主动型氢原子钟原子弛豫时间的测量和分析  

Measurement and Analysis of Atomic Relaxation Time in Active Hydrogen Atomic Clocks

作　　者：梁悦 谢勇辉[1] 陈鹏飞[1] LIANG Yue;XIE Yong-hui;CHEN Peng-fei(Shanghai Astronomical Observatory,Chinese Academy of Sciences,Shanghai 200030;University of Chinese Academy of Sciences,Beijing 100049,China)

机构地区：[1]中国科学院上海天文台,上海200030 [2]中国科学院大学,北京100049

出　　处：《波谱学杂志》2022年第4期476-482,共7页Chinese Journal of Magnetic Resonance

基　　金：中国科学院重点部署项目(E183051).

摘　　要：氢原子钟的原子弛豫时间是原子系统经过选态去除基态超精细能级(F=0,m_(F)=0)态和(F=1,m_(F)=-1)态原子后,部分氢原子从(F=1,m_(F)=0)态跃迁至(F=0,m_(F)=0)态直至原子系统达到平衡状态所需的时间,该参数反映了原子的寿命,并直接影响氢原子钟的稳定度指标.为了测量主动型氢原子钟的弛豫时间,进而评估其性能,通过Raspberry Pi(RPI)产生时序信号,控制数字衰减器和电离源供电电路的继电器,从而控制微波探测信号的开启和原子束流的通断,并与数据采集等电路组成了氢原子自由感应衰减测试系统.通过对采集的自由感应衰减信号建模拟合,测算了氢原子钟的弛豫时间.该方法对于评估和优化原子线宽,改进主动型氢原子钟稳定度指标具有重要的参考意义.The atomic relaxation time of a hydrogen atomic clock is the time required for atomic system after the selected state removing the atoms of the ground state hyperfine energy level(F=0,m_(F)=0)and(F=1,m_(F)=-1)state to change from the(F=1,m_(F)=0)state to the(F=0,m_(F)=0)state until the atomic system reaches equilibrium.This parameter reflects the lifetime of atoms and directly affects performance of hydrogen clock.In order to measure the relaxation time of active hydrogen atomic clock and thus evaluate its performance,hydrogen atomic relaxation test system was established,which was composed of a Raspberry Pi(RPI),signal generator,digital attenuation,microwave detection,and data acquisition circuits.RPI generates timing signal to control the relay of digital attenuator and ionization source power supply circuit,so as to control the opening of microwave detection signal and the on-off of atomic beam current.The relaxation time of the hydrogen atomic clock is measured by data fitting of the acquired free induction decay signals.This method is important for optimizing the atomic linewidth and improving the performance of the active hydrogen clock.

关 键 词：主动型氢原子钟 原子弛豫时间 Raspberry Pi(RPI) 

分 类 号：O482.53[理学—固体物理]