Measurement of hyperfine structure and isotope shifts in the Dy 421-nm