Eckel Stephen, Barker Daniel S, Fedchak James A, Klimov Nikolai N, Norrgard Eric, Scherschligt Julia, Makrides Constantinos, Tiesinga Eite
Sensor Sciences Division, National Institute of Standards and Technology, Gaithersburg, MD 20899, USA.
Joint Quantum Institute, National Institute of Standards and Technology and University of Maryland, Gaithersburg, MD 20899, USA.
Metrologia. 2018;55. doi: 10.1088/1681-7575/aadbe4.
Cold atoms are excellent metrological tools; they currently realize SI time and, soon, SI pressure in the ultra-high (UHV) and extreme high vacuum (XHV) regimes. The development of primary, vacuum metrology based on cold atoms currently falls under the purview of national metrology institutes. Under the emerging paradigm of the "quantum-SI", these technologies become deployable (relatively easy-to-use sensors that integrate with other vacuum chambers), providing a primary realization of the pascal in the UHV and XHV for the end-user. Here, we discuss the challenges that this goal presents. We investigate, for two different modes of operation, the expected corrections to the ideal cold-atom vacuum gauge and estimate the associated uncertainties. Finally, we discuss the appropriate choice of sensor atom, the light Li atom rather than the heavier Rb.
冷原子是出色的计量工具；目前它们实现了国际单位制（SI）时间，并且很快将在超高真空（UHV）和极高真空（XHV）环境中实现SI压力。基于冷原子的真空计量一级标准的开发目前属于国家计量机构的职责范围。在“量子-SI”这一新兴范式下，这些技术变得可部署（即与其他真空腔室集成的相对易于使用的传感器），为终端用户在超高真空和极高真空环境中提供了帕斯卡的一级标准实现。在此，我们讨论这一目标所带来的挑战。我们针对两种不同的运行模式，研究了对理想冷原子真空计的预期修正，并估算了相关的不确定度。最后，我们讨论了传感器原子的合适选择，即轻锂原子而非较重的铷原子。
