分类： 物理学 >> 核物理学 提交时间： 2025-07-08
Zhu, Mr. Jun-Yu
Li , Dr. Xiao
Yu, Ms. Jiebing
Lu, Dr. Zhijun
Hao, Dr. XueRui
Wu, Dr. Bin
Zhang, Mr. Ling Chun
Long, Mr. Wei
Liu, Mr. Yang
Chen, Mr. Shengyi
Wu, Dr. Jian
Li, Dr. Xiang
摘要： Double radio-frequency (RF) systems, comprising both fundamental and harmonic cavities, are essential in advanced synchrotron light sources for lengthening beam bunches, thereby increasing the Touschek lifetime and reducing intrabeam scattering. RF cavities must incorporate effective higher-order mode (HOM) damping to mitigate coupled bunch instabilities (CBI). Additionally, a compact design is crucial for fitting within the limited straight sections of storage rings. This paper presents a novel coaxial bimodal cavity that simultaneously delivers fundamental and harmonic voltages, allowing independent operation of both modes and effective HOM damping. It offers a more compact and efficient alternative to conventional separate cavities. A prototype cavity design was developed, featuring resonant frequencies of 166.6 MHz for the fundamental mode and 499.8 MHz for the third harmonic mode. Simulation results indicate the successful implementation of a bimodal RF cavity, featuring independent frequency tuning, separate RF drives, and effective HOM damping. This work offers a compact and efficient solution for implementing double-frequency RF systems in advanced synchrotron light sources.
分类： 物理学 >> 核物理学 提交时间： 2025-06-13
Hao, Dr. XueRui
Li , Dr. Xiao
Zhu, Mr. Jun-Yu
Wu, Dr. Bin
Chen, Mr. Shengyi
Liu, Mr. Yang
Zhang, Mr. Ling Chun
Long, Mr. Wei
Liu, Dr. Hua Sheng
摘要： The TM020 mode damped cavity enables compact accelerators but suffers from severe electromagnetic field leak- age due to coupling-slot misalignment and structural asymmetry. We propose an integrated narrowband filter based on RLC circuit design to selectively suppress TM020 leakage while preserving higher-order modes damping. Crucially, the filter reduces electromagnetic field leakage to below 0.6%—over an order of magnitude lower than unfiltered cav- ities (>4%)—and enhances fourfold increase in positional tolerance (± 0.8 mm vs. ± 0.2 mm). Impedance spectra confirm minimal impact on higher-order modes damping. Under 20-kW power, thermo-mechanical analysis shows exceptional stability: peak temperature rise ≤21.3 K, frequency detuning ≤0.182 MHz, and leakage increase to only 0.65% (still 6 times lower than unfiltered baselines). This design resolves the critical leakage-robustness trade-off in next-generation synchrotrons.
分类： 物理学 >> 核物理学 提交时间： 2025-06-04
Zuo, Dr. Taisen
Lu, Mr. Zhanjiang
Zhu, Mr. Hong
Han, Dr. Zehua
Deng, Mr. Changdong
He, Dr. Yongcheng
Tian, Dr. Long
Wang, Prof. Tianhao 王天昊
Xiao, Mr. Songwen
Zhenqiang, Mr. He
Lin, Mr. Xiong
Ma, Dr. Changli
Cheng, Dr. He
摘要： The focusing of pulsed neutrons can increase neutron flux, reduce sample volume, and enable access to smaller scattering angles. Consequently, it represents a critical challenge for next-generation spallation neutron sources. The primary difficulty stems from the inherent chromatic aberration of white neutrons. Here, a new compact Nested Rotating Sextupole Permanent Magnet (Nest-Rotating-SPM) lens, with a total length of 200 mm, was developed and tested at the Very Small Angle Neutron Scattering (VSANS) instrument at the China Spallation Neutron Source (CSNS). Through synchronization of the outer sextupole lens rotation with the neutron pulse from the source, we achieved aberration-free focusing of neutrons with wavelengths between 11.0 Å and 15.5 Å for the first time. The implementation of water cooling and carbon fiber winding ensures both magnetic field stability and mechanical robustness of the inner sextupole. The compact design incorporating bridge sextupoles enables Lego-like assembly of multiple lens units for focusing pulsed neutrons with wavelengths shorter than 10.0 Å, making it practically useful in a pulsed neutron instrument to enhance neutron flux or access lower scattering vectors. Additional research is required to mitigate background noise.
