摘要The NIM4 caesium fountain clock has been operating stably and sub-continually since August 2003. We present our improvements on NIM4 in 2005--06 and the most recent evaluation for its frequency shifts with an uncertainty of 5×10-15. A 203-day comparison between NIM4 and GPS time shows an agreement of 2×10-14. Finally the construction of the NIM5 transportable caesium fountain clock is briefly reported.
Abstract：The NIM4 caesium fountain clock has been operating stably and sub-continually since August 2003. We present our improvements on NIM4 in 2005--06 and the most recent evaluation for its frequency shifts with an uncertainty of 5×10-15. A 203-day comparison between NIM4 and GPS time shows an agreement of 2×10-14. Finally the construction of the NIM5 transportable caesium fountain clock is briefly reported.
(Tuning forks, frequency standards; frequency measuring and recording instruments; time standards and chronographs)
引用本文:
LI Tian-Chu;LI Ming-Shou;LIN Ping-Wei;WANG Ping;CHEN Wei-Liang;LIU Nian-Feng;LIN Yi-Ge. Improvements and New Evaluation of NIM4 Caesium Fountain Clock at NIM in 2005--2006[J]. 中国物理快报, 2007, 24(5): 1177-1179.
LI Tian-Chu, LI Ming-Shou, LIN Ping-Wei, WANG Ping, CHEN Wei-Liang, LIU Nian-Feng, LIN Yi-Ge. Improvements and New Evaluation of NIM4 Caesium Fountain Clock at NIM in 2005--2006. Chin. Phys. Lett., 2007, 24(5): 1177-1179.
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2007, Vol. 24 
