基于冷原子的超高/极高真空测量机理研究进展

长期以来，随着原子的激光冷却和俘获技术的发展，利用超冷原子在磁阱中与背景气体碰撞的损失率以精确测量超高/极高真空度的新方法正在国内外深入研究，该方法将宏观物理量与微观参数相联系，可实现气体密度的精密测量和真空度的准确反演。然而，目前对于冷原子碰撞损失过程的非理想损失机制以及其它附加效应对测量过程的影响尚缺乏详细的分析，这些因素都制约着基于冷原子的超高/极高真空测量技术的发展。本文首先从冷原子的超高/极高真空测量基本原理出发，概述了冷原子真空度测量过程关键参数的不同确定方法和各自优缺点，随后，针对影响冷原子测量不确定度的各种附加损失，在相关研究基础上对其物理或数学模型进行分类讨论，分析为减小测量不确定度可采取的相应措施。最后，从关键参数的确定方法和其它测量过程的影响因素两方面，对冷原子超高/极高真空测量技术进行了总结和展望。

Research Progress of UHV/XHV Measurement Mechanism Based on Cold Atoms

With the development of laser-cooling and trapping technology of atoms, the new method of accurately measuring the ultra-high/extreme-high vacuum(UHV/XHV) is being studied in depth based on the loss-rate of ultra-cold atoms colliding with the background gas in the magnetic traps.This method connects the macroscopic physical quantities with microscopic parameters, and can realize precise measurement of gas density and accurate inversion of vacuum pressure.However, the detailed analysis of non-ideal loss mechanism of collisional loss process and some other additional effects on the measurement was lacked, which limited the progress of this technology.This paper summarized the determination methods of key parameters of vacuum pressure measurement process of cold atoms and then analyzed their advantages and disadvantages, in view of additional losses that affect the measurement uncertainty, the physical or mathematical models were classified and discussed on the basis of relevant research, and the corresponding measures that can be taken to reduce the measurement uncertainty were analyzed.Finally, the UHV/XHV measurement technology of cold atoms was summarized and prospected from the aspects of key parameters determination and the other additional losses analysis.