학술논문

BNM-SYRTE fountains: recent results
Document Type
Periodical
Source
IEEE Transactions on Instrumentation and Measurement IEEE Trans. Instrum. Meas. Instrumentation and Measurement, IEEE Transactions on. 54(2):833-836 Apr, 2005
Subject
Power, Energy and Industry Applications
Components, Circuits, Devices and Systems
Stability
Atom optics
Optical resonators
Atomic beams
Frequency estimation
Atomic clocks
Physics
Local oscillators
Masers
Frequency measurement
Atomic fountain
cold collisions
frequency comparison
frequency shifts
Language
ISSN
0018-9456
1557-9662
Abstract
Recent improvements of Bureau National de Me/spl acute/trologie Syste/spl grave/mes de Re/spl acute/fe/spl acute/rence Temps Espace (BNM-SYRTE) fountains FO1 and FO2 are described. Fractional frequency instabilities of 2.9/spl times/10/sup -14//spl tau//sup -1/2/ for FO1 and 1.6/spl times/10/sup -14//spl tau//sup -1/2/ for FO2 have been demonstrated. A preliminary estimate of the systematic frequency shifts gives an uncertainty of /spl plusmn/7.2/spl times/10/sup -16/ for FO1 and /spl plusmn/6.5/spl times/10/sup -16/ for FO2. Furthermore, we present a direct comparison between the two fountains. When a real-time measurement of the collisional shift is included, we observe a stability of the comparison of 5.0/spl times/10/sup -14//spl tau//sup -1/2/ and a frequency difference of /spl delta/=4/spl times/10/sup -16/, well within the combined uncertainties.