In laser-driven inertial confinement fusion experiments, the CR-39 detector, a commonly-used recording medium for proton energy spectrum diagnosis, has timeliness and consistency flaws in energy spectrum measurement. However, the Timepix detector with the ability to obtain online signals can overcome these problems. To apply the Timepix detector to detect implosion proton energy spectra, it is essential to study the response of the Timepix detector to proton energies and incident angles. This work analyzes the response of the Timepix detector to proton beams in different energies and incident angles within the Allpix2 framework using Monte Carlo methods. The simulation results show that the response of the Timepix detector to proton beams in different energies and incident angles exhibits significant differences in cluster morphology, cluster size distribution, and cluster charge distribution. When incident proton beam energy is below 6 MeV, the Timepix detector exhibits high detection efficiency, and the angle of proton incidence does not significantly affect the energy response of the detector.

CUP-VISAR system is a new technology that combines Compressed Ultrafast Photography (CUP) with two-dimensional Velocity Interferometer System for Any Reflector (VISAR). To solve the problem that the image reconstruction quality of CUP-VISAR system decreases obviously under the condition of large noise, a compressed ultrafast photography reconstruction method based on iteration-interframe dual prediction is proposed. Using this method, the correlation of inter-frame image data and the correlation of iterations before and after the same frame image are studied. The compressed image reconstruction problem is presented as an iteration-inter frame dual prediction optimization problem based on Kalman prediction and inter-frame prediction, and the Plug-and-Play Generalized Alternating Projection (PnP-GAP) framework is used to solve the optimization problem effectively. Simulation results show that the minimum Peak Signal-to-Noise Ratio (PSNR) and minimum Structure Similarity Index Measure (SSIM) of the proposed method are increased by 3.18-2.11 dB and 20.30%-8.22% under large Gaussian noise conditions. The practical results show that the proposed method can obtain higher definition of fringe image, and the reconstructed line-VISAR (1D-VISAR) fringe movement trend is clearer, which verifies the effectiveness of the algorithm.

In large current accelerator beam tubes, high-frequency fields are generated when charged particles circulate within the beam pipe. To mitigate the impact on beam current, it is essential to use high-order mode damper to convert the high field energy into heat, which can then be dissipated by a cooling system. This paper presents the research, fabrication, and key performance characteristics of a hybrid high-order mode damper. The absorbing materials utilized in the damper include ferrite and silicon carbide, which can be welded to metal substrates through metallization and welding techniques. Microwave performance simulations and thermal simulations were conducted using CST and COMSOL software, respectively, leading to an optimized damper structure. Test results demonstrate that the absorption efficiency of the hybrid damper aligns closely with the calculated values in the frequency range below 1.7 GHz. However, the simulated absorption efficiency exceeds the measured results significantly above 1.7 GHz. Additionally, the vacuum leak rates, ultimate vacuum, and water resistance meet the design requirements for superconducting high-frequency cavities.

Aiming at the problems of high failure rate, difficult maintenance, poor flexibility, and dangerous manual operation of the traditional stand-alone control of the proton beam irradiation thorium target loading and unloading system under the operating environment of low radiation, large scale, and high complexity, a control method of digital twin proton beam irradiation thorium target loading and unloading system based on the redundancy of Programmable Logic Controller (PLC) is proposed. Firstly, the method adopts a multifactor coordinated control strategy such as CPU redundancy, I/O redundancy, and power supply redundancy, and enables the control system to run uninterruptedly by constructing a hardware hot-standby redundancy system and organizing, programming, and simulating a software redundancy system. Secondly, based on the architecture of “NX MCD+PLC SIM+OPC”, the control system of digital twin virtual-reality interaction is designed, and the twin model of target loading/unloading system is constructed in the virtual space for the data information in the physical space, so as to realize the unattended and continuous monitoring in the radiation environment. Finally, experiments and reliability analysis, prove that the proposed method improves the stability of this control system to 99%, which provides a new idea for the control of operating system under irradiation environment.

