Autonomous cryogenic sapphire oscillators employing low vibration pulse-tube cryocoolers at NMIJ

8th Symposium on Frequency Standards and Metrology 2015

Ikegami, Takeshi^1 ; Watabe, Ken-Ichi^1 ; Yanagimachi, Shinya^1 ; Takamizawa, Akifumi^1 ; Hartnett, John G.^2

Radio-Frequency Standards Group, National Metrology Institute of Japan (NMIJ), AIST, Ibaraki, Tsukuba, Japan^1

Institute of Photonics and Advanced Sensing (IPAS), School of Physical Sciences, University of Adelaide, Adelaide, Australia^2

关键词: Allan deviation;    Averaging time;    Cryogenic sapphire oscillators;    Cryogenic sapphire resonator;    Liquid helium;    Low vibration;    Pulse tube cryocoolers;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/723/1/012032/pdf
DOI  :  10.1088/1742-6596/723/1/012032

来源: IOP

【 摘 要 】

Two liquid-helium-cooled cryogenic sapphire-resonator oscillators (CSOs), have been modified to operate using cryo-refrigerators and low-vibration cryostats. The Allan deviation of the first CSO was evaluated to be better than 2 × 10-15for averaging times of 1 s to 30 000 s, which is better than that of the original liquid helium cooled CSO. The Allan deviation of the second CSO is better than 4 × 10-15from 1 s to 6 000 s averaging time.