New ion trap for frequency standard applications

We have designed a novel linear ion trap which permits storage of a large number of ions with reduced susceptibility to the second‐order Doppler effect caused by the rf confining fields. This new trap should store about 20 times the number of ions as a conventional rf trap with no corresponding increase in second‐order Doppler shift from the confining field. In addition the sensitivity of this shift to trapping parameters, i.e., rf voltage, rf frequency, and trap size, is greatly reduced.