Title :
A high stability atomic fountain clock using a cryogenic sapphire interrogation oscillator
Author :
Mann, A.G. ; Santarelli, G. ; Chang, S. ; Luiten, A.N. ; Laurent, Ph ; Salomon, C. ; Blair, D.G. ; Clairon, A.
Author_Institution :
Dept. of Phys., Western Australia Univ., Nedlands, WA, Australia
Abstract :
We describe the operation of the cesium fountain clock in the quantum limited regime, yielding a frequency stability of 5 10-14 τ -1/2, where τ is the integration time in seconds. The measured frequency instability varies as 1/√Nat where Nat is the number of detected atoms, up to Nat=6 105. Among the primary frequency standards, this is the best stability ever reported. The noise contribution of the fountain interrogation oscillator has been made negligible thanks to the ultra-low frequency noise in the 0.1-100 Hz Fourier frequency range of a cryogenic sapphire oscillator
Keywords :
atomic clocks; caesium; crystal oscillators; electron device noise; frequency stability; frequency standards; low-temperature techniques; sapphire; 0.1 to 100 Hz; Al2O3; Cs; Fourier frequency; atomic fountain clock; cryogenic sapphire interrogation oscillator; cryogenic sapphire oscillator; fountain interrogation oscillator; frequency instability; frequency stability; integration time; noise contribution; primary frequency standards; quantum limited regime; stability; ultra-low frequency noise; Atom lasers; Atomic beams; Atomic clocks; Atomic measurements; Cryogenics; Frequency measurement; Laser noise; Oscillators; Q factor; Stability;
Conference_Titel :
Frequency Control Symposium, 1998. Proceedings of the 1998 IEEE International
Conference_Location :
Pasadena, CA
Print_ISBN :
0-7803-4373-5
DOI :
10.1109/FREQ.1998.717871
