In recent years, the demand for high power density power supplies for accelerator systems has been growing rapidly, and the design of high-power modular power supplies is facing serious challenges [1–3]. The EMC design of high power density switching power supplies faces the serious challenge of accurate prediction and suppression of high-frequency conducted disturbances. In this paper, we propose an analysis method that incorporates circuit behavior modeling in concert with electromagnetic interference (EMI) spectral algorithms. Firstly, a cross-domain correlation model between time-domain current waveforms and frequency-domain interference features is established, and the switching transient process is mapped to the conduction path via parasitic parameters through circuit behavior modeling to improve the EMI prediction accuracy in the 150 kHz–30 MHz band. Second, the RBW adaptive FFT algorithm is used, and the EMI curves are compared with the simulation curves, and the experiments show that the method can accurately identify the EMI spectrum, and the spike bands are matched. This study provides a theoretical framework and a practical tool for the EMC design of high-density power modules.

A compact, modular kicker power supply based on a Blumlein-type pulse forming network (PFN) has been successfully developed for the Heavy Ion Accelerator Facility (HIAF) Booster Ring (BRing) fast extraction system. The system delivers a 5 kA rectangular current pulse to the kicker magnet with a rise time <650 ns, a flat-top duration >1 μs, and exceptional flat-top stability better than ±1

The High-energy Fragment Separator (HFRS) at the High-Intensity Heavy-Ion Accelerator Facility (HIAF) employs 11 superferric superconducting dipole magnets to deflect heavy-ion beams. Operating at a design current of 210 A and storing 370 kJ of magnetic energy, each magnet requires a dedicated DC power supply capable of providing highly stable excitation current and fast quench protection. This paper presents a complete power supply system for these magnets, with particular emphasis on a modular quench protection module (QPM) and an FPGA-based centralized controller. The QPM adopts a redundant full-bridge IGBT architecture in a compact 4U form factor. Upon receiving magnet quench trigger signals via a fiber optic interface, it completes IGBT turn-off and energy extraction circuit engagement within a microsecond-scale response time, thereby enabling fast and reliable magnet protection. The FPGA master controller incorporates a masking communication mechanism, which provides centralized management, independent control, and real-time diagnosis of magnet quench and module faults for distributed power units. Through a serial device server, the centralized controller simultaneously monitors the operating status and configures parameters for up to six power supply units over RS-485 links. Experimental results confirm that the power supply achieves a current stability of ±1 × 10−4. Under simulated magnet quench conditions, the protection system successfully transfers the stored energy to an external dump resistor, validating the reliability and effectiveness of the proposed scheme. The system provides a scalable protection solution for the HFRS superconducting dipole magnet array.

In high-power precision power supply applications such as particle accelerator magnet power supplies, stringent requirements are imposed on output voltage ripple coefficients better than 1×10−4. This paper focuses on suppressing the low-frequency output voltage ripple (below 300Hz). Conventional linear power supplies suffer from low efficiency, passive filtering demands excessively large capacitance, and single-stage active power decoupling (APD) is limited by the ripple current rating of the decoupling capacitor, making all of them inadequate for achieving the target level of ripple suppression. To address this, a multi-stage active power decoupling topology and its control method are proposed, designed to reduce the output voltage ripple coefficient from 1.5×10−1 to 5×10−4. The proposed method employs two independent APD circuits connected in cascade: the front stage provides preliminary attenuation of the majority of the low-frequency ripple power, while the rear stage achieves deep suppression of the residual ripple. A linear active disturbance rejection control (LADRC) strategy is incorporated to enhance system robustness. Experimental results on a 400W prototype demonstrate that the proposed method reduces the output voltage ripple coefficient from 1.5×10−1 (without APD) to 3.5×10−4, achieving a ripple suppression of −52dB (attenuation ratio of 7/3000). Under the same attenuation ratio, compared with a passive LC filter requiring 300mF of capacitance, the proposed method utilizes only 2mF of capacitance. Moreover, output stability comparable to that of a linear power supply is attained without the use of a linear pass transistor, thereby validating the effectiveness of the multi-stage APD configuration in surpassing the performance limitations of single-stage topologies.

