide. The design adopts a three-port symmetric configuration and introduces a compressed waveguide structure inside the cavity to achieve effective superposition and enhancement of the electric field. In addition, the influence of the port positions and microwave phases on the reflection coefficient and electric field distribution characteristics inside the cavity is systematically analyzed by using the multi-physical field coupling calculation method. The results show that optimizing the port position can reduce the reflection coefficient and improve the efficiency of energy utilization, regulating the port phase can effectively enhance the superposition effect of the electric field, so that the electric field is concentrated and widely distributed in the area of the quartz tube, and the peak field strength is as high as 1.64×105 V/m, which can satisfy the excitation conditions of the large-area plasma, providing a reference for the subsequent research on microwave plasma chemical reaction.
Microwave plasma has shown significant advantages in the fields of materials synthesis and chemical catalysis due to its high electron density and power utilization efficiency. To solve the problem that the small reaction area of traditional reactor limits its large-scale application, a three-prism microwave plasma reactor structure is innovatively proposed based on the principle of compressed waveguide. The design adopts a three-port symmetric configuration and introduces a compressed waveguide structure inside the cavity to achieve effective superposition and enhancement of the electric field. In addition, the influence of the port positions and microwave phases on the reflection coefficient and electric field distribution characteristics inside the cavity is systematically analyzed by using the multi-physical field coupling calculation method. The results show that optimizing the port position can reduce the reflection coefficient and improve the efficiency of energy utilization, regulating the port phase can effectively enhance the superposition effect of the electric field, so that the electric field is concentrated and widely distributed in the area of the quartz tube, and the peak field strength is as high as 1.64×105 V/m, which can satisfy the excitation conditions of the large-area plasma, providing a reference for the subsequent research on microwave plasma chemical reaction.
2025,
37: 083003.
doi: 10.11884/HPLPB202537.250010
Abstract:
Microstrip traveling wave tubes (TWTs) have garnered significant attention due to their potential applications in communication, defense, and industrial systems. This paper presents a compact W-band dual-channel TWT, utilizing a U-shaped microstrip meander-line slow-wave structure (SWS). High-frequency characteristics are analyzed through simulation and cold tests. The results demonstrate that adjusting structural parameters effectively optimizes the S-parameters. Particle-in-cell (PIC) simulations with an 18.8 kV, 0.1 A electron beam predict an output power of 18 W with a gain of 14 dB. Experimental measurements of S-parameters are conducted using three substrate materials: Rogers 5880, quartz, and diamond. The quartz substrate exhibits the closest agreement with simulation results. The results advance the development of the microstrip-based TWTs for high-data-rate communication systems.
2025,
37: 083004.
doi: 10.11884/HPLPB202537.250062
Abstract:
To address the electromagnetic pulse protection requirements of the RF front-end in a complex electromagnetic environment, a strong electromagnetic pulse protection circuit working in the L-band is designed. This circuit uses PIN diode as the core device, adopts a multi-level PIN diode cascaded protection structure, connects each stage through microstrip transmission lines, and optimizes the design. The performance of the circuit under different working conditions is verified by simulation, and its physical test is carried out. The test results show that in the L-band, its insertion loss is less than 0.6 dB, the return loss is more than 11.93 dB, and the standing wave ratio is less than 1.68, indicating good signal transmission performance. Under the injection of a 4 kV square wave pulse, the circuit can respond quickly within 1 ns, and the peak leakage voltage generated by the circuit is 69.636 V. After 2 ns, the stable output voltage of the circuit is less than 20 V, indicating that the circuit has good transient protection capability against fast-edge pulse. Combined with the low-loss characteristics in L-band, the circuit can provide effective electromagnetic pulse protection support for equipment working in L-band.
