Results of Two Years of Hydrogen Maser Clock Operation at the U.S. Naval Observatory and Ongoing Research at the Harvard-Smithsonian Center for Astrophysics
Abstract
Two SAO VLC-11 hydrogen masers have been in service at the U.S. Naval Observatory in September 1983. The systematic frequency drifts have been measured against the U.S.N.O. time scale and their causes identified. The drift is now less than 1x10 to the minus 15th power per day. By operating masers at cryogenic temperatures with wall coatings of CF4 frozen in place, we have determined that the conventional coatings of the maser hydrogen storage bulbs have 3 times the surface area than is projected geometrically. There are excellent prospects for extending the storage time by a factor of 3 and for reducing the wall shift. Present efforts are underway to realize - an atomic hydrogen maser to operate at 0.4K with storage volume coatings of superfluid helium 4. The stability expected of the device is in the 10 to the minus 18th power region for intervals beyond 1 hour.
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 01, 1985
- Accession Number
- ADA494198
Entities
People
- E. M. Mattison
- H. P. Godfried
- I. F. Silvera
- R. F. Vessot
- R. L. Walsworth Jr.
- W. J. Klepczynski
Organizations
- United States Naval Observatory