线型离子阱中不同缓冲气体对汞离子的冷却效果研究(英文)  

Cooling effect of different buffer gas of trapped mercury ions in a linear ion trap

作　　者：杨玉娜[1,2,3] 柳浩[1,2,3] 何跃宏[1,2,3] 陈义和[1,2] 佘磊[1,2] 李交美[1,2] 

机构地区：[1]中国科学院原子频标重点实验室,湖北武汉430071 [2]中国科学院武汉物理与数学研究所,湖北武汉430071 [3]中国科学院研究生院,北京100080

出　　处：《量子电子学报》2012年第2期129-134,共6页Chinese Journal of Quantum Electronics

基　　金：National Natural Science Foundation of China(11074282)

摘　　要：缓冲气体冷却是将离子阱中的离子云冷却的最有效和实用的方法,缓冲气体的种类和数量是汞离子微波频标实验的关键技术。通过在马修方程中引入阻力项的方法,研究了线型离子阱中氦气、氖气、氩气对囚禁的汞离子的冷却效果,结果表明在氩气中汞离子运动的衰减时间最短。研究了为使钟跃迁(40.5 GHz)的频率移动最小,所需氦气的压强为10^(-5)Torr,氖气的压强为2.4×10^(-5)Torr。考虑到缓冲气体对汞离子的冷却效率和对气体压强的敏感性,氖气要比氦气、氩气更适合作缓冲气体。Buffer gas cooling is the most effective and practical method to cool ions in ion trap. The kind and quantity of buffer gas are the key technologies in mercury ion microwave frequency standard experiments. Buffer gas made of helium, neon or argon was studied to cool trapped mercury ions （^199Hg^＋） in a linear ion trap by introducing a resistance term in Mathieu＇s equation. It＇s found that the decay timeof motion of ^199Hg^＋ in argon gas is the shortest, and the frequency shift of the clock transition （40.5 GHz） is minimum when the pressure of helium is 10-5 Torr or the pressure of neon gas is 2.4 × 10-2 Torr. Neon is the most suitable buffer gas among helium, neon and argon, considering the decay time-constant of motion of ^199Hg^＋in buffer gases and ^199Hg^＋clock transition shift＇s sensitivity to the change of the pressure of buffer gas.

关 键 词：缓冲气体 冷却效果 汞离子 离子阱 线型 气体压强 气体冷却 衰减时间 

分 类 号：O561.5[理学—原子与分子物理]