双真空主动型氢脉泽真空系统设计

Design of Dual-Vacuum System Dedicated to Active Hydrogen Maser

清洁、抽速稳定的高真空系统是氢脉泽工作必不可少的组成部分之一。文章详细介绍了双真空主动型氢脉泽真空系统的组成及各个组成部分的设计思路、方法。内容涉及真空的获得、真空泵的选择、氢脉泽物理部分双真空系统设计、流导及抽速的计算、泵体结构的设计和实验验证。实验发现,设计完毕的氢脉泽双真空系统保温效果较以前大幅改善,内外真空室本底流量为0.1 mA,工作流量值稳定在0.7mA时氢脉泽稳定输出-105 dBm信号,关闭流量后内真空抽真空本底时间约为8 min。表明内外真空室离子泵均达预期设计指标且工作正常。此外,该设计还进一步减小了脉泽体积、减轻了其重量,向氢脉泽小型化迈出了坚实一步。

The dual-vacuum system, dedicated to the active hydrogen maser, was designed, constructed, and tested. The so-called dual vacuum system mainly consists of two vacuum chambers： one is called the high vacuum inner chamber, where active hydrogen maser is generated; the other is the low vacuum outer chamber, where the auxiliary units, including the EM shields,coils heaters and control units,etc, are installed,allowing exposure to air in routine maintenance. The dis- cussion centered on the design considerations of the dual-vacunm system. The experimental tests were performed in the lab-built, prototyped dual vacuum system with satisfactory results. The strengths of the newly-developed dual-vacuum sys- tem, such as the volume and weight reduction of the maser device, and increased stability and thermal insulation, were also tentatively discussed.