Due to the comprehensive performance advantages, GaN-based power devices are more suitable for the future development needs of RF power amplifier modules in the space equipment such as satellite electronic systems．Therefore, the degradation of electrical characteristics and damage mechanism of the enhancement-mode Cascode structure GaN HEMT devices were studied by irradiation experiments with 5 MeV, 60 MeV and 300 MeV protons at the irradiation dose of 2×1012～1×1014 cm-2. The experimental results show that when the irradiation dose is 2×1012 cm-2, the threshold voltage of the Cascode structure GaN HEMT device is significantly reduced, the transconductance peak is negatively drifted and the peak transconductance is reduced, the saturated drain current is significantly increased, and the gate leakage current has no significant change. When the irradiation dose reaches 1×1013 cm-2, the degradation of electrical properties is inhibited and tends to saturate. It is concluded that the cascaded silicon MOSFET in the Cascode structure GaN HEMT is the internal cause of threshold voltage negative drift and drain current increase after proton irradiation. Combined with low-frequency noise test analysis, it is found that the higher the proton irradiation dose, the larger the noise power spectral density of the device, indicating that the more defects introduced by irradiation, the more serious the irradiation damage. Compared with the results of 60 MeV and 300 MeV proton irradiation, the degradation of electrical characteristics of the device after 5 MeV proton irradiation is the most serious. SRIM simulation results show that the lower the proton irradiation energy, the greater the number of vacancies (gallium vacancy is dominated), and the more significant the degradation of electrical characteristics of the device.

Photocathode electron sources play a crucial role in advanced accelerator facilities. Recent advancements in electron accelerator facilities have continually pushed the parameter boundaries of electron sources, which in turn necessitate photocathode drive lasers that possess high power, high stability, and the ability to control spatiotemporal distributions. For such a purpose, lots of efforts have been made to achieve high-quality amplification, harmonic generation, and spatiotemporal shaping of the drive laser systems. This paper presents a comprehensive review of the primary technological approaches and status of drive lasers for high-brightness electron sources worldwide. Analysis of representative drive laser schemes and discussion on the future trends are also included, aiming to provide a helpful reference for planning and developing high-performance photocathode drive laser system.

Compared with vacuum tank system, supersonic injection technology has significant advantages in pressure recovery of chemical laser weapons, among them, the supersonic center injector has greater injection potential due to its smaller total pressure loss. Simulation and experimental studies were conducted on the supersonic center injector. The results show that for the supersonic center injector with a contraction-type mixing chamber, although it is easier to reach the working state, it is not superior to the straight-type injector under the condition of fixed injection coefficient and maintaining a lower blind cavity pressure. Under the condition of variable injection coefficient (fixed secondary mass flow rate), for every 0.05 increase in the area contraction ratio of the mixing chamber, the primary mass flow rate needs to be increased by approximately 0.3 kg/s to reach the critical start-up state. The overall injection performance of the supersonic injector reaches its highest when it is at the critical start-up state. In terms of blind cavity extraction capability, the single-stage supersonic center injector is significantly superior to other types of injectors, with a minimum of 1.3 kPa achievable.

In development of high-energy chemical laser, the research of diffuser pressure recovery has important engineering application value. In this paper, the diffuser of DF chemical laser is studied by numerical simulation and experiment. The effects of diffuser divergence angle and secondary-throat on diffuser performance are calculated, analyzed and verified by experiments. The results show that the diffuser with 8° divergence angle has weak ability to resist back pressure, and reducing the divergence angle to 5° can effectively improve the ability to resist back pressure. The further optimized supersonic diffuser with secondary-throat can increase the recovery pressure of the diffuser again, reduce the energy loss of the air flow and improve the anti-back pressure characterisitics. At the same time, experimental verification is carried out for different models of diffusers, and the result is consistent with the trend of numerical simulation results.

