title: An evaluation of the frequency shift caused by collisions with background gas in the primary frequency standard NPL-CsF2.
abstract: Collisions between cold cesium atoms and background gas atoms at ambient temperature reduce the cold atom signal in a fountain clock and at the same time produce a shift in the measured clock frequency. We evaluate the shift in the NPL-CsF2 cesium fountain primary frequency standard based on measurements of the fractional loss of cold atoms from the atomic cloud during the interrogation time combined with a model by Gibble that quantifies the relationship between the loss and the frequency shift.
authors.forename: Krzysztof
authors.initials: K
authors.lastname: Szymaniec
authors.forename: Stephen
authors.initials: S
authors.lastname: Lea
authors.forename: Kun
authors.initials: K
authors.lastname: Liu
mesh_terms: D016477:Artifacts; D002586:Cesium / Q000737:chemistry* / Q000592:standards*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005459:Fluorides / Q000737:chemistry* / Q000592:standards*; D005740:Gases / Q000737:chemistry*; D009991:Oscillometry / Q000295:instrumentation* / Q000592:standards; D013997:Time Factors; D014481:United States
chemical_list: D005740:Gases; D002586:Cesium; D005459:Fluorides; C027754:cesium fluoride