分类： 物理学 >> 核物理学 提交时间： 2025-05-30
Zeng, Mr. Yujie
Song, Ms. Tianzi
Wang, Mr. Xuesen
Zhang, Prof. Yumei
Lin, Dr. Tao
You, Prof. Zhengyun
摘要： In high-energy physics~(HEP) experiments, visualization software plays a pivotal role in detector design, offline software development, and event data analysis. The visualization tools integrate detailed detector geometry with complex event data models, providing the researchers with invaluable insights into experimental results. Phoenix is an emerging general-purpose visualization platform for the current and next-generation HEP experiments. In this study, we develop an event display software based on Phoenix for the CEPC experiment. It offers necessary functionalities for visualizing detector geometries and displaying event data, allowing the researchers to optimize detector design, test simulation and reconstruction algorithms, and analyze event data in a visualized way. Additionally, we discuss the future applications of the event display software, including its usage in online monitoring and the potential to build virtual reality projects for enhanced data visualization.
分类： 物理学 >> 核物理学 提交时间： 2025-05-28
Miao, Mr. Dexing
Xu, Prof. Zijun
Xiang, Dr. Zhiyu
Liu, Dr. Pingcheng
Ambrosi, Prof. Giovanni
Barbanera, Dr. Mattia
Cai, Dr. Mengke
Cai, Prof. Xudong
Chou, Dr. Hsin-Yi
Duranti, Prof. Matteo
Formato, Dr. Valerio
Ionica, Dr. Maria
Jiang, Dr. Yaozu
Jin, Mr. LiangChengLong
Koutsenko, Dr. Vladimir
Li, Mr. Qinze
Liu, Mr. Cong
Lv, Mr. Xingjian
Oliva, Dr. Alberto
Peng, Wenxi
摘要： A silicon microstrip detector (SSD) has been developed to have state of the art spatial resolution and a large sensitive area under stringent power constraints. The design incorporates three floating strips with their bias resistors inserted between two aluminum readout strips. Beam test measurements with the single sensor confirmed that this configuration achieves a total detection efficiency of 99.8% and spatial resolution 7.6 μm for MIPs. A double-η algorithm was developed to optimize hit position reconstruction for this SSD. The design can be adapted for large area silicon detectors.
分类： 物理学 >> 核物理学 提交时间： 2025-05-27
Tian, Dr. Long
Gao, Dr. Han
Wang, Prof. Tianhao 王天昊
Teng, Mr. Haiyun
tang, Dr. jian
Zheng, Mr. Qingbo
Zuo, Dr. Taisen
Cui, Dr. Tengfei
Wang, Mr. Bin
xu, Mr. Qin
Qiu, Mr. Yongxiang
Dong, Mr. Yuchen 董雨晨
Zheng, Mr. Yujie
Qin, Dr. Zecong
Han, Dr. Zehua
Zhang, Dr. Junpei 张俊佩
Cheng, Dr. He
Tong, Prof. Xin 童欣
摘要： Polarization-analyzed small-angle neutron scattering (PASANS) is an advanced technique that enables the selective investigation of magnetic scattering phenomena in magnetic materials and distinguishing coherent scattering obscured by an incoherent background, making it particularly valuable for cutting-edge research. The successful implementation of PASANS in China was achieved for the first time at the newly commissioned Very Small Angle Neutron Scattering (VSANS) instrument at the China Spallation Neutron Source (CSNS). This technique employs a combination of a double-V cavity supermirror polarizer and a radio frequency (RF) neutron spin flipper to manipulate the polarization of the incident neutrons. The scattered neutron polarization is stably analyzed by a specially designed in-situ optical pumping 3He neutron spin filter, which covers a spatially symmetric scattering angle coverage of about 4.8○. A comprehensive PASANS data reduction method, aimed at pulsed neutron beams, has been established and validated with a silver behenate powder sample, achieving a maximum momentum transfer coverage of approximately 0.25 Å-1.