To address the electromagnetic pulse protection requirements of the RF front-end in a complex electromagnetic environment, a strong electromagnetic pulse protection circuit working in the L-band is designed. This circuit uses PIN diode as the core device, adopts a multi-level PIN diode cascaded protection structure, connects each stage through microstrip transmission lines, and optimizes the design. The performance of the circuit under different working conditions is verified by simulation, and its physical test is carried out. The test results show that in the L-band, its insertion loss is less than 0.6 dB, the return loss is more than 11.93 dB, and the standing wave ratio is less than 1.68, indicating good signal transmission performance. Under the injection of a 4 kV square wave pulse, the circuit can respond quickly within 1 ns, and the peak leakage voltage generated by the circuit is 69.636 V. After 2 ns, the stable output voltage of the circuit is less than 20 V, indicating that the circuit has good transient protection capability against fast-edge pulse. Combined with the low-loss characteristics in L-band, the circuit can provide effective electromagnetic pulse protection support for equipment working in L-band.
2025,
37: 084001.
doi: 10.11884/HPLPB202537.250082
Abstract:
As accelerators increase in scale and complexity, their control networks face challenges such as device proliferation, security management difficulties, and low maintenance efficiency. To address these issues, a control network management system for large-scale accelerators was designed and developed. This system implements three functions: centralized management of control network IP addresses, automated collection of dynamic network information, and network access control. The system prevents IP conflicts through a centralized application and approval mechanism, enables real-time monitoring of device status and precise physical location identification based on switch operational data, and enhances control network access security through IP and port binding. The system is built on a web. architecture, with a front-end developed using the Vue.js framework and a back-end utilizing a hybrid technology stack of Node.js and Python, while MongoDB is employed for data storage. This system has been successfully deployed and is operating stably in the China Spallation Neutron Source (CSNS) accelerator control network, effectively addressing security vulnerabilities and maintenance challenges in network management. It has also established a foundation for network management in CSNS-II.
As accelerators increase in scale and complexity, their control networks face challenges such as device proliferation, security management difficulties, and low maintenance efficiency. To address these issues, a control network management system for large-scale accelerators was designed and developed. This system implements three functions: centralized management of control network IP addresses, automated collection of dynamic network information, and network access control. The system prevents IP conflicts through a centralized application and approval mechanism, enables real-time monitoring of device status and precise physical location identification based on switch operational data, and enhances control network access security through IP and port binding. The system is built on a web. architecture, with a front-end developed using the Vue.js framework and a back-end utilizing a hybrid technology stack of Node.js and Python, while MongoDB is employed for data storage. This system has been successfully deployed and is operating stably in the China Spallation Neutron Source (CSNS) accelerator control network, effectively addressing security vulnerabilities and maintenance challenges in network management. It has also established a foundation for network management in CSNS-II.
Design and validation of a proton beam line based on a rapid-cycling synchrotron for Flash radiation
2025,
37: 084002.
doi: 10.11884/HPLPB202537.250003
Abstract:
We have designed a proton beamline based on a rapid-cycling synchrotron for Flash radiation with ultra-high dose rate. Because proton beams can be extracted within hundreds of nanoseconds in the rapid-cycling synchrotron, its energy can be altered from one cycle to the next with different extraction time. The intended beamline system can achieve layer stacking irradiation at an instantaneous dose rate of 107 Gy/s. Each longitudinal layer requires a different beam intensity. The target is divided longitudinally into different layers, each of which needs a different beam energy, to produce a uniform irradiation field. The system, including a double scatter system, a range compensator, a ripple filter, and a multi-leaf collimator to maximize proton fluence into the target, is simulated using the Monte Carlo software FLUKA. Three different kinds of ripple filters are built for the low, medium, and high energy zones based on the original Bragg peaks to reduce the number of energy layers and shorten the total irradiation duration. These filters transform the spike region into a Gaussian distribution with flat expansion areas of 2 cm, 6 cm, and 20 cm, respectively. Combining the rapid-cycling synchrotron with the layer stacking irradiation provides a novel method for achieving Flash proton irradiation, which delivers an ultra-high dose rate to the target.
