Accession Number : ADP009118

Title :   Hydrogen Masers and Cesium Fountains at NRC,

Corporate Author : NATIONAL RESEARCH COUNCIL OF CANADA OTTAWA (ONTARIO)

Personal Author(s) : Boulanger, J.-S. ; Morris, D. ; Douglas, R. J. ; Gagne, M.-C.

Report Date : 02 DEC 1993

Pagination or Media Count : 11

Abstract : The NRC masers H-3 and H-4 have been operating since June/93 with cavity servo control. These low-flux active H masers are showing stabilities of about 10-15 from 1 hour to several days. Stability results are presented, and the current and planned uses of the masers are discussed. A cesium fountain primary frequency standard project has been started at NRC. Trapping and launching experiments with the goal of 7 m/s launches are beginning. We discuss our plans for a local oscillator and servo that exploit the pulsed aspect of cesium-fountain standards, and meet the challenge of 10-14t-1/2 stability 1 without requiring masers. At best, we expect to run this frequency standard initially for periods of hours each working day rather than continuously for years, and so frequency transfer to outside laboratories has been carefully considered 2. We conclude that masers (or other even better secondary clocks) are required to exploit this potential accuracy of the cesium fountain. We present and discuss our conclusion that it is feasible to transfer frequency in this way with a transfer-induced uncertainty of less than 10-15, even in the presence of maser frequency drift and random walk noise.

Descriptors :   *ACCURACY, *FREQUENCY STANDARDS, *MASERS, CESIUM, CONTROL, DRIFT, LOCAL OSCILLATORS, NOISE, RANDOM WALK, STABILITY, UNCERTAINTY, CAVITY RESONATORS, CANADA.

Subject Categories : Lasers and Masers
      Test Facilities, Equipment and Methods

Distribution Statement : APPROVED FOR PUBLIC RELEASE