The NASA/GSFC Hydrogen Maser Program: A Review of Recent Data
Abstract
The NASA/Goddard Space Flight Center Hydrogen Maser Program has had as goals for many years the development of improved field operable hydrogen masers, the improvement of existing field operable hydrogen masers and the development of novel hydrogen maser frequency standards. This paper presents a review of recent data on the phase and frequency stability of new NR field operable hydrogen masers showing that the frequency stability has been improved substantially to virtually the NR level . VLBI data is presented on the phase difference between NX-2 at Owens Valley, CA and NR-2 at Fort Davis, TX showing, after removal of a constant frequency drift , a 350 ps RMS phase stability. The role of a temperature control chamber in improving the long term stability of hydrogen masers is discussed. A quartz cavity liner designed to retrofit into existing NR, NP, and NX microwave cavity structures has been installed in an NR maser and has been shown to reduce the cavity temperature coefficient by a factor of 8. Data is presented showing the stability of this maser against other NR masers. A completely quartz cavity and storage bulb structure, called the integral cavity, which will also retrofit into the NR, NX, and NP masers is being developed that should reduce the cavity temperature coefficient by a factor of 25 or more and improve the maser's frequency stability under mechanical shock. Data is presented on the recent progress in the development of an external bulb variable volume hydrogen maser primary frequency standard.
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 01, 1982
- Accession Number
- ADA497798
Entities
People
- Alvin G. Bates
- Lauren J. Rueger
- Mary Chiu
- Peter Dachel
- Richard Kunski
- Robert Kruger
- S. C. Wardrip
- Victor S. Reinhardt
Organizations
- Johns Hopkins University