We have designed a proton beamline based on a rapid-cycling synchrotron for Flash radiation with ultra-high dose rate. Because proton beams can be extracted within hundreds of nanoseconds in the rapid-cycling synchrotron, its energy can be altered from one cycle to the next with different extraction time. The intended beamline system can achieve layer stacking irradiation at an instantaneous dose rate of 107 Gy/s. Each longitudinal layer requires a different beam intensity. The target is divided longitudinally into different layers, each of which needs a different beam energy, to produce a uniform irradiation field. The system, including a double scatter system, a range compensator, a ripple filter, and a multi-leaf collimator to maximize proton fluence into the target, is simulated using the Monte Carlo software FLUKA. Three different kinds of ripple filters are built for the low, medium, and high energy zones based on the original Bragg peaks to reduce the number of energy layers and shorten the total irradiation duration. These filters transform the spike region into a Gaussian distribution with flat expansion areas of 2 cm, 6 cm, and 20 cm, respectively. Combining the rapid-cycling synchrotron with the layer stacking irradiation provides a novel method for achieving Flash proton irradiation, which delivers an ultra-high dose rate to the target.
2025,
37: 085001.
doi: 10.11884/HPLPB202537.250021
Abstract:
This paper proposes a miniaturized impulse voltage generator that differs from the traditional gas ball gap. It adopts a modular multi-stage structure, using the Marx topology as the main circuit and MOSFET as the main switch. MATLAB is used to fit and modulate lightning impulses or chopped lightning impulses through the nearest-level forced modulation algorithm (NLM). an FPGA controls the modular impulse voltage generator to generate impulse voltage waveforms such as charging voltage, wavefront time, wave tail time, and truncation time, all of wich can be flexibly adjusted by the host computer. The test results show that the maximum output voltage of a single impulse voltage module is 24 kV, with a total of 30 stages of voltage output. When 5 impulse voltage modules are operated in series, a maximum of 150 stages of different voltages can be generated, and the peak voltage can reach −100 kV lightning impulses or chopped lightning impulses.
This paper proposes a miniaturized impulse voltage generator that differs from the traditional gas ball gap. It adopts a modular multi-stage structure, using the Marx topology as the main circuit and MOSFET as the main switch. MATLAB is used to fit and modulate lightning impulses or chopped lightning impulses through the nearest-level forced modulation algorithm (NLM). an FPGA controls the modular impulse voltage generator to generate impulse voltage waveforms such as charging voltage, wavefront time, wave tail time, and truncation time, all of wich can be flexibly adjusted by the host computer. The test results show that the maximum output voltage of a single impulse voltage module is 24 kV, with a total of 30 stages of voltage output. When 5 impulse voltage modules are operated in series, a maximum of 150 stages of different voltages can be generated, and the peak voltage can reach −100 kV lightning impulses or chopped lightning impulses.
Measurement method for areal density of pulsed X-ray photographic images in metal ejection diagnosis
2025,
37: 085002.
doi: 10.11884/HPLPB202537.250025
Abstract:
The ejection phenomenon generated by metal materials under strong impact is an important issue in the field of impact compression research. Pulsed X-ray photography is an important diagnostic testing method for micro jet processes. The use of X-ray images to obtain the surface density of metal material experimental objects and jets under strong impact is an important objective of this type of experiment. A method for measuring the areal density data of ejection X-ray images based on stepped wedges is proposed. The method reduces the influence of white spot noise by median filtering, corrects the unevenness of light field distribution and detector response by using empty field images and obtains the system point spread function by imaging the Roll-Bar object, and uses the imaging system point spread function and an improved Tikhonov regularization based image restoration method to reduce the impact of blur on X-ray images. The processing flow for obtaining the areal density information of ejection X-ray images is provided. The verification of the inversion of areal density in static object experimental images shows that the proposed method can accurately obtain the areal density information of metal ejection experimental X-ray images.
