A three-dimensional model of the gas cell atomic frequency standard

Initial calculations from a three-dimensional (3-D) model of the gas cell atomic frequency standard are discussed. In particular, a recent suggestion that the short-term stability of a gas cell standard might be improved by varying the microwave power is considered. Though the authors' results generally support the previous conclusion, they show that the degree of sensitivity is less than that predicted by one-dimensional (1-D) gas-cell frequency-standard model. This difference in predicted sensitivity is a manifestation of the three-dimensional model's more accurate treatment of the clock-cavity microwave field distribution. The more accurate treatment is highlighted by the three-dimensional model's determination of isoefficiency contours (contours showing spatial regions in the clock cavity that have equal efficiency for producing clock signal), and noting their spatial dependence on microwave power.<
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