文章研究了重力作用下对磁光阱中87Rb原子进行偏振梯度冷却后重新四极磁阱俘获的影响。研究了竖直放置四极线圈和水平放置四极线圈两种情形下,重力对原子偏振梯度冷却后四极磁阱重新俘获过程的作用,通过原子自由飞行吸收成像,观测到了原子的振荡。分析计算了87Rb原子|2,2〉态补偿重力时所需的磁场梯度B′,探究了磁场参数对于振荡现象的影响,从而选择了水平放置磁场线圈的方法,提高了原子偏振梯度冷却后四极磁阱的装载效率。

We studied the influence of gravity on 87Rb atoms recaptured by the quadrupole magnetic trap after Sisyphus cooling. When the quadrupole magnetic field coils were placed vertically and horizontally respectively,the gravity’s effect was investigated on recapturing atoms with the magnetic quadrupole trap. We have observed the oscillation of 87Rb atoms in the quadrupole magnetic trap by time-of-flight and absorption image. The magnetic field distribution in both cases was calculated and presented that 87Rb atoms’ oscillation came from the offset of center of the magnetic field due to gravity. After calculating and analyzing the magnetic field gradient B’ to balance the gravity for |2,2〉state of 87Rb atom,we explored 87Rb atoms oscillation,and chose the configuration with placing the magnetic field coils horizontally to increase the recapture efficiency of quadrupole magnetic trap.