The ejection phenomenon generated by metal materials under strong impact is an important issue in the field of impact compression research. Pulsed X-ray photography is an important diagnostic testing method for micro jet processes. The use of X-ray images to obtain the surface density of metal material experimental objects and jets under strong impact is an important objective of this type of experiment. A method for measuring the areal density data of ejection X-ray images based on stepped wedges is proposed. The method reduces the influence of white spot noise by median filtering, corrects the unevenness of light field distribution and detector response by using empty field images and obtains the system point spread function by imaging the Roll-Bar object, and uses the imaging system point spread function and an improved Tikhonov regularization based image restoration method to reduce the impact of blur on X-ray images. The processing flow for obtaining the areal density information of ejection X-ray images is provided. The verification of the inversion of areal density in static object experimental images shows that the proposed method can accurately obtain the areal density information of metal ejection experimental X-ray images.
2025,
37: 085003.
doi: 10.11884/HPLPB202537.250102
Abstract:
Deionized water, commonly used as insulating dielectric in pulse-forming lines or transmission lines of high-power pulse devices, offers advantages such as a high dielectric constant, high breakdown strength, good self-healing properties, and low cost. However, the solid insulation barriers in deionized water, which support the inner cylinder and provide physical isolation between different dielectrics at the front and rear ends, are often the weak points in high-voltage insulation systems. To investigate the surface flashover characteristics of typical solid insulation materials in deionized water, this study utilized a high-voltage insulation experimental platform with a maximum operating voltage of approximately 900 kV and a pulse rise time of about 100 ns. The study focused on four common solid insulation materials: MC Nylon, polymethyl methacrylate (PMMA), cross-linked polystyrene (CLPS), and high-density polyethylene (HDPE). Using circular plate electrodes and cylindrical samples, the experiments examined the effects of sample material, thickness, voltage duration and surface roughness on flashover voltage and electric field strength. Results show that as the sample thickness increases from 0.5 cm to 2 cm, the flashover voltage increases linearly, while the flashover field strength decreases exponentially. For different materials, the flashover voltage and field strength follow the order: MC Nylon ≥ PMMA > CLPS > HDPE. As the voltage application time shortens, the flashover voltage gradually increases. When the voltage application time is within 100 ns, the flashover voltage remains basically stable. Furthermore, when the surface roughness of the solid material increases from 1.6 μm to 12.5 μm, no significant change in flashover field strength is observed. Based on a comprehensive analysis of flashover field strength data and impact resistance characteristics, MC Nylon demonstrates the best overall.
Deionized water, commonly used as insulating dielectric in pulse-forming lines or transmission lines of high-power pulse devices, offers advantages such as a high dielectric constant, high breakdown strength, good self-healing properties, and low cost. However, the solid insulation barriers in deionized water, which support the inner cylinder and provide physical isolation between different dielectrics at the front and rear ends, are often the weak points in high-voltage insulation systems. To investigate the surface flashover characteristics of typical solid insulation materials in deionized water, this study utilized a high-voltage insulation experimental platform with a maximum operating voltage of approximately 900 kV and a pulse rise time of about 100 ns. The study focused on four common solid insulation materials: MC Nylon, polymethyl methacrylate (PMMA), cross-linked polystyrene (CLPS), and high-density polyethylene (HDPE). Using circular plate electrodes and cylindrical samples, the experiments examined the effects of sample material, thickness, voltage duration and surface roughness on flashover voltage and electric field strength. Results show that as the sample thickness increases from 0.5 cm to 2 cm, the flashover voltage increases linearly, while the flashover field strength decreases exponentially. For different materials, the flashover voltage and field strength follow the order: MC Nylon ≥ PMMA > CLPS > HDPE. As the voltage application time shortens, the flashover voltage gradually increases. When the voltage application time is within 100 ns, the flashover voltage remains basically stable. Furthermore, when the surface roughness of the solid material increases from 1.6 μm to 12.5 μm, no significant change in flashover field strength is observed. Based on a comprehensive analysis of flashover field strength data and impact resistance characteristics, MC Nylon demonstrates the best overall.
