Accurate Evaluation of Microwave-Leakage-Induced Frequency Shifts in Fountain Clocks

作     者：房芳 刘昆 陈伟亮 刘年丰 所睿 李天初 

作者机构：Time and Frequency Division National Institute of Metrology Beijing 100013 

出 版 物：《Chinese Physics Letters》 (中国物理快报（英文版）)

年 卷 期：2014年第31卷第10期

页      面：18-21页

核心收录：

学科分类：080904[工学-电磁场与微波技术] 0810[工学-信息与通信工程] 080801[工学-电机与电器] 0808[工学-电气工程] 0809[工学-电子科学与技术（可授工学、理学学位）] 08[工学] 080402[工学-测试计量技术及仪器] 0804[工学-仪器科学与技术] 081001[工学-通信与信息系统] 

基　　金：Supported by the National Natural Science Foundation of China under Grant No 11174260  and the National Basic Research Program of China under Grant No 2010CB922902 

主　　题：MICROWAVE measurements STRAY currents FREQUENCY shift keying BLOCH equations (Physics) WAVE functions 

摘      要：We report theoretical calculations of the transition probability errors introduced by microwave leakage in Cs fountain clocks, which will shift the clock frequency. The results show that the transition probability errors are affected by the Ramsey pulse amplitude, the relative phase between the Ramsey field and the leakage field, and the asymmetry of the leakage fields for the upward and downward passages. This effect is quite different for the leakage fields presenting below the Ramsey cavity and above the Ramsey cavity. The leakage-field-induced frequency shifts of the NIM5 fountain clock in different cases are measured. The results are consistent with the theoretical calculations, and give an accurate evaluation of the leakage-field-induced frequency shifts, as distinguished from other microwave-power-related effects for the first time.