A NEW RING TRAP FOR FREQUENCY-STANDARD APPLICATIONS

We propose a new ring ion-trapping system, that is advantageous for us e in frequency-standard applications and ultrahigh-resolution spectros copy. The ring trap can store a large number of ions with low suscepti bility to the second-order Doppler effect. The ring-trap electrodes al so form a wide-band microwave cavity. Microwave radiation trapping dur ing the probe cycle makes it possible to meet the Lamb-Dicke criterion more satisfactorily than with an rf/dc hybrid linear trap, in which t raveling microwave power is used. This technique yields an increased S /N ratio because the microwave probing power is absorbed in the fundam ental mode rather than in the sidebands induced by ion motion in the t rap. This paper presents an analytical model of the ring-trap system a nd estimates of the main parameters of the ring trap.