2025,
37: 086001.
doi: 10.11884/HPLPB202537.240430
Abstract:
The X-ray beam position monitor (XBPM) can be used to measure the position of beamline synchrotron radiation light. The front-end acquisition circuit of XBPM is mainly used for analog signal acquisition and processing. To meet the demand for precise measurement of synchrotron light position information in the beamline front-end area of high energy photo source (HEPS), an XBPM electronic analog front end (AFE) board card has been developed in this paper. The functions such as current-voltage conversion, range switching, gain control and ADC sampling of XBPM signals were designed and implemented, and a laboratory test platform was built to conduct performance tests on XBPM-AFE. The test results show that the current input range of the I/V conversion module is from 10 nA to 1 mA. When the input current varies by three orders of magnitude, the linear error of the transimmer gain in each range segment remains at a relatively low level. The average relative standard deviation of the measurement results among the four channels is less than 0.46%. The analog-to-digital conversion module can accurately reflect the signal input conditions with changing speeds of over 0.1 s and 1 ms respectively in both slow acquisition and fast acquisition modes.
The X-ray beam position monitor (XBPM) can be used to measure the position of beamline synchrotron radiation light. The front-end acquisition circuit of XBPM is mainly used for analog signal acquisition and processing. To meet the demand for precise measurement of synchrotron light position information in the beamline front-end area of high energy photo source (HEPS), an XBPM electronic analog front end (AFE) board card has been developed in this paper. The functions such as current-voltage conversion, range switching, gain control and ADC sampling of XBPM signals were designed and implemented, and a laboratory test platform was built to conduct performance tests on XBPM-AFE. The test results show that the current input range of the I/V conversion module is from 10 nA to 1 mA. When the input current varies by three orders of magnitude, the linear error of the transimmer gain in each range segment remains at a relatively low level. The average relative standard deviation of the measurement results among the four channels is less than 0.46%. The analog-to-digital conversion module can accurately reflect the signal input conditions with changing speeds of over 0.1 s and 1 ms respectively in both slow acquisition and fast acquisition modes.
2025,
37: 089001.
doi: 10.11884/HPLPB202537.250188
Abstract:
Facing the urgent demand for high-performance, customized electromagnetic protection materials driven by increasingly intelligent electronic information systems, traditional research and development (R&D) models face severe limitations due to complex multi-parameter coupling, high trial-and-error costs, and difficulties in cross-scale design, hindering their ability to meet the need for efficient R&D. Artificial intelligence (AI), leveraging data-driven approaches and algorithmic optimization, offers a transformative paradigm to overcome these limitations. This paper systematically reviews AI-empowered research in electromagnetic protection materials. It begins by analyzing the key characteristics and core challenges in the R&D of these materials, highlighting the high suitability of AI for this domain. Subsequently, it illustrates representative research cases from both forward prediction and inverse design perspectives within the field. Finally, the paper identifies existing challenges concerning data availability, physical interpretability of AI models, and practical application deployment barriers. Specific considerations are proposed in three aspects: constructing specialized electromagnetic material gene databases, developing physics-informed neural networks that integrate data with physical principles, and emphasizing the need to promote domain-specific data sharing and establish standardized protocols, so as to pave the way for the intelligent development of next-generation electromagnetic protection materials.
Facing the urgent demand for high-performance, customized electromagnetic protection materials driven by increasingly intelligent electronic information systems, traditional research and development (R&D) models face severe limitations due to complex multi-parameter coupling, high trial-and-error costs, and difficulties in cross-scale design, hindering their ability to meet the need for efficient R&D. Artificial intelligence (AI), leveraging data-driven approaches and algorithmic optimization, offers a transformative paradigm to overcome these limitations. This paper systematically reviews AI-empowered research in electromagnetic protection materials. It begins by analyzing the key characteristics and core challenges in the R&D of these materials, highlighting the high suitability of AI for this domain. Subsequently, it illustrates representative research cases from both forward prediction and inverse design perspectives within the field. Finally, the paper identifies existing challenges concerning data availability, physical interpretability of AI models, and practical application deployment barriers. Specific considerations are proposed in three aspects: constructing specialized electromagnetic material gene databases, developing physics-informed neural networks that integrate data with physical principles, and emphasizing the need to promote domain-specific data sharing and establish standardized protocols, so as to pave the way for the intelligent development of next-generation electromagnetic protection materials.
