Elastic rate coefficients for Li+H₂ collisions in the calibration of a cold-atom vacuum standard.

ABSTRACT: Ongoing efforts at the National Institute of Standards and Technology in creating a cold-atom vacuum standard device have prompted theoretical investigations of atom-molecule collision processes that characterize its operation. Such a device will operate as a primary standard for the ultrahigh-vacuum and extreme-high-vacuum regimes. This device operates by relating loss of ultracold lithium atoms from a conservative trap by collisions with ambient atoms and molecules to the background density and thus pressure through the ideal gas law. The predominant background constituent in these environments is molecular hydrogen H₂. We compute the relevant Li+H₂ Born-Oppenheimer potential energy surface, paying special attention to its uncertainty. Coupled-channel calculations a

SUBMITTER: Makrides C 

PROVIDER: S-EPMC7540224 | biostudies-literature | 2019 Apr

REPOSITORIES: biostudies-literature