分类： 物理学 >> 核物理学 提交时间： 2025-05-23
Guo, Dr. Yuhang
Li, Dr. Qiang
bao, Dr. yu
Pan, Mr. Ziwen
Lv, Dr. You
Stewart, Dr. Rhea
Hillier, Prof. Adrian
Cottrell, Prof. Stephen
Baker, Prof. Peter
Lord, Prof. James
liu, Mr. lei
Liang, Prof. Zhijun
Li, Dr. Mengzhao
Zhao, Prof. Mei
Gaobo, Dr. Xu
Feng, Dr. Meichan
摘要： Muon Spin Rotation/Relaxation/Resonance (μSR) is a versatile and powerful non-destructive technology for investigating the magnetic properties of materials at the microscopic level. The μSR technique typically utilizes fully spin polarized beams of positive muons generated at particle accelerator facilities and measures the evolution of the muon spin polarization inside a sample to extract information about the local magnetic environment in materials. With the development of accelerator technologies, intensities of muon beams are being continuously improved, which will cause a pile-up problem to the μSR spectrometer. This problem is becoming especially challenging at intense pulsed muon sources since the instantaneous data rates are expected to be much higher. The first muon source in China, named MELODY, is currently under construction and will be a pulsed source of muons operated at a repetition frequency of only 1 Hz due to limitations of the accelerator system at CSNS. Consequently, there is a strong motivation to operate MELODY at significantly higher muon intensities. This necessitates an upgrade of the detector system inside the spectrometer, which should be smaller and faster to accommodate the increased intensity per pulse of muons. The Low Gain Avalanche Diode (LGAD), characterized by a typical pulse width of 2 ns and a segmentation size in the centimeters range, has the potential to significantly improve the counting rates of μSR spectrometers that utilize a high intensity pulsed muon source. Thus, it is expected that the LGAD detector is a promising candidate to enhance the performance of μSR spectrometers at the new MELODY muon source. To validate this, tests on the LGAD were conducted at the ISIS pulsed muon source at the Rutherford Appleton Laboratory, UK. This paper will describe the setup of the candidate LGAD devices and the subsequent analysis of the experiment data.
分类： 物理学 >> 核物理学 提交时间： 2025-05-08
摘要： In the BESIII detector at Beijing electron-positron collider, billions of events from e+e− collisions are recorded. These events passing through the trigger system are saved in raw data format files. They play an important role in the study of physics at τ -charm energy region. Here, we publish an e+e− collision dataset containing both Monte Carlo simulation samples and real data collected by the BESIII detector. The data passes through the detector trigger system, file format conversion, physics information extraction, and finally saves the physics information and detector response in text format files. This dataset is publicly available and is intended to provide interested scientists and those outside of the BESIII collaboration with event information from BE- SIII that can be used in understanding the physics research in e+e− collisions, developing visualization projects for physics education, public outreach, and science advocacy.
分类： 物理学 >> 核物理学 提交时间： 2025-04-30
Shi, Dr. Huangchao
Wang, Miss Danqi
Liu, Miss Meiqi
Yang, Yidong
Qi, Mr. Baohua
Liu, Dr. Yong
Qin, Mr. Yanghui
Feng, Dr. Changqing (Nuclear electronics)
Liu, Dr. Yi
Zhu, Dr. Hongbo
摘要： Proton Computed Tomography (pCT) provides a promising solution to enhance the accuracy of Relative Stopping Power (RSP) required for proton therapy planning. This research introduces a novel high-granularity pCT architecture that incorporates a silicon pixel tracking system and a calorimetric range telescope, which uniquely integrates range telescope functionality with track discrimination capabilities. The Bortfeld function fitting and Convolutional Neural Network (CNN) classifier algorithms are developed and applied for discrimination. In simulation studies, both approaches demonstrate the capability to reduce uncertainty in Water Equivalent Path Length (WEPL) determination for individual proton tracks to below 3 mm. The standard imaging protocol (3.2 mGy, 4×108 protons) achieves sub-millimeter spatial resolution (∼0.5 mm) with sub-1% RSP accuracy. With proton count requirements reduced by track discrimination, an ultra-low-dose protocol (0.16 mGy, 2×107 protons) is proposed with achieved sub-1% RSP accuracy and 1.1 mm spatial resolution in simulation. This low-dose performance significantly expands clinical applicability, particularly for pediatric imaging or frequent imaging scenarios. Furthermore, the target 10 MHz proton detection rate suggests potential for real-time image guidance during radiotherapy. By circumventing the need for ultra-precise energy measurements, this design minimizes hardware complexity and provides a scalable foundation for future pCT systems.
