磁光阱中铯冷原子碰撞损失率系数的测量

Measurement on Collisional Loss Rate Coefficient of Cesium Cold Atoms in a Magneto-Optical Trap

利用磁光阱(MOT)技术获得了铯冷原子。通过观测磁光阱在装载过程中冷原子云荧光强度的变化,测量了不同俘获光功率下铯冷原子的碰撞损失率系数。在单个阱中完成了对碰撞损失率系数的测量。同时研究发现铯冷原子的碰撞损失率系数依赖于俘获光功率并随其增加而增大,该实验结果与Gallagher-Pritchard理论模型给出的结果一致,验证了辐射逃逸和精细结构交换碰撞是造成磁光阱中原子损失的主要原因,对于进一步提高磁光阱的俘获效率有重要意义。

Cold cesium atoms are obtained using magneto-optical trap （MOT） technology. Under different trapping laser powers, the collisional loss rate coefficients for cold cesium atoms were measured by observing the fluorescence intensity variance of cold atoms clouds when MOT was loading. The experiment was achieved in a single trap, thus it is convenient and easy. In addition, it is found that the collisional loss rate coefficient depends on and increases with trapping laser power, which is in agree with the Gallagher-Pritchard theoretical model. It validates that the radiative escape and fine-structure-changing collisions are the main reasons for cold atoms lossing in a MOT. The results are of significance for further improvement on trapping efficiency of MOT.