Development of a Cryogenic Hydrogen Maser at the NPL
Abstract
We have been developing a prototype Cold Hydrogen Maser (CHM) for the past year. The novel features of this CHM, which is designed to operate initially at 4.2 K, are the use of low loss alumina, and later sapphire, in the fabrication of the microwave cavity; possible use of superconductors for shielding; use of a cryogenic amplifier; possible novel coating material; and a reliable rf discharge circuit for the dissociation of hydrogen. A numerical simulation has been performed to find the dimensions of the microwave cavity for the TEO11 mode and the model was confirmed experimentally. The system will be used to test various wall coatings adsorbed on top of a PTFE buffer underlayer. The CHM is expected to be used as a flywheel frequency standard at the NPL with medium-term stability of one part in 10(exp 14) or better.
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 01, 1992
- Accession Number
- ADA494564
Entities
People
- R. Mossavati
Organizations
- National Physical Laboratory