The NIM4 cesium fountain clock has been operating stably and sub-continually since Aug.2003.In this paper we present improvements on NIM4 in 2005-2006 and the most recent evaluation for its frequency shifts with an un...The NIM4 cesium fountain clock has been operating stably and sub-continually since Aug.2003.In this paper we present improvements on NIM4 in 2005-2006 and the most recent evaluation for its frequency shifts with an uncertainty of 5E-15.A 220 days comparison between NIM4 and GPS showed an agreement of 2E-14.Finally the construction of a NIM5 transportable cesium fountain clock is briefly reported.展开更多
文摘The NIM4 cesium fountain clock has been operating stably and sub-continually since Aug.2003.In this paper we present improvements on NIM4 in 2005-2006 and the most recent evaluation for its frequency shifts with an uncertainty of 5E-15.A 220 days comparison between NIM4 and GPS showed an agreement of 2E-14.Finally the construction of a NIM5 transportable cesium fountain clock is briefly reported.
