On the Accuracy of Cs Beam Primary Frequency Standards
Abstract
Two effects which influence the accuracy of cesium beam primary frequency standards are examined: (A) second order Doppler shift, and (B) apparent frequency shift upon reversal of the static C-field (~60 mGauss) in which the hyperfine transitions occur. (A) A new technique for evaluating the velocity distribution of the Cs beam is presented. Using this method, the second order Doppler shift ((delta f)/f) approx. equal 4 x 10(exp -13) for our primary standards) can be evaluated to an uncertainty of (delta f)/f approx. equal 10(exp -15), an improvement on our previous uncertainty of 2 x 10(exp -14). (B) Progress in understanding the origins of the frequency shift of our primary standards as the static C-field is reversed in direction is reported. This effect has been eliminated in our evaluations of CsV, but not for the CsVI's. Application of these methods in evaluating NRC clocks gives no frequency shift outside previously published error budgets.
Document Details
- Document Type
- Technical Report
- Publication Date
- Nov 01, 1984
- Accession Number
- ADA498012
Entities
People
- A. G. Mungall
- C. Jacques
- J. Vanier
- J.-s. Boulanger
- R. J. Douglas
- Y. S. Li
Organizations
- National Research Council Canada