分类： 物理学 >> 核物理学 提交时间： 2025-04-28
Zhu, Mr. Jun-Yu
Li , Dr. Xiao
Yu, Ms. Jiebing
Lu, Dr. Zhijun
Hao, Dr. Xuerui
Wu, Dr. Bin
Zhang, Mr. Ling Chun
Long, Mr. Wei
Liu, Mr. Yang
Chen, Mr. Shengyi
Wu, Dr. Jian
Li, Dr. Xiang
摘要： Double radio-frequency (RF) systems, comprising both fundamental and harmonic cavities, are essential in advanced synchrotron light sources for lengthening beam bunches, thereby increasing the Touschek lifetime and reducing intrabeam scattering. RF cavities must incorporate effective higher-order mode (HOM) damping to mitigate coupled bunch instabilities (CBI). Additionally, a compact design is crucial for fitting within the limited straight sections of storage rings. This paper presents a novel coaxial bimodal cavity that simultaneously delivers fundamental and harmonic voltages, allowing independent operation of both modes and effective HOM damping. It offers a more compact and efficient alternative to conventional separate cavities. A prototype cavity design was developed, featuring resonant frequencies of 166.6 MHz for the fundamental mode and 499.8 MHz for the third harmonic mode. Simulation results indicate the successful implementation of a bimodal RF cavity, featuring independent frequency tuning, separate RF drives, and effective HOM damping. This work offers a compact and efficient solution for implementing double-frequency RF systems in advanced synchrotron light sources.
分类： 物理学 >> 核物理学 提交时间： 2025-04-17
Deng, Mr. Lin-Jin
Wang, Dr. Chen-Yang
Cheng, Dr. Hui
Xue, Mr. Ruihao
Cheng, Prof. Fa-Liang
Yuan, Dr. Bao
Bai, Mr. Bo
Sun, Dr. Yuan
Ye, Mr. Fan
Dou, Dr. Meng-Jia
Huang, Mr. Zhiqiang
Luo, Dr. Wan-ju
Hu, Dr. Hai-Tao
Tong, Dr. Xin
摘要： Metal foil element furnaces are widely used in neutron scattering sample environments. However, since the metal foil blocks the neutron beam, these furnaces typically have a large background from the metal foil. Therefore, we designed a special heating element with an innovative perforated structure for the furnace. This novel heating element can significantly reduce the instrumental background, and is specifically applicable to the Multi-Physics Instrument and High-Pressure Neutron Diffractometer in CSNS. This structure reduces material obstruction of the neutron beam, thereby greatly lowering the experimental background. Additionally, we performed electro-thermal-mechanical coupled finite element simulation on the heating element to analyze its temperature and stress distribution, and identified the locations most susceptible to failure. We adjusted the heating element's hole size to study temperature and stress changes, providing a theoretical basis for future optimization of the heating element. This furnace is extensively applied in CSNS, facilitating users in accomplishing neutron scattering experiments and achieving a series of research outcomes.
分类： 物理学 >> 核物理学 提交时间： 2025-04-10
Gu, Dr. Minhao
Xue, Ms. Jieming
Li, Dr. Yakang
cao, Dr. ping 曹平
Ren, Dr. Jie
Chen, Dr. Yonghao
Jiang, Dr. Wei
Yi, Dr. Han
Hu, Dr. Peng
Fan, Dr. Ruirui
摘要： This article introduces the methodologies and instrumentation for data measurement and propagation at the Back-n white neutron facility of the China Spallation Neutron Source (CSNS). The Back-n facility employs backscattering techniques to generate a broad spectrum of white neutrons. Equipped with advanced detectors such as the Light Particle Detector Array (LPDA) and the Fission Ionization Chamber Detector (FIXM), the facility achieves high-precision data acquisition through a general-purpose electronics system. Data are managed and stored in a hierarchical system supported by the National High Energy Physics Science Data Center (NHEPDC), ensuring long-term preservation and efficient access. The data from Back-n experiments significantly contribute to nuclear physics, reactor design, astrophysics, and medical physics, enhancing the understanding of nuclear processes and supporting interdisciplinary research.
