A study of cryogenic techniques for operating hydrogen masers

Cryogenic Techniques are applied to the Atomic Hydrogen Maser Frequency Standard to extend the storage time of the atoms and reduce the thermal noise accompanying the signal and within the resonance linewidth. Oscillation has been achieved below 25K using wall coatings of frozen CF4. This method will be used to determine the wall interaction for Atomic Hydrogen on a variety of other surfaces. A pair of new masers is under construction so that frequency stability improvement can be measured. Stability at the 1 x 10 to the minus 16th power level in delta f/f for averaging time intervals of 1,000 seconds is expected at temperatures below 30K.