Radiative rotational lifetimes and state-resolved relative detachment cross sections from photodetachment thermometry of molecular anions in a cryogenic storage ring

Abstract

Photodetachment thermometry on a beam of OH${}^{-}$ in a cryogenic storage ring cooled to below 10 K is carried out using two-dimensional, frequency and time dependent photodetachment spectroscopy over 20 minutes of ion storage. In equilibrium with the low-level blackbody field, we find an effective radiative temperature near 15 K with about 90% of all ions in the rotational ground state. We measure the J = 1 natural lifetime (about 193 s) and determine the OH${}^{-}$ rotational transition dipole moment with 1.5% uncertainty. We also measure rotationally dependent relative near-threshold photodetachment cross sections for photodetachment thermometry.

arXiv commentManuscript LaTeX with 5 pages, 3 figures, and 1 table plus LaTeX supplement with 12 pages, 3 figures and 3 tables. This article has been accepted by Physical Review Letters

References in corpus (3)

• The Cryogenic Storage Ring CSR
• Internal state thermometry of cold trapped molecular anions
• CMISTARK: Python package for the Stark-effect calculation and symmetry classification of linear, symmetric and asymmetric top wavefunctions in dc electric fields

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