分类： 核科学技术 >> 核探测技术与核电子学 提交时间： 2025-04-06
摘要： In-situ exploration of deep-sea seabed resources is a valuable research direction. Neutron activation-based in-situ exploration methods for seabed polymetallic nodules or crust resources are theoretically feasible because of the high content and high neutron capture cross-section of manganese in these nodules or crusts. However, to date, only a few relevant studies have been conducted. In this study, a prototype Deep-sea In-situ Neutron Activation Spectrometer (DINAS) was designed for resource exploration. Through an analysis of the principles of the spectrometer combined with Monte Carlo simulations of the physical principles and finite element simulations of deep-sea pressure, the structure and fundamental components of the spectrometer were determined. The inner core of the spectrometer comprised three components: a compact neutron generator for neutron production, gamma-ray detectors, and an electronics system. The gamma-ray detector array of the spectrometer consisted of LaBr3 and BGO scintillation crystals coupled with silicon photomultiplier (SiPM) arrays. The electronics system was divided into two modules to implement the SiPM readout and digital signal analysis along the modular design lines. The experimental activation of neutron beamlines at the China Spallation Neutron Source demonstrated the capability of the spectrometer detectors to detect activated gamma rays and showed that the spectrometer achieved an energy resolution of 2.8 % at 847 keV for the LaBr3 detector and 6.7 % at 2.113 MeV for the BGO detector. The laboratory model experiment tested the functionality of the spectrometer prototype, whereas the Geant4 simulation verified the reliability of the Monte Carlo method. The method and prototype proposed in this study proved feasible for the in-situ detection of polymetallic nodules or crusts in deep-sea environments
分类： 物理学 >> 核物理学 提交时间： 2025-04-01
摘要： In the BESIII detector at Beijing electron-positron collider, billions of events from $e^{+}e^{-}$ collisions are recorded. These events passing through the trigger system are saved in raw data format files. They play an important role in the study of physics at $\tau$-charm energy region. Here, we introduce an $e^{+}e^{-}$ collision dataset containing both Monte Carlo simulation samples and real data collected by the BESIII detector, which passes through the detector trigger system, file format conversion, physics information extraction, and finally saves the physics information and detector response in text format files. This dataset is publicly available and is intended to provide interested scientists and those outside of the BESIII community with event information from BESIII that can be used in understanding the physics research in $e^{+}e^{-}$ collisions, developing visualization projects for physics education, public outreach, and science advocacy.
分类： 物理学 >> 核物理学 提交时间： 2025-02-27
Chen, Mr. Ji-Xin
Jixin, Mr. Chen
Bai, Dr. Bo 白波
Cheng, Prof. Fa-Liang
Sun, Dr. Yuan
Cheng, Dr. Hui
Yuan, Dr. Bao
Dou, Dr. Meng-Jia
Wang, Dr. Chen-Yang
Lin, Mr. Quan
Lu, Mr. Zi-Cong
Deng, Mr. Lin-Jin
Hu, Dr. Hai-Tao
Tong, Dr. Xin
摘要： The use of automatic sample exchange technology can greatly improve the efficiency of neutron scattering experiments. China spallation neutron source (CSNS) has currently developed a cryogenic sample changer that design for exchange sample in the temperature range of 100K to 300K and finally achieve the minimum operating temperature is 80K. Samples are provided with a temperature ranging from 4.2K to 800K by CCR-02 through a closed cycle refrigerator (CCR) and a heater. This paper introduces the structure of the sample changer, which can accommodate up to 24 samples and the replacement time of each sample does not exceed 2 minutes. CSNS II phase will develop a second generation sample changer with an operating temperature range from 10K to 350K. For this requirement, we researched why the chain drive jammed in 80K and redesigned the chain and the support. By simulating in Ansys Workbench, we concluded that the new chain has more excellent performance in low-temperature and its stress is small and uniform. Because of the stress concentration, the S chain plate with a clamping angle of 20°is selected. The new support under Fluent can get the lowest temperature is 4.48K (316 stainless steel) and 4.23K (titanium). The new design will be tested after processing is completed.
分类： 物理学 >> 核物理学 提交时间： 2025-02-24
Gu, Dr. Minhao
Xue, Ms. Jieming
Li, Dr. Yakang
cao, Dr. ping 曹平
Ren, Dr. Jie
Chen, Dr. Yonghao
Jiang, Dr. Wei
Yi, Dr. Han
Hu, Dr. Peng
Fan, Dr. Ruirui
摘要： This article introduces the methodologies and instrumentation for data measurement and propagation at the Back-n white neutron facility of the China Spallation Neutron Source (CSNS). The Back-n facility employs backscattering techniques to generate a broad spectrum of white neutrons, which are essential for precise measurements of neutron-induced reactions. Equipped with advanced detectors such as the Light Particle Detector Array (LPDA) and the Fission Ionization Chamber Detector (FIXM), the facility achieves high-precision data acquisition through a general-purpose electronics system. Data are managed and stored in a hierarchical system supported by the National High Energy Physics Science Data Center (NHEPDC), ensuring long-term preservation and efficient access. The data from Back-n experiments significantly contribute to nuclear physics, reactor design, astrophysics, and medical physics, enhancing the understanding of nuclear processes and supporting interdisciplinary research.
