铯原子磁力仪中缓冲气体的最佳条件研究(英文)

Optimized Condition for Buffer Gas in Cesium Atomic Magnetometer

介绍了基于共振吸收法检测椭圆率变化的全光铯原子磁力仪的基本原理。为了降低工作介质碱金属铯原子的横向弛豫速率,延长自旋极化时间,使磁力仪达到较高的磁测灵敏度,通常将最外层电子排列稳定的惰性气体He和双原子分子N2作为缓冲气体充入铯原子气室中,这样既能有效地减少极化原子与气室壁碰撞的几率,又可以很好地避免辐射陷阱现象。分析了He和N2的压强对Cs原子极化程度及磁力仪输出信号的影响,给出了100℃时实现无自旋交换弛豫铯原子磁力仪的最佳压强:He约为3.9×104 Pa,N2约为3.6×103 Pa。

This paper described the principle of an all-optical cesium magnetometer based on absorptive detection. In order to reduce transverse relaxation rate and to maximize spin polarization time of the alkali-metal atoms, it is usually to fill the inert gas He and the diatomic molecule N2 which are used as buffer gases into the cell to achieve high measuring sensitivity. Not only the collision probability of polarized atoms with the cell wall but also the radiation trapping can be reduced or avoid by this approach. The relationships between the output signals of this magnetometer with buffer gas pressures were expressed here. Mter a detail theoretical analysis, it was found that the optimal gas pressure of the buffer gas was about 3.9×10^4 Pa for helium （He） and 3.6 × 103 Pa for nitrogen （N2）.