In the process of high energy and high power extreme ultraviolet (EUV) irradiation, carbon deposition and surface oxidation are easy to form on the surface of the EUV mirror, which will affect its reflectivity and shorten its service life. To solve this problem, technology of nitride and oxide capping coating on the surface of extreme ultraviolet multilayer film was studied experimentally and characterized. In the preparation process, based on DC reactive magnetron sputtering coating technology, the “hyperbola” relationship between process gas flow and sputtering voltage was studied, to optimize the control of the amount of reactive gas, and then reduce the influence of reactive gas on Mo/Si multilayer films during reactive sputtering. Based on this method, TiN, ZrN and TiO2 capping layer were plated on the surface of Mo/Si multilayer films and were characterized by grazing incident X-ray reflection (GIXR), X-ray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM). It is proved that the nitride capping layer has certain performance advantages.

This paper introduces the overall layout of the Free Electron Laser & High Magnetic Field device under construction at Anhui University, and analyzes in detail the design requirements and difficulties in development of the water-cooling system for stable operation of the device, and presents the design of the water-cooling system for the whole device. The water-cooling system contains two independent water-cooling unit systems, with the design temperatures of (42±0.1)℃ and (25±0.5)℃ respectively, which can be adjusted within a certain range. The device water-cooling control system is developed based on EPICS (Experimental Physics and Industrial Control System) framework, the temperature regulation control function is realized by PLC (Programmable Logic Controller) program, and the PID (Proportion Integration Differentiation) parameter configuration is realized by PID regulator. The software development of the control system is mainly to realize the setting of the device parameters and the reading back of the status data under the EPICS environment, and to store the historical data into the Archiver Appliances database. The temperature control accuracy of the water-cooling control system during the trial operation reaches (42±0.03)℃ and (25±0.08)℃, which is in line with the design requirements, and the system is stable and reliable during the operation, which can well guarantee the safe and stable operation of the device.

The system-level cable coupling characteristics of UAVs are of great significance for the analysis of electromagnetic effects and mechanisms of UAVs. A field-circuit co-simulation model for electromagnetic interference of the multi-typed cables in UAVs is established and the coupling characteristics of the cables are analyzed. Moreover, considering the complex physical structure of the UAVs, studies on the system level cable coupling characteristics of the UAVs are carried out. Based on the surface current distribution of the UAV system, voltage monitoring points are set up at the UAV flight control port cables, wing cables, and rotor cables to monitor the voltage distribution of the UAV system cables, thus the weak links of the UAV system cable coupling are obtained. The simulation results show that when the plane wave is incident into the same length of cable at different angles, the coupling peak voltage is the largest when the electric field vector is parallel to the direction of the cable, and the coupling sensitive frequency point of different types of cables is the same; when the plane wave incident into different lengths of cable at the same angle, the reciprocals of the resonant frequency points satisfy the same multiple relationship as the cable lengths. In the actual UAV system cable irradiation scenario, the sensitive frequency band of flight control cable coupling is 300-600 MHz. The sensitive frequency band of the coupling of the UAV wing cable and the rotor cable is 300-430 MHz, and the peak voltage of the coupling of the flight control cable is significantly greater than that of the wing cable and the rotor cable.

High power microwave is easy to enter the system through the main coupling path of interconnection cables between electronic devices, disrupting or even damaging sensitive circuits or devices. To guide the rational wiring in engineering and improve the survival ability of electronic system under high power microwave, the coupling effect between HPM and cable under different parameters (cable length, height from ground, terminal load resistance, radiation field incidence angle) is systematically studied by combining simulation analysis and test verification. The coupling response law is obtained and the internal reasons are analyzed. The results show that with the increase of cable length, the coupling signal oscillates first and then tends to be stable gradually, and the oscillation period is equal to the wavelength of the incident wave. The coupling signal oscillates with the change of the height from the cable to the ground, and the maximum and minimum values appear when the height from the ground is odd times of 1/4 wavelength and integer times of 1/2 wavelength of the incident wave respectively. The coupling signal decreases first and then increases with the increase of terminal load resistance. When the load resistance matches the cable characteristic impedance, the coupling signal is the smallest. The coupling signal increases with the increase of the angle between the incoming wave direction and the cable layout direction, and the coupling signal is the largest when the two are perpendicular. On this basis, some optimization suggestions of cable laying in practical engineering are given, which provides guidance for system-level electromagnetic compatibility and high-power microwave protection design.