One of the primary factors to overcome the operational limitations of the next generation of high-intensity heavy ion accelerators is to achieve a high-power, fast rise-rate, wide flat-top, lower droop, and pulsewidth adjustable bipolar kicker power supply. This article proposes a bipolar kicker power supply circuit topology with a Marx generator based on pulse forming network (PFN) for this application. In this topology, the Marx generator uses insulated gate bipolar transistors (IGBTs) as switches, which not only have the function of turning high-power energy on and off but also have the advantage of being able to adjust the pulsewidth compared to traditional thyratrons. Replacing the capacitor in Marx with PFN can improve the pulse flat-top stability and reduce the top droop. Structural analysis and simulation results prove the feasibility of the topology as mentioned above. The equivalent circuit of the Marx-PFN output pulse rising edge is calculated and simulated. The possibility of optimizing the output pulse waveform by adjusting the PFN segment impedance is analyzed. The Marx-PFN is highly modular in structure design, which greatly enhances the reliability and scalability of the power supply. The experimental results demonstrate that the developed power supply is capable of generating a bipolar current output ranging from 0 to +/- 5000 A, with an adjustable flat-top duration spanning 0- 2 mu s. The flatness (0- 1.5 mu s) was also confirmed to be in an acceptable value of less than +/- 1%. The performance of the prototype meets the design requirements, verifying the feasibility of the design scheme.

In digital control systems, many studies have been conducted to reduce control delay, thereby enhancing system bandwidth and stability margins. Most of these studies have used ADC with parallel interface or processor-integrated ADC, often overlooking the impact of ADC data transmission delays. In practical power applications, the use of external high-precision ADC with serial interface is more prevalent, and their data transmission delay can be the most time-consuming part of control. This paper presents a novel method suitable for digital controllers using serial interface ADCs, leveraging FPGA to perform real-time PWM modulation wave updates using the most significant bits (MSBs) during ADC data transmission. This approach also compensates for precision loss in a timely manner, thus reducing digital delay and improving current control without sacrificing accuracy.

A rectangular, high current pulsed power supply based on pulse forming networks (PFNs) and insulated gate bipolar transistors (IGBTs) has been developed for the new generation of high intensity heavy ion accelerator. It employs eight IGBTs as discharge switches in a connection of four in series and two in parallel to achieve high voltage and high current. The synchronous triggering of IGBTs is achieved by adjusting the delay time of optical signals. The test results show that it can generate a rectangular pulse current of 5 kA with a flat-top duration of 2.3 µs and a flat-top ripple of less than ±1

In order to meet the high precision requirement of the beam of the High Intensity Heavy Ion Accelerator Facility (HIAF) project at the Institute of Modern Physics (IMP), Chinese Academy of Sciences, a new method of improving the PWM (pulse width modulation) precision of the magnet power supplies, which uses the dynamic phase shift of the phase locked loop (PLL), has been employed. The wave measurement results which are obtained by adopting the new method demonstrate that the adjustment precision of the PWM is picosecond, while the accuracy is nanosecond obtained by using the existing common methods. The new method has laid a solid foundation for improving the beam accuracy of the HIAF project. Details of the new method will be presented in the paper.

The laminated busbar is a very critical component of the accelerator power supply equipment. A large number of large-capacity capacitors, high-power switching tubes and other important components are connected in parallel to it. It works in medium to high frequency and high current pulse mode. The performance of the laminated busbar—especially whether the distribution of inductance and resistance is uniform enough—has a direct impact on the reliable and stable operation of the power supply. In actual engineering practice, it is difficult to evaluate and judge the performance of laminated busbars simply and intuitively. It usually needs to be determined through actual testing after the power supply is manufactured. At this time, if it cannot meet the standards, it will have to be reworked. The process of optimizing the design is therefore time-consuming and laborious. This paper tests the use of finite element analysis method to analyze the inductance and resistance of laminated busbars with a specific structure. To achieve this goal, the script function of the existing commonly used commercial software ANSYS was re-developed to complete the script generator, which in disguise realized the multi-parameter batch scanning analysis and calculation functions required for research. On this basis, the inductor and resistance of a laminated busbar used in actual power supplies were analyzed and calculated, and a design method was proposed to make the distribution of the inductor and resistance more uniform by drilling holes in the laminated busbar metal plate, with good results. It also shows that it is feasible to introduce finite element analysis method into power supply design to analyze the performance of some special components, thereby improving the efficiency of design work.