分类： 物理学 >> 核物理学 提交时间： 2025-02-24
摘要： Tellurium-130 is a promising candidate for neutrinoless double beta decay (0νββ) search due to its high natural abundance. However, it is challenging to dope tellurium into liquid scintillator at desired level while minimumly affecting the optical properties like light yield and transparency. Lots of R\&D work are needed to develop the optimized recipes, where quick and robust characterizations of samples are highly demanded. In this paper, we present an automated setup designed for the efficient and precise measurement of light yield in liquid scintillators. This setup can measure up to eight sets of samples in a measurement round. The systematic uncertainty is less than 2%. This setup is playing a crucial role in the optimization of liquid scintillator formulations.
分类： 物理学 >> 核物理学 提交时间： 2025-02-21
摘要： Tellurium-130 is a promising candidate for neutrinoless double beta decay (0νββ) search due to its high natural abundance. However, it is challenging to dope tellurium into liquid scintillator at desired level while minimumly affecting the optical properties like light yield and transparency. Lots of R\&D work are needed to develop the optimized recipes, where quick and robust characterizations of samples are highly demanded. In this paper, we present an automated setup designed for the efficient and precise measurement of light yield in liquid scintillators. This setup can measure up to eight sets of samples in a measurement round. The systematic uncertainty is less than 2\%. This setup is playing a crucial role in the optimization of liquid scintillator formulations.
分类： 物理学 >> 核物理学 提交时间： 2025-02-19
Huang, Dr. Liangsheng
Xu, Dr. Shou-Yan
Liu, Prof. Yuntao
Liu, Miss Yi-Qin
Chen, Dr. Jianliang
Deng, Mr. Changdong
Huang, Dr. Ming-Yang
Rao, Mr. Li
Liu, Dr. Hanyang
Qi, Dr. Xin
摘要： The Rapid Cycling Synchrotron (RCS) in the China Spallation Neutron Source (CSNS) operates as a high-intensity proton accelerator. The coupled bunch instability was observed during the RCS beam commissioning, which highly limits the beam power. To investigate the dynamics of instability under increased beam power, a pulsed octupole magnet with a gradient of 900T/m3 is developed. The magnet system integrates an octupole magnet with a pulsed power supply. The field is carefully measured to examine the performance before installation into the tunnel. After the installation of the magnets, beam measurements are performed to confirm the effectiveness of the instability mitigation on an actual proton beam. The measurement results show that the instability can be suppressed by using the pulsed octupole magnet, particularly at the high energy stage in an acceleration cycle, meeting the requirements for stable operation of the accelerator. Additionally, when the instability is completely suppressed through chromaticity optimization, octupole magnets can significantly enhance the RCS transmission efficiency, which is crucial for controlling beam loss. The pulsed octupole magnet offers significant progress of beam stability in the RCS, providing valuable experience for further beam power enhancement.
分类： 物理学 >> 核物理学 提交时间： 2025-02-15
Huang, Dr. Liangsheng
Wu, Dr. Bin
Huang, Dr. Ming-Yang
Liu, Dr. Ren-Hong
Tan, Mr. Biao
Wang, Dr. Pengcheng
Xiao, Mr. Yongchuan
Zeng, Mr. Li-rui
Li , Dr. Xiao
摘要： In a rapid cycling synchrotron (RCS), the magnetic field is synchronized with the beam energy, creating a highly dynamic magnetic environment. A ceramic chamber with a shielding layer (RF shield), composed of a series of copper strips connected a capacitor at either end, is typically employed as the vacuum chamber to mitigate eddy current effects and beam coupling impedance. Consequently, the ceramic chamber exhibits a thin-walled, multilayered complex structure. Previous theoretical studies suggest that the impedance of such a structure has a negligible impact on the beam. However, recent impedance measurements of the ceramic chamber in the China Spallation Neutron Source (CSNS) RCS reveal a resonance in low-frequency range, which further theoretical analysis confirms as a source of beam instability in the RCS. Currently, the magnitude of this impedance cannot be accurately assessed through theoretical calculations. In this study, we utilize CST Microwave Studio to confirm the impedance of the ceramic chamber. Further simulations covering six different types of ceramic chambers are conducted to develop an impedance model in the RCS. Additionally, this paper investigates the resonant characteristics of the ceramic chamber impedance, finding that the resonant frequency is closely related to the capacitance of capacitors. This finding provides clear directions for further impedance optimization and is crucial for achieving the beam power of 500 kW for the CSNS Phase II project (CSNS-II). However, careful attention must be given to the voltage across the capacitors.
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