Title :
Improved accuracy evaluation of the NPL-CsF2 primary frequency standard
Author :
Li, Ruoxin ; Gibble, Kurt ; Szymaniec, Krzysztof
Author_Institution :
Dept. of Phys., Pennsylvania State Univ., University Park, PA, USA
Abstract :
Presented is quantitative evaluation of two leading uncertainties in the NPL-CsF2 fountain frequency standard. The distributed cavity phase shift evaluation is based on recent theoretical model where the cavity field is decomposed into a series of 2D Fourier components in azimuthal angle in the cylindrical cavity. Predictions of the model are reproduced experimentally. The microwave lensing effect is caused by dipole forces originating from radial variation of the microwave field amplitude and cavity apertures. The new evaluation of the two effects together with other recent improvements reduce the total type B uncertainty of NPL-CsF2 to 2.3 × 10-16.
Keywords :
frequency standards; 2D Fourier components; NPL-CsF2 fountain frequency standard; NPL-CsF2 primary frequency standard; azimuthal angle; cavity apertures; cylindrical cavity; dipole forces; distributed cavity phase shift evaluation; improved accuracy evaluation; microwave field amplitude; microwave lensing effect; Accuracy; Apertures; Atomic clocks; Atomic measurements; Cavity resonators; Microwave imaging; Uncertainty;
Conference_Titel :
Frequency Control and the European Frequency and Time Forum (FCS), 2011 Joint Conference of the IEEE International
Conference_Location :
San Fransisco, CA
Print_ISBN :
978-1-61284-111-3
DOI :
10.1109/FCS.2011.5977817
