分类： 物理学 >> 核物理学 提交时间： 2025-04-17
Zhou, Dr. Yimei
lai, Dr. longwei
Pan, Dr. Jialan
Yan, Prof. Yingbing 阎映炳
Chen, Dr. Jian
Liu, Dr. Xiaoqing
Cao, Dr. Shanshan
yuan, rx
摘要： Resonant cavity monitors are widely used in Free Electron Lasers (FELs) and proposed for linear collider for high-resolution position and phase measurements. The read-out electronics is a main limiting factor affecting system performance. A prototype cavity monitor system with direct RF sampling electronics was developed for C-band cavity beam arrival monitors used in SHINE, operating at the TM010 monopole mode frequency of 3.52GHz.The direct RF sampling electronics simplifies the otherwise complex RF front-end applying traditional down-conversion electronics. The direct RF sampling processor use ADCs with -3dB bandwidth of 9 GHz, a maximum sampling rate of 2.6 GSPS, and 8 bits ENOB at 3.52 GHz. A theoretical analysis demonstrates that the direct-digital down-conversion electronics achieves comparable performance to analog RF down-converters, with online beam tests at SXFEL confirming its high sensitivity. The relative amplitude error of the electronics is 1.3× 10^-4 at 80 pC, and the relative phase error is 8.4 fs. Even with a beam charge of 1 pC, the relative amplitude error of the electronics is better than 1.0× 10^-3, and the relative phase error is 47.7 fs. It paves the way for large-scale applications of direct RF sampling electronics in SHINE. This represents a significant advancement in beam instrumentation at SHINE, leading to both a reduction in project costs and an enhancement in system reliability.
分类： 物理学 >> 核物理学 提交时间： 2025-01-23
Zhou, Dr. Yimei
lai, Dr. longwei
Pan, Dr. Jialan
Yan, Prof. Yingbing 阎映炳
Chen, Dr. Jian
Liu, Dr. Xiaoqing
Cao, Dr. Shanshan
yuan, rx
摘要： Resonant cavity monitors are widely used in Free Electron Lasers (FELs) and proposed for linear collider for high-resolution position and phase measurements. The read-out electronics is a main limiting factor affecting system performance. A prototype cavity monitor system with direct RF sampling electronics was developed for the C-band cavity beam arrival monitors used in SHINE. The diopole-mode frequency of the cavity is 3.52 GHz. The direct RF sampling electronics simplifies the otherwise complex RF front-end applying traditional down-conversion electronics. The direct RF sampling processor use ADCs with -3dB bandwidth of 9 GHz, a maximum sampling rate of 2.6 GSPS, and 8 bits ENOB at 3.52 GHz. A theoretical analysis shows, that the direct-digital down-conversion electronics should have the same performance as an analog RF down-converter, and on-line beam tests at SXFEL verified its high sensitivity. The relative amplitude error of the electronics is 1.3× 10-4 at 80 pC, and the relative phase error is 8.4 fs. Even with a beam charge of 1 pC, the relative amplitude error of the electronics is better than 1.0× 10-3, and the relative phase error is 47.7 fs. It paves the way for large-scale applications of direct RF sampling electronics in SHINE. This represents a significant advancement in beam instrumentation at SHINE, leading to both a reduction in project costs and an enhancement in system reliability.
分类： 物理学 >> 核物理学 提交时间： 2025-05-11
摘要： The Shanghai High Repetition Rate XFEL and Extreme Light Facility (SHINE), currently under construction, is poised to become one of the most advanced free-electron laser (FEL) facilities globally. Designed to generate coherent X-rays with wavelengths ranging from 0.05 to 3 nm, and a maximum repetition rate of 1MHz. SHINE requires precise beam trajectory monitoring and stable alignment of electron and photon beams within the undulator, to meet these demands, cavity beam position monitors (CBPMs) with beam pipe diameters of 35 mm for the linear accelerator (LINAC) and bunch distribution sections, and 8 mm for undulators were developed. These systems requires transverse position resolution better than 1μm and 200 nm, respectively, for a single bunch of 100 pC. This paper details the design, fabrication, and performance evaluation of the CBPM system. The beam test bench has been established at the Shanghai Soft X-ray FEL facility (SXFEL), and preliminary beam experiments have shown that, with a bunch charge about 100 pC, the position resolution of the CBPM-35mm and CBPM-8mm are better than 312 nm and 41 nm, respectively, within the dynamic range of ±1 mm and ±300 μm. These results not only align with theoretical predictions but also surpass SHINE’s operational requirements, marking the highest resolution achieved by a cavity BPM system in an FEL facility under typical operational conditions.
点击量
待评议
点击量
下载量
评论