To assess the susceptibility of road vehicles in complex electromagnetic environments, this paper proposes a radiation immunity testing method of vehicles based on actual electromagnetic environments in reverberation chambers (RCs), which records the actual electromagnetic signals, constructs a complex signal playback system in an RC, and gives the cumulative distribution function (CDF) of the received power. Moreover, this paper provides a field strength calibration method and the radiation immunity testing in an RC. The radiation immunity testing of vehicle was conducted, and the results show that in the complex RC electromagnetic environment, some vehicles have electromagnetic safety risks. The study method provides important support for enterprises to evaluate the electromagnetic compatibility quality of vehicles.

To solve the problem of hard connection in waveguide transmission line, some waveguide components will use flexible waveguide, but the use of flexible waveguide will bring about the increase of transmission line loss. Aiming to investigate its loss and electrical heating under real operating conditions, we built a test platform based on a resonant ring with a 13.4 dB power gain in the traveling wave of the resonant ring, which successfully achieves an equivalent power of 140 kW at the position of the antinode by means of two 2 kW power amplifiers. Based on the results of simulations and experiments, we optimized the design of the rectangular flexible waveguide and improved its structure and materials to better cope with the thermal deformation and stress under high power input. The optimized flexible waveguide's electrical and thermal performance is better than that of similar foreign products.

The matching theory based on an equivalent circuit model is outlined that self-consistently determines the modulation of a klystron output cavity for arbitrary coupling of the output waveguide to the cavity and arbitrary cavity and/or electron beam parameters. An equivalent circuit model including a mutual inductance and the induced current for the output cavity is established, the output power and the reflected power are discussed. For the cases where the complex coupling coefficient equals 1 and does not equal 1, we respectively determined expressions for the reflected power. We derived an expression for the output power corresponding to the gap voltage for the case when the coupling is perfectly matched to the output waveguide, and also for the case of arbitrary coupling. We worked out expressions for the resonant frequency of the output cavity and externally-loaded Q leading to the matching conditions. If the matching conditions are satisfied, the output power corresponding to the new theory equals approximately the output power corresponding to the traditional theory.

Many applications including plasma excitation and high-power microwave sources require miniaturized high-voltage pulse generators. A miniaturized Marx generator with a novel magnetic isolated drive circuit is proposed. Making the source terminals of the charging MOSFET and discharging MOSFET in adjacent stages shorted in Marx generators based on half-bridge circuits, we apply a bipolar signal to both gates of these two MOSFETs and control both their switching. Combined with magnetic isolated driver with primary windings in series, only one bipolar signal from the primary side can synchronously drive all switches in the Marx generator, which considerably reduces the number of required components in the drive circuits. A 14-level experimental prototype was built, with a total weight of only 314 g, a width of 15 cm, a length of 8 cm, and a height of 5 cm. High-voltage square wave pulses with a peak voltage of 10 kV, a repetition frequency of 10 kHz, and a pulse width ranging from 200 ns to 5 μs were obtained over a resistive load. The 500 ns, 10 kV, and 1 kHz square wave pulses generated by the prototype were used to drive the dielectric barrier discharge load, and a uniform and strong discharge was generated, indicating that the miniaturized Marx generator is suitable for driving the dielectric barrier discharge load and being used as a low-temperature plasma source.

