Preliminary Research and Development of the Cesium Tube Accuracy Evaluation System

D.A. Howe, H.E. Bell, H. Hellwig, A. Demarchi
1974 28th Annual Symposium on Frequency Control  
A method has been developed which measures the velocity distribution of the atoms in a beam tube using the Ramsey dual interaction region principle. The method involves pulsing the R F excitation signal at a period related to the atoms' time-of-flight between the interactioL regions. The pulse method, with its ability to measure velocity distribution enables calculations of cavity phase shift and secondorder Doppler effect. This research has motivated the development of a system, complete unto
more » ... tem, complete unto itself, f o r determining the accuracy of cesium beam tubes. Design goals for the system are outlined. The system development to date is discussed. Frequency synthesis is accomplished at 5.00688MHz. This avoids frequency synthesis at X-band and thereby eliminates packaging and weight problems. A novel synthesizer design is used which incorporates a digital frequency lock of the 5.00688MHz VCXO. A resolution of 1. 4 millihertz/second is realizable; lock is within 2. 8 X lo-" at one second of a 5.0000 MHz reference with potential to better than 1 x IO-'* at one second. This synthesizer and its application to the accuracy evaluation system are discussed. Some results on the evaluationof commercial cesiumbeam tubes are given.
doi:10.1109/freq.1974.200043 fatcat:eypi73enuvcbfkjsm4nsgr2oee