【摘要】 <正> 氢原子钟的早期发展 上海天文台1970年开始氢原子钟的研制,1972年研制成功。一共研制了6台这种实验室型的氢原子钟。这些标准主要用于VLBI国际联测和频率测最的参考标准。它们的设计特征和性能指标在文章[1-3]中已经描述过了。图1是两台这种标准的照片。更多还原

【Abstract】 Progress in the development of hydrogen maser in recent years at Shanghai Observatory is summarized as follows:1. After the success of the first Chinese hydrogen Masor made at Shanghai Observatory in 1972, five more hydrogen masers with several improvements to the maser design, but still traditional structures, were made at Shanghai Observatory for VLBI Observations and time-keeping.2. In order to equip the Chinese VLBI network with a new generation of hydrogen maser, an integrated, rugged and easily transportable maser, was developed successfully in 1987. And so far five hydrogen masers of this kind have been in use in VLBI network.3. For time-keeping with hydrogen masers, a kind of one-maser autotuning system was developed at Shanghai Observatory.4. Meanwhile Shanghai Observatory is developing the third generation of hydrogen maser, an oscillating compact hydrogen maser which employs a compact cavity design, resulting in significant size and weight reductions compared to the conventional maser. This kind of maser is suitable for time-keeping because of its excellent long-term stability.In this paper, we describe the developments and performances of hydrogen Masers at Shanghai Observatory, as well as their applications,更多还原