Precise calibration of cavity forward and reflected signals using low-level radio-frequency system

• 作者: Jin-Ying Ma Feng Qiu Long-Bo Shi Zheng-Long Zhu Tian-Cai Jiang Zong-Heng Xue Ke-An Jin Qi Chen Cheng-Ye Xu Xing-Hao Ding Zheng Gao Lie-Peng Sun Gui-Rong Huang Yuan He
• 来源期刊: 核技术（英文版）
• 年，卷（期）: 2022,（1）
• 所属期刊栏目: ACCELERATOR, RAY TECHNOLOGY AND APPLICATIONS
• 页码范围: 35-43
• 页数: 9页
• 语种: 英文

摘要

Precise measurements of the cavity forward (Vf)and reflected signals (Vr) are essential for characterizing other key parameters such as the cavity detuning and for-ward power.In practice,it is challenging to measure Vf and Vr precisely because of cross talk between the forward and reflected channels (e.g.,coupling between the cavity reflected and forward signals in a directional coupler with limited directivity).For DESY,a method based on the cavity differential equation was proposed to precisely cal-ibrate the actual Vf and Vr.In this study,we verified the validity and practicability of this approach for the Chinese ADS front-end demo superconducting linac (CAFe) facility at the Institute of Modern Physics and a compact energy recovery linac (cERL) test machine at KEK.At the CAFe facility,we successfully calibrated the actual Vf signal using this method.The result demonstrated that the direc-tivity of directional couplers might seriously affect the accuracy of Vf measurement.At the cERL facility,we calibrated the Lorentz force detuning (LFD) using the actual Vf.Our study confirmed that the precise calibration of Vf significantly improves the accuracy of the cavity LFD measurement.