2025,
37: 089002.
doi: 10.11884/HPLPB202537.250063
Abstract:
With the rapid development of science and technology, high-speed optical imaging and ultrafast diagnostic techniques have become increasingly important in various fields such as science, industry, defense, and medicine. As an ultrafast optical phenomenon detection instrument, the synchroscan streak camera, when used in conjunction with high-repetition-rate lasers, can achieve high-precision time-synchronized pump-probe experiments. By accumulating and amplifying weak optical signals, it enables high signal-to-noise ratio detection. However, existing synchronous scanning circuits, when operating in long-term mode, accumulate high-frequency noise from signal source devices, and there is a lack of specific impedance matching design methods, which affects the improvement of the time resolution performance of streak camera. This paper comprehensively considers various transformer structures and design schemes, and conducts resonant matching design based on spiral resonators. Through finite element simulation, relevant simulation studies are carried out. By adjusting the parameters of the primary coil of the resonator, the output impedance of the RF power amplifier and the capacitive load are matched. The resonant coupling boost study of the design model shows that a high peak voltage can be output under a certain power input, verifying the effectiveness of the spiral resonant method. The comparative analysis of noise response and time jitter indicates that the design method can further enhance the time resolution performance of synchronous scanning. resolution performance of synchronous scanning.
With the rapid development of science and technology, high-speed optical imaging and ultrafast diagnostic techniques have become increasingly important in various fields such as science, industry, defense, and medicine. As an ultrafast optical phenomenon detection instrument, the synchroscan streak camera, when used in conjunction with high-repetition-rate lasers, can achieve high-precision time-synchronized pump-probe experiments. By accumulating and amplifying weak optical signals, it enables high signal-to-noise ratio detection. However, existing synchronous scanning circuits, when operating in long-term mode, accumulate high-frequency noise from signal source devices, and there is a lack of specific impedance matching design methods, which affects the improvement of the time resolution performance of streak camera. This paper comprehensively considers various transformer structures and design schemes, and conducts resonant matching design based on spiral resonators. Through finite element simulation, relevant simulation studies are carried out. By adjusting the parameters of the primary coil of the resonator, the output impedance of the RF power amplifier and the capacitive load are matched. The resonant coupling boost study of the design model shows that a high peak voltage can be output under a certain power input, verifying the effectiveness of the spiral resonant method. The comparative analysis of noise response and time jitter indicates that the design method can further enhance the time resolution performance of synchronous scanning. resolution performance of synchronous scanning.
2025,
37: 089003.
doi: 10.11884/HPLPB202537.250045
Abstract:
In view of the limitations associated with traditional single-spot laser solid-state phase transformation temperature control methods in complex curved workpieces, this paper proposes a multi-input multi-output (MIMO) temperature decoupling control strategy based on active disturbance rejection control (ADRC). first, a finite element model of multi-spot laser-induced solid-state phase transformation was developed, and a model-order reduction method was applied to extract the key dynamic characteristics of the system, significantly reducing computational complexity and laying a foundation for effective control. Subsequently, to address the high-frequency jitter problem encountered by the conventional fal function within small-error regions, an improved bfal function based on Bernstein polynomials was proposed, thereby enhancing system observation accuracy and disturbance rejection capability. Moreover, an improved particle swarm optimization (PSO) algorithm was used to tune the parameter of ADRC controllers, effectively accelerating the optimization process. Finally, co-simulations conducted on the MATLAB/Simulink and COMSOL platforms demonstrated that the proposed PSO-ADRC controller achieves superior performance in terms of response speed, overshoot reduction, and steady-state accuracy compared to the conventional PID and standard ADRC methods. The method thus provides an efficient and precise solution for multi-spot laser solid-state phase transformation temperature control in complex curved workpieces.