Aiming at the pulse operating characteristics of voltage-controlled thyristors, a cascadable driving circuit is designed to realize the synchronous opening of multi-stage series-connected voltage-controlled thyristors. Firstly, the circuit topology and working principle is analysed. in which the coupled inductor is used to isolate the driver signal and transfer power to open the switch. Based on Blumlein PFN, an experimental test circuit is built, in which a 6-stage MOS-controlled thyristor is series connected to be the discharge switch. A quasi-square-wave pulse current with an amplitude of 1.958 kA is obtained on a 4 Ω resistor.

Fast Burst Reactors (FBRs) are important subjects for criticality safety analysis research. They are characterized by irregular geometry, strong transient processes, tight multi-physics coupling, and complex feedback characteristics. This paper introduces an OpenFOAM based multi-physics nuclear criticality safety analysis code named INSL-UniFoam. It integrates discrete ordinate neutron transport solver, heat transfer and stress-strain solvers to detailly model the prompt super-critical burst pulse of FBRs. The UniFoam is first verified in the Godiva-I benchmark under both the steady-state condition and several transient scenarios. The results demonstrate that the program aligns well with the reference solution in terms of Keff calculation, peak power, and fission yield. Furthermore, it is capable of comprehensively outputting the distributions of power, temperature, and stress-strain throughout the pulse process.

The construction of the burnup lib determines the accuracy of burnup and decay heat calculations. The evaluation of burnup information in the nuclear lib is complex, leading to a large, rigid, and inefficient burnup matrix. This paper begins with the basic composition of the burnup lib, considering the impact of each nuclide and its transformation relationships on the accuracy of neutronics calculations and target nuclide nuclear density calculations, which serves as the basis for the compression of the burnup lib. To address the decay heat calculation accuracy loss caused by the compression of fission products, a nonlinear least squares optimization algorithm is used to fit the decay heat release function, and pseudo-decay nuclides are constructed to replace the fission product decay heat calculation, thereby maintaining the accuracy of decay heat calculations. Verification results show that the original detailed burnup lib contains more than 1 500 nuclides, which are reduced to fewer than 200 nuclides after compression. The compressed burnup lib does not introduce significant deviations in the calculation of the effective multiplication factor and nuclear density. In terms of decay heat calculations, the pseudo-decay nuclides significantly restore the decay heat calculation accuracy, with the contribution of decay heat to total power having a calculation deviation of less than 0.5%, meeting the required accuracy for decay heat calculations.

Double energy accelerator used in custom security monitoring is powered by the high-power magnetron, the top of pulse current waveform through the magnetron varies greatly in the double energy operation mode of the ordinary solid-state modulator due to nonlinear impedance of the magnetron, thus it is difficult to precisely distinguish contraband from the commodity in the cargo. To make the top of the pulse current waveform through the magnetron used in the double energy accelerator flat in the double energy operation mode, we developed a solid state modulator based on dual-loop parallel circuit topology, parallel IGBT solid state switch, high ratio pulse transformer technology and waveform correction technique for double energy accelerator. When the operating current through the magnetron is in the range of 70～120 A , this solid state modulator can output quasi-trapezoid current waveform in the double energy operation mode, and the relative top fluctuation of the pulse waveforms through the magnetron is less than 5%.

This paper presents a model for aerosol inertial collision removal under mixed gas jet conditions with high Weber number, based on the hydrodynamic model of jet penetration length and entrained droplet fraction. An analysis code of the aerosol pool scrubbing is constructed by spatial discretization of the injection zone. The experimental cases are adopted to validate the model, including two cases of 64% steam fraction, 0.7 m submergence depth, and mass fluxes of 217 kg/(m2·s) and 120 kg/(m2·s), conducted by small scale aerosol pool scrubbing facility, and one Reinforced Concerted Action 2 (RCA2) experiment with non-condensable gas-carrying aerosols at 0.5 m submergence depth and mass fluxes of 95 kg/(m2·s). The results show that the predictions of the model considering the jet hydrodynamic characteristics are in good agreement with the experimental values. Parameter analysis shows that as the Weber number of immersed jet increases, both jet penetration length and entrained droplet fraction increase, thereby enhancing the inertial collision between aerosols and droplets.