The briefing proposes an on-chip system based on the RISC-V instruction set architecture (ISA) for application in accelerator power controllers to address some of the current shortcomings. The processor core adopts a three-stage pipeline design, supports the RV32IM instruction set, and features a custom bus structure. The system is equipped with ROM, RAM, and serial port control modules, along with a debugging module that supports online debugging of the processor core. The implemented instructions have passed the instruction set testing program provided by the RISC-V Foundation. The processor core has been implemented and verified on Xilinx XC7A100T FPGA, with resource requirements of 3134 LUTs and 865 FFs. Additionally, Coremark testing conducted on the processor core yielded a score of 2.44 Coremark/MHz, reaching the level of performance of an ARM Cortex-M0 processor. This meets the performance requirements of the current power controller. The system has been ported to the digital power controller at the Institute of Modern Physics, Chinese Academy of Sciences, achieving successful communication between the controller and host computer. In addition, the core can parse communication protocols.

Most magnet power supplies of Lanzhou heavy ion accelerators cooling storage ring are switch mode power supplies, operating in the mode of high pulsed current and high-precision. There are a large number of capacitors with various levels. The reliable operation of capacitors is very crucial for the reliability and stability of power supply. Based on the impedance frequency characteristics of capacitor and the FFT algorithm, this study extracts capacitor voltage and current at specific frequencies, enabling online monitoring of ESR and capacitance values. A 400 V, 10000 μF electrolytic capacitor is taken as an example to evaluate the ESR on different current conditions, and the ESR parameter of the capacitor is measured by an LCR meter. The error between the monitoring results and the measurement results is within 5

Capacitors are widely used in pulsed magnet power supplies to reduce ripple voltage,store energy,and decrease power vari-ation.In this study,DC-link capacitors in pulsed power supplies were investigated.By deriving an analytical method for the capacitor current on the H-bridge topology side,the root-mean-square value of the capacitor current was calculated,which helps in selecting the DC-link capacitors.The proposed method solves this problem quickly and with high accuracy.The current reconstruction of the DC-link capacitor is proposed to avoid structural damage in the capacitor's current measure-ment,and the capacitor's hotspot temperature and temperature rise are calculated using the FFT transform.The test results showed that the error between the calculated and measured temperature increases was within 1.5 ℃.Finally,the lifetime of DC-link capacitors was predicted based on Monte Carlo analysis.The proposed method can evaluate the reliability of DC-link capacitors in a non-isolated switching pulsed power supply for accelerators and is also applicable to film capacitors.

We describe a new modular cascaded H-bridge high power accelerator dipole magnet pulse power supply for the Heavy Ion Research Facility in Lanzhou-Cooler-Storage-Ring main ring (HIRFL-CSRm). The power supply consists of two branches connected in parallel, each of which consists of four 360 V/1800-A power units connected in series. Each power unit uses modular high power density voltage sources in parallel for the ac/dc converter and cascaded H-bridges for the dc/dc converter. In addition, digital control strategies are implemented. The voltage source modules adopt voltage and current dual closed-loop control, and the cascaded H-bridges use current dual closed-loop control with frequency-doubling modulation and cascaded multilevel control. The effectiveness of the proposed topology scheme and control strategies is confirmed through experiments, and the thermal stability of the power supply is verified through 72-h continuous output experiments.

In recent years,heavy ion accelerator technology has been rapidly developing worldwide and widely applied in the fields of space radiation simulation and particle ther-apy.Usually,a very high uniformity in the irradiation area is required for the extracted ion beams,which is crucial because it directly affects the experimental precision and therapeutic effect.Specifically,ultra-large-area and high-uniformity scanning are crucial requirements for spacecraft radiation effects assessment and serve as core specification for beamline terminal design.In the 300 MeV proton and heavy ion accelerator complex at the Space Environment Simulation and Research Infrastructure(SESRI),proton and heavy ion beams will be accelerated and ultimately delivered to three irradiation termi-nals.In order to achieve the required large irradiation area of 320 mm× 320 mm,hori-zontal and vertical scanning magnets are used in the extraction beam line.However,considering the various requirements for beam species and energies,the tracking accura-cy of power supplies(PSs),the eddy current effect of scanning magnets,and the fluctu-ation of ion bunch structure will reduce the irradiation uniformity.To mitigate these effects,a beam uniformity optimization method based on the measured beam distribution was proposed and applied in the accelerator complex at SESRI.In the experiment,the uniformity is successfully optimized from 75％to over 90％after five iterations of adjustment to the PS waveforms.In this paper,the method and experimental results were introduced.

