关键词: 微波钟, 四极-多极线型离子阱, 离子囚禁, 汞离子

Abstract:  A model of quadrupole-multipole separated and linear ion trap was built by SIMION simulation software, based on this model the first steady region when Mercury ions are trapped respectively in two trapping regions, i.e., quadrupole trap and sixteenpole trap was simulated in this work, and the characters of ion motion in two trapping regions were analyzed. In addition, the trapping volume and velocity distribution of the ion clouds in quadrupole-multipole ion trap as well as the process that Mercury ion clouds shuttle between two trapping regions were studied. When those ions trapped go into steady state the ion number density distribution in two trapping regions are discussed respectively. In particular, ion number degradation and compensation were demonstrated when Mercury ion clouds had been trapped and shuttled continuously in quadrupolemultipole separated trap. In the end, according to the analyses above, Doppler frequency shift associated with Mercury ion trapping in quadrupole-multipole ion trap was calculated and performance level of Mercury ion microwave clock was estimated.

Key words: Microwave clock, Quadrupole-multipole linear ion trap, Ion trapping, Mercury ion