量子真空标准研究进展

Development of Quantum Vacuum Standard

2018年,国际计量局将对国际单位制7个基本量进行重新定义或重述。基于光学方法的真空计量新方法、新概念进一步发展,促进真空计量标准向量子化迈进,对真空基本量复现以及今后真空国际单位制的重新定义(由压力的SI单位帕斯卡(Pa)向气体密度单位(mol/m^3或分子个数/m^3,变化)具有重要意义。与传统计量技术相比,利用光学方法所建立的量子真空计量标准具有不需要自校、溯源链零长度、响应快、准确度高、可在多个地点及不同时间复现等优点,为真正意义上的绝对原级标准。本文介绍了美国国家标准与技术研究院(NIST)、德国联邦物理技术研究院(PTB)及瑞典国家测试和检定研究院(SNTRI)等机构开展的基于折射率、吸收光谱、冷原子3种光学方法的新一代量子真空计量标准研究进展,对原理、关键技术及难度挑战进行了阐述和分析。

In 2018, there will be a major revision of the International System of Units (SI) which will result in all ofthe seven base units being defined or reworded by fixing the values of certain atomic or fundamental constants. The futureof vacuum metrology will rely on quantum-based primary standard based on optical methods which represents a disruptivechange in the way of realizing and disseminating the SI unit of pressure, the pascal. Compared to conventional standards,these new quantum-based vacuum primary standards will potentially enable zero-chain SI traceability, fast response time,high accuracy and unrestricted circumstance. The research and development of quantum-based primary vacuum standardlaunched by NIST, PTB and SNTRI in the field of vacuum metrology are reviewed. The paper reviews the theoretical andexperimental foundations and key technologies of three methods, including refractive index method, absorption method andrate of cold atom loss method.