摘要
我国研制的氢原子频标在陕西天文台运行已二十多年了 ,对我们的时间工作起到了重要的作用。 1 979年至 1 980年间 ,陕西天文台没有铯原子钟 ,氢频标曾作为基准钟 ,为我台原子时尺度的建立立下首功。 1 983年后 ,长期性能得到改进。1 993年 ,在我国氢原子钟同行中 ,率先在国际时间局取到权。随着科学技术的发展 ,对时间工作精度的要求日益提高 ,陕西天文台仍然需要世界一流水平的氢原子频标。
In this paper, the history of 20 years of the CSAO H masers made in China is described. The first two H masers were introduced at CSAO in May, 1978. In 1979, the wall shift constant was determined through experiments, and the uncertainty of H masers was calculated independently as less than ±2×10 -12 . At that time, there was on Cs clock at CSAO. So before April, 1980, the atomic time scale of CSAO was based on a group of Ru clocks, which were calibrated with H masers. In 1981, the accuracy of CSAO H maser against TAI was tested to be (3±5×10 -13 . During the period of 1982～1993,the long term performance of the masers was improved. The cavity temperature coefficient was decreased to under 100Hz/℃ ,by temperature compensation, and the cavity temperature was decreased from 50℃ to 28.9℃. Meanwhile the atomic spectral line quality factor Q was increased to 2.8×10 9,1.5 times as it had been before. The stability for 1 day was improved from (1～3)×10 -13 to (2～4)×10 -14 . The reliability of the H masers was further improved, after a new H maser receiver made in CSAO had been introduced into the system in 1989, and since then the continuous data series of the maser was obtained, This H maser is the first one in China to gain none zero weight in TAI system. In this paper, the present situation of H maser in the world in described. Commercial H maser and their performances as well as their applications in some famous time laboratories are introduced. H maser will be very useful in high precision time and frequency measurements and will be important for time service at CASO, since it is of excellent performance in stability.
出处
《陕西天文台台刊》
CSCD
1999年第2期123-127,共5页
Publications of The Shaanxi Astronomical Observatiory
