Molecular beam tube frequency biases due to distributed cavity phase variations

Power dependence of distributed cavity phase-induced frequency biases in atomic fountain frequency standards

“…This is as it should be. If the imaginary and real parts of the field have the same spatial dependence, then the distributed cavity phase is constant (3), and the frequency shift vanishes exactly. In fact, the power dependence exists whenever the temporal dependance (as seen by the atoms) of the real and imaginary parts of the field are different, which they will be in any cavity with below cutoff waveguides in the endcaps.…”

“…T he subject of frequency shifts in atomic frequency standards caused by distributed cavity phase is not new; it goes back to the earliest days of the thermal beam standards [1], [2] and has been the subject of continuing work both theoretical and experimental over the last 50 years [3]- [5]. Laser-cooled fountain frequency standards pose significantly different problems with respect to distributed cavity phase than the thermal beam standards.…”

Microwave time and frequency standards

“…Cesium beam standard. The most significant frequency bias is cavity phase shift [Becker, 1976;Mungall, 1978;Wineland et al, 1977;Hellwig et al, 1975a] Owing to a difference in cavity phase between the two ends of the cavity, as well as to a variation of cavity phase across the beam cross section (distributed cavity phase shift) [Jarvis, 1975;Garvey et al, 1978;Allan et al, 1977;Hellwig et al, 1975a;Becker, 1978], frequency shifts can be approximated by…”

“…The major accuracy limitation in cesium is probably related to the cavity phase shift and, in particular, to the distributed cavity phase shift. The latter effect is due to a nonuniform distribution of the phase of the interrogating electromagnetic radiation across the beam [Hellwig et al, 1975a, Jarvis, 1975 Such effects at the detector may relate to electric potential changes affecting ion collection at the hot wire Becker, 1978]. In addition, cesium standards may be stability limited owing to magnetic field effects, which include fluctuations in the average value of the magnetic field as well as in the distribution of the field along and across the beam.…”

On the power dependence of extraneous microwave fields in atomic frequency standards

“…[3][4][5][6][7][8]. Laser-cooled fountain frequency standards pose problems with respect to both distributed cavity phase and microwave leakage different from those associated with thermal beam standards.…”