Chinese Physics B
Evaluation of the frequency instability limited by Dick effect in the microwave 199 Hg + trapped-ion clock
Yi-He Chen, Lei She, Man Wang, Zhihui Yang, Hao Liu, Jiaomei Li
Abstract
In the microwave 199 Hg + trapped-ion clock, the frequency instability degradation caused by the Dick effect is unavoidable because of the periodical interrogating field. In this paper, the general expression of the sensitivity function g ( t ) to the frequency fluctuation of the interrogating field with Nπ -pulse ( N is odd) is derived. According to the measured phase noise of the 40.5-GHz microwave synthesizer, the Dick-effect limited Allan deviation of our 199 Hg + trapped-ion clock is worked out. The results indicate that the limited Allan deviations are about and respectively in the linear ion trap and in the two-segment extended linear ion trap under our present experimental parameters.