Long term stability of Hg/sup +/ trapped ion frequency standards

The standards report the development of a second /sup 199/Hg/sup +/ linear ion trap (LIT) based frequency standard to provide a capability for measuring stability beyond all existing frequency standards. Increased signal using a second light collection system together with a previously demonstrated atomic line Q /spl ap/ 2 /spl times/ 10/sup 12/ yields a performance better than /spl sigma//sub y/ (/spl tau/ = 7 /spl times/ 10/sup -14///spl tau//sup 1/2/). Sensitivity to the leading perturbations are measured to identify regulation requirements to obtain a stability of 10/sup -16/.<
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