Object detection models represented by YOLO series have been widely used and have achieved great results on the high quality datasets, but not all the working conditions are ideal. To settle down the problem of locating targets on low quality datasets, the existing methods either train a new object detection network, or need a large collection of low-quality datasets to train. However, we propose a framework in this paper and apply it on the YOLO models called DiffYOLO. Specifically, we extract feature maps from the denoising diffusion probabilistic models to enhance the well-trained models, which allows us fine-tune YOLO on high-quality datasets and test on low-quality datasets. The results proved this framework can not only prove the performance on noisy datasets, but also prove the detection results on high-quality test datasets. We will supplement more experiments later (with various datasets and network architectures).

Anomaly Detection on IoT devices is a widely studied task in industry. As deep learning methods developed, they have been a prevailing solution to this task, especially in the certain working condition of lacking anomaly samples. Among all the methods, for complicated data with changing period and transmitting noise in the real production environments, VAE appears to be potential. We first reconstruct the 1D time series to 2D tensors as it is hard to apply normal data augmentation methods on a time series dataset with continuous semantic. Then we used a CNN-VAE model, an improved reconstruction-based anomaly detection method, to compute the reconstruction error in an unsupervised way. The method can be integrated to an end-to-end framework as it is lightweight. Comparing with other anomaly detection methods on our dataset, our method showed the best results.

应用于强流重离子加速器装置增强环(HIAF-BRing)的快循环全储能脉冲电源需要在极宽的输出电压范围内保持极高的控制精度,为此电源采用了高压功率单元和低压功率单元串联的拓扑方式,在低压段采用低压功率单元,电压升高之后切换到高压功率单元,通过高低压切换控制来实现电流全阶段的高精度输出.但是在样机实测中发现存在切换点的振荡问题,导致切换点处的输出电流绝对误差无法满足指标要求.本文提出了一种切换点平滑控制算法来平滑处理切换点占空比,给出了仿真结果,并且在HIAF-BRing快循环全储能脉冲电源样机上面实际验证了高低压切换控制方法及其切换点平滑控制算法的有效性.实验结果表明:100?A注入平台的输出电流绝对误差由±500?mA降至±50?mA,100?A注入平台的切换点处输出电流绝对误差由±1.16?A降至±120?mA,100?A注入平台输出精度较低的问题得以解决.

The BRing (Booster Ring) extraction kicker is one of the important devices to achieve fast extraction in the HIAF (High Intensity heavy ion Accelerator Facility). To meet the requirements of the BRing extraction kicker, the pulse power supply is required to provide rectangular current pulse. Thus, a new topology based on the BPFN (blumlein pulse forming network) circuit is applied to the pulse power supply in this study. The experimental results show that the extraction current is 5.1 kA. Besides, a flat-top length of 1.3 µs has been accomplished. The rise time is 500 ns and the flatness is less than ±1%. The output performance of the pulse power supply satisfies the design requirements and provides technical support and engineering experience for the kicker system of HIAF.

Stable magnetic field is crucial for the precision experiments conducted at the heavy ion storage rings. Besides the current stability of the power supply, the magnetic field is also influenced by varying ambient factors such as temperatures. This paper proposed a dual-loop hysteresis control method to passively change the output current of the power supply according to the magnetic field monitored by the nuclear magnetic resonance (NMR) probes. As a result, the long-term relative changes of magnetic field were reduced from dB/B approximate to 5.75 x 10-5 to 2.3 x 10-5 within three days.

The experimental Cooler Storage Ring (CSRe) of the Heavy Ion Research Facility in Lanzhou (HIRFL) is an experimental platform for nuclear mass measurement. The particle beam required for the experiment moves in a vacuum tube under the constraint of a magnetic field. The magnet power supply provides excitation current to the magnet load. The current stability of the accelerator power supply is directly related to the magnetic field. In particular, improving the stability of the magnetic field of the dipolar magnet is of great significance for obtaining good beam quality and better carrying out physical experiments. In order to obtain a better magnetic field environment, this paper built a measuring system for the experimental ring diode magnet power supply, analyzed the current, cooling water temperature and other key factors affecting the output current, and proposed a hysteresis control method to further improve the stability of the power supply. By improving the existing power supply of the bipolar magnet, the stability of the output current is improved from 50ppm to 26ppm for a long term.