射频直采电子学用于高灵敏谐波腔系统
High-sensitivity resonant cavity monitor system with direct RF sampling electronics
摘要
谐振腔探头广泛应用于自由电子激光器中，并已被提议用于直线对撞机，以实现高分辨率的位置和相位测量。电子学是影响系统性能的主要限制因素。针对SHINE装置中使用的C波段腔体束流到达时间测量系统，研制了一套采用直接射频采样电子学的原型腔体监测系统，工作频率为TM010单极模的3.52 GHz。直接射频采样电子学通过替代传统的下变频电子学，简化了原本复杂的射频前端。该直接射频采样处理器使用的模数转换器在3.52 GHz下具有9 GHz的-3 dB带宽、最大2.6 GSPS的采样率以及8位有效位数。理论分析表明，直接数字下变频电子学的性能与模拟射频下变频器相当，在上海软X射线自由电子激光装置上的在线束流测试证实了其高灵敏度。在80 pC电荷量下，电子学的相对幅度误差为1.3×10⁻⁴，相对相位误差为8.4 fs。即使在1 pC的束团电荷量下，电子学的相对幅度误差仍优于1.0×10⁻³，相对相位误差为47.7 fs，这有利于直接射频采样电子学在SHINE装置中的大规模应用。这是SHINE装置束流仪器领域的一项重大进展，可降低项目成本并提高系统可靠性。
Abstract
Resonant cavity monitors are widely used in free-electron lasers (FELs) and have been proposed for linear colliders to obtain high-resolution position and phase measurements. The read-out electronics is a major limiting factor affecting the system performance. A prototype cavity monitor system with direct radio frequency (RF) sampling electronics was developed for the C-band cavity beam arrival monitors used at SHINE, operating at the TM010 monopole mode frequency of 3.52GHz. The direct RF sampling electronics simplified the otherwise complex RF front-end by applying traditional down-conversion electronics. The direct RF sampling processor used analog-to-digital converters with 3 dB bandwidth of 9GHz, maximum sampling rate of 2.6 GSPS, and 8 bits ENOB at 3.52GHz. A theoretical analysis demonstrated that direct-digital down-conversion electronics performed comparably to analog RF down-converters, and online beam tests at SXFEL confirmed its high sensitivity. The relative amplitude error of the electronics was 1.3104 at 80 pC, and the relative phase error was 8.4 fs. Even with a beam charge of 1 pC, the relative amplitude error of the electronics was better than 1.0 103 , and the relative phase error was 47.7 fs, facilitating large-scale applications of direct RF sampling electronics at SHINE. This represents a significant advancement in beam instrumentation at SHINE, which reduces project costs and enhances system reliability.关键词
SHINE/谐波腔/射频直采/电子学Key words
SHINE/resonant cavity/direct RF sampling/electronics引用本文复制引用
周逸媚,赖龙伟.射频直采电子学用于高灵敏谐波腔系统[EB/OL].(2026-06-23)[2026-06-27].https://chinaxiv.org/abs/202606.00127.学科分类
高电压技术/电气测量技术、电气测量仪器/无线电设备、电信设备/电子技术应用
