ATOMIC VELOCITY DISTRIBUTIONS OUT OF HYDROGEN MASER DISSOCIATORS

Bernardo Jaduszliwer, Yat C. Chan

Abstract: We have determined velocity distributions of atonus effusing out of RF discharge hydrogen dissociators, of the type used in hydrogen masers. This work was motivated by long-term reliability issues related to the possible use of masers as frequency standards on board satellites. Chief amongst these issues is the maser's hydrogen budget, since many of the common failure modes of a maser involve either the hydrogen source or sink. Since the focusing properties of the state-selecting magnets are velocity-dependent, the overall hydrogen budget will depend not only on the dissociation efficiency, but also the velocity distribution of the hydrogen atoms leaving the dissociator. Many times, that distribution has been tacitly assumed to be Maxwellian at wall temperature, but that assumption is not necessarily valid. Our measurements show the distributions to be much narrower than Maxwellian, and to broaden as the hydrogen pressure in the dissoclator increases. Operating the dissociator to yield a relatively narrow velocity distribution and using a state selecting magnet well matched to that distribution may significantly improve the efficiency of hydrogen use by the maser.
Published in: Proceedings of the 21th Annual Precise Time and Time Interval Systems and Applications Meeting
November 28 - 30, 1989
Sheraton Hotel
Redondo Beach, California
Pages: 223 - 232
Cite this article: Jaduszliwer, Bernardo, Chan, Yat C., "ATOMIC VELOCITY DISTRIBUTIONS OUT OF HYDROGEN MASER DISSOCIATORS," Proceedings of the 21th Annual Precise Time and Time Interval Systems and Applications Meeting, Redondo Beach, California, November 1989, pp. 223-232.
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