Joint Conference of the European Frequency and Time Forum and IEEE International Frequency Control Symposium (EFTF/IFCS)
Ultra-stable Hg/sup +/ trapped ion frequency standard
John D. Prestage, Robert L. Tjoelker, G.J. Dick, Lute Maleki
Abstract
The authors report the development of a fieldable frequency standard based on /sup 199/Hg/sup +/ ions confined in a hybrid RF/DC linear ion trap. This trap permits storage of large numbers of ions with reduced susceptibility to the second-order Doppler effect caused by the RF confining fields. A 160-mHz-wide atomic resonance line for the 40.5-GHz clock transition is used to steer the output of a 5-MHz crystal oscillator to obtain a stability of 2*10/sup -15/ for 24000 second averaging times. For long averaging intervals measurements are limited by instabilities in available hydrogen maser frequency standards.>