Accession Number : ADA255902
Title : Determining Optimum C-Field Settings that Minimize Output Frequency Variations in Cesium Atomic Frequency Standards
Descriptive Note : Technical rept.
Corporate Author : AEROSPACE CORP EL SEGUNDO CA ENGINEERING AND TECHNOLOGY GROUP
Personal Author(s) : Karuza, S K ; Johnson, W A ; Voit, F J ; Hurrell, J P
Report Date : 15 Dec 1991
Pagination or Media Count : 24
Abstract : De Marchi at the National Institute of Standards and Technology (NIST) performed an experiment on Hewlett-Packard cesium (Cs) frequency standards, in which he showed that there exist optimum values of the C-field that make the output frequency insensitive to variations in microwave power. Moreover, and most important, De Marchi demonstrated that the long-term stability of the Cs standard was improved at these optimum values of the C- field. To see if these results could be obtained with standards made by different manufacturers and having different modulation schemes and Cs tube designs, we performed a similar study using a completely automated measurement system on four Cs standards made by two other manufacturers. Our results, similar to those of De Marchi, showed that there are similar optimum C-field settings in these standards; furthermore, they showed that it may be more important to tune the microwave cavity precisely to the center Cs resonance frequency (fo) than it is to set the C-field at an optimum value. The best procedure, of course, is to do both, i.e., tune the cavity to the Cs resonance frequency as well as set an optimum C-field.
Descriptors : *FREQUENCY STANDARDS , FREQUENCY , OUTPUT , MEASUREMENT , STABILITY , MICROWAVES , CAVITIES , CESIUM , RESONANCE , STANDARDS , TUNING , POWER , VALUE , MODULATION , TUBES
Subject Categories : Test Facilities, Equipment and Methods
Distribution Statement : APPROVED FOR PUBLIC RELEASE