| 摘要 |
PURPOSE:To improve the stabilization of standard frequency, by cleaning and regeneration wherein the temperature of contaminated ionizer of a detector in an atomic tube in stand-by is set automatically higher than the normal temperature during the operation period of working atomic beam tube. CONSTITUTION:A comparison/discrimination signal input into a change-over equipment 26 makes atomic beam tubes 21 and 22 taking minimum frequency difference operate as working tubes, and keeps an atomic beam tube 23 providing a maximum frequency difference in switching-over state in stand-by. The signal from a frequency comparison/discrimination equipment 24 makes an ionizer heating power source controller 27 operate, which controls the heating temperature of ionizer of the detector in the atomic beam tube 23 in stand-by in the range of several hundreds degree C higher than the normal operation temperature. Then Cs contaminant and the like deposited on the ionizer surface are regenerated by cleaning method of evaporation elimination. Whenever the atomic beam tube with maximum frequency difference appears, the regeneration means performs automatically regeneration process, so that the S/N characteristics of each working atomic beam tube are kept always in the optimum condition, and the stability of standard frequency is improved. |
