利用补偿线圈提高塞曼减速器效率的理论及实验研究

Theoretical and Experimental Study of Rising Zeeman Slower Efficiency use compensatory Coils

研究了用于锶原子光晶格光钟原子冷却的塞曼减速器,应用增添补偿线圈的方法可以延长减速器的有效减速距离和增大减速器末端的磁场梯度,进而增加一级冷却俘获锶原子的数目,理论分析采用该方法实现的塞曼减速器较使用单一线圈塞曼减速器可以增加31.17%的俘获原子数目;飞行时间法测量了减速前后原子束中原子的速度分布,原子的最可几速度由380m/s降为43m/s,分布线宽相应变窄。荧光法测量俘获原子数目表明在相同实验条件下,应用补偿线圈后磁光阱俘获原子数目从1.26×106提高到1.81×106,增加30.4%。

We present a Zeeman Slower used for strontium optical clock. Adding compensatory coil can increase slower actual distance and ultimate magnetic field gradient, thus increasing captured atom number in Strontium first cooling stage （blue MOT）. Theoretical analysis Zeeman slower constructed in new method can trapping 31. 17% more atoms than made by a single set of coil. We measured the velocity distribution of atomic beam use time-of-flight method. The most probable velocity decreased from 380m/s to 43m/s, the width also become narrower. Experiment study show that two coils Zeeman slower can trap 1.81 X 10^688Sr atoms in first cooling stage. While single coil Zeeman slower can trap 1.26 X 10^6 atoms in same experimental condition. Therefore adding compensatory coils increase trapping atom number by 30.4%, consistent with the theoretical analysis.