In view of the limitations associated with traditional single-spot laser solid-state phase transformation temperature control methods in complex curved workpieces, this paper proposes a multi-input multi-output (MIMO) temperature decoupling control strategy based on active disturbance rejection control (ADRC). first, a finite element model of multi-spot laser-induced solid-state phase transformation was developed, and a model-order reduction method was applied to extract the key dynamic characteristics of the system, significantly reducing computational complexity and laying a foundation for effective control. Subsequently, to address the high-frequency jitter problem encountered by the conventional fal function within small-error regions, an improved bfal function based on Bernstein polynomials was proposed, thereby enhancing system observation accuracy and disturbance rejection capability. Moreover, an improved particle swarm optimization (PSO) algorithm was used to tune the parameter of ADRC controllers, effectively accelerating the optimization process. Finally, co-simulations conducted on the MATLAB/Simulink and COMSOL platforms demonstrated that the proposed PSO-ADRC controller achieves superior performance in terms of response speed, overshoot reduction, and steady-state accuracy compared to the conventional PID and standard ADRC methods. The method thus provides an efficient and precise solution for multi-spot laser solid-state phase transformation temperature control in complex curved workpieces.
2025,
37: 083005.
doi: 10.11884/HPLPB202537.250089
Abstract:
This paper proposes a compact Q-band relativistic backward wave oscillator (RBWO) operating at low magnetic fields, aiming to advance the miniaturization of high-power microwave (HPM) sources. The device consists of a resonant cavity reflector and two sections of periodic slow-wave structures (SWS), designed in a coaxial configuration. By exploiting the inherent characteristics of the coaxial structure, an optimal inner diameter was selected to enhance power handling capacity while mitigating space charge effects induced by the reduced device size. Through comprehensive simulation and optimization, the device achieved a microwave output power of 470 MW with an efficiency of 39.1% under operational conditions of a guiding magnetic field (0.9 T), a diode voltage of 400 kV, and a beam current of 3 kA. The generated microwave signal exhibited a central frequency of 45 GHz.
This paper proposes a compact Q-band relativistic backward wave oscillator (RBWO) operating at low magnetic fields, aiming to advance the miniaturization of high-power microwave (HPM) sources. The device consists of a resonant cavity reflector and two sections of periodic slow-wave structures (SWS), designed in a coaxial configuration. By exploiting the inherent characteristics of the coaxial structure, an optimal inner diameter was selected to enhance power handling capacity while mitigating space charge effects induced by the reduced device size. Through comprehensive simulation and optimization, the device achieved a microwave output power of 470 MW with an efficiency of 39.1% under operational conditions of a guiding magnetic field (0.9 T), a diode voltage of 400 kV, and a beam current of 3 kA. The generated microwave signal exhibited a central frequency of 45 GHz.
2025,
37: 086002.
doi: 10.11884/HPLPB202537.250100
Abstract:
This study establishes a thermal radiation pulse transport model to quantify the energy release rate and cumulative energy of thermal radiation across temporal variations, spectral bands, and propagation distances through dimensionless processing and numerical simulations. Special emphasis is placed on analyzing the influence of atmospheric transmittance and air density ratios on the spatial distribution of thermal radiation energy, revealing the propagation characteristics of strong explosion-induced thermal radiation in spatial transmission and its wavelength dependency. The results demonstrate that temporally, the cumulative thermal radiation energy increases with time while exhibiting a gradually decreasing growth rate. During the fireball re-ignition phase, the visible band contributes a marginally higher proportion to cumulative energy, whereas the infrared band dominates during the cooling phase. Spatially, the thermal radiation energy decreases with lower altitude as propagation distance extends, until reaching a stabilization threshold where the spatial distribution becomes relatively constant. The developed model enables prediction of thermal radiation energy distribution at specific locations under arbitrary explosion conditions, providing theoretical support for protective design of wavelength-sensitive materials.
