J4 ›› 2012, Vol. 29 ›› Issue (2): 129-134.

• 光谱 •    下一篇

线型离子阱不同缓冲气体对汞离子的冷却效果研究

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   

  1. 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
  • 收稿日期:2011-03-31 修回日期:2011-05-05 出版日期:2012-03-28 发布日期:2012-02-28
  • 通讯作者: 李交美(1956-)湖北人,研究员,研究方向原子频标。 E-mail:jmlee@ wipm.ac.cn
  • 作者简介:杨玉娜(1985-), 女,研究生, 研究方向原子频标.E-mail: yangyuna189@ 126.com
  • 基金资助:

    National Natural Science Foundation of China11074282)

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

YANG Yu-na1,2,3, LIU Hao1,2,3, HE Yue-hong1,2,3, CHEN Yi-he1,2, SHE Lei1,2, LI Jiao-mei1,2   

  1. 1 Key Laboratory of Atomic Frequency Standard, Chinese Academy of Sciences, Wuhan 430071, China; 
    2 Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan 430071, China; 
    3 Graduate University of Chinese Academy of Sciences, Beijing 100080, China
  • Received:2011-03-31 Revised:2011-05-05 Published:2012-03-28 Online:2012-02-28

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办法,但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,得到在氩气中汞离子运动的衰减时间是最短的。还研究了为使钟跃迁(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。

关键词: 光谱学, 囚禁汞离子, 缓冲气体冷却, 二阶多普勒频移, 碰撞频移

Abstract:

Buffer gas cooling is the most effective and practical method to cool ions in ion trap. And the kind and the quantity of buffer gas are the key technologies in mercury ion microwave frequency standard experiments. We study buffer gas made of Helium, Neon or Argon to cool trapped Mercury ions (199Hg+) in a linear ion trap by introducing a resistance term in Mathieu’s equation. We find that the decay time of motion of 199Hg+ in Argon gas is the shortest. We get that the frequency shift of the clock transition (40.5 GHz) is minimum when the pressure of Helium is 10-5 Torr or when the pressure of Neon gas is 2.4×10-5 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.

Key words: spectroscopy, trapped Hg+ ions, buffer gas cooling, second-order Doppler shift, collision shift

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