This study establishes a thermal radiation pulse transport model to quantify the energy release rate and cumulative energy of thermal radiation across temporal variations, spectral bands, and propagation distances through dimensionless processing and numerical simulations. Special emphasis is placed on analyzing the influence of atmospheric transmittance and air density ratios on the spatial distribution of thermal radiation energy, revealing the propagation characteristics of strong explosion-induced thermal radiation in spatial transmission and its wavelength dependency. The results demonstrate that temporally, the cumulative thermal radiation energy increases with time while exhibiting a gradually decreasing growth rate. During the fireball re-ignition phase, the visible band contributes a marginally higher proportion to cumulative energy, whereas the infrared band dominates during the cooling phase. Spatially, the thermal radiation energy decreases with lower altitude as propagation distance extends, until reaching a stabilization threshold where the spatial distribution becomes relatively constant. The developed model enables prediction of thermal radiation energy distribution at specific locations under arbitrary explosion conditions, providing theoretical support for protective design of wavelength-sensitive materials.
2025,
37: 086003.
doi: 10.11884/HPLPB202537.250083
Abstract:
Artificial radiation belts pose potential threats to spacecraft longevity and performance. High-latitude detonation points can inject large quantities of high-energy particles into Earth's outer radiation belt, which is more susceptible to geomagnetic disturbances compared to the inner radiation belt. Understanding the effects of geomagnetic activity on these particles is of significant importance. This study aims to investigate the diffusion and evolution patterns of electrons in high-L-shell artificial radiation belts under geomagnetic activity, analyzing how geomagnetic disturbances influence electron distribution and decay processes to provide theoretical foundations for spacecraft protection. A three-dimensional artificial radiation belt model was developed based on the VERB3D framework. Numerical simulations were conducted to examine electron diffusion and evolution across three parameters: radial distance, energy, and pitch angle. The analysis focused on geomagnetic effects on plasmasphere morphology, wave field intensity, and wave-particle interactions. Intense geomagnetic activity not only caused significant inward contraction of the plasmasphere but also exponentially enhanced wave field intensities both inside and outside the plasmasphere. This accelerated the diffusion process of artificial radiation belt electrons, leading to rapid flux attenuation and achieving stable distribution states in radial distance, energy, and pitch angle within a relatively short timeframe. However, under sustained geomagnetic influence, the flux of stably distributed high-energy electrons continued to decline. Geomagnetic activity can significantly accelerate the diffusion and decay processes of artificial radiation belts, thereby reducing their hazardous effects on spacecraft. These findings provide new theoretical foundations for spacecraft protection design and hold important reference value for space environment safety assurance.
Artificial radiation belts pose potential threats to spacecraft longevity and performance. High-latitude detonation points can inject large quantities of high-energy particles into Earth's outer radiation belt, which is more susceptible to geomagnetic disturbances compared to the inner radiation belt. Understanding the effects of geomagnetic activity on these particles is of significant importance. This study aims to investigate the diffusion and evolution patterns of electrons in high-L-shell artificial radiation belts under geomagnetic activity, analyzing how geomagnetic disturbances influence electron distribution and decay processes to provide theoretical foundations for spacecraft protection. A three-dimensional artificial radiation belt model was developed based on the VERB3D framework. Numerical simulations were conducted to examine electron diffusion and evolution across three parameters: radial distance, energy, and pitch angle. The analysis focused on geomagnetic effects on plasmasphere morphology, wave field intensity, and wave-particle interactions. Intense geomagnetic activity not only caused significant inward contraction of the plasmasphere but also exponentially enhanced wave field intensities both inside and outside the plasmasphere. This accelerated the diffusion process of artificial radiation belt electrons, leading to rapid flux attenuation and achieving stable distribution states in radial distance, energy, and pitch angle within a relatively short timeframe. However, under sustained geomagnetic influence, the flux of stably distributed high-energy electrons continued to decline. Geomagnetic activity can significantly accelerate the diffusion and decay processes of artificial radiation belts, thereby reducing their hazardous effects on spacecraft. These findings provide new theoretical foundations for spacecraft protection design and hold important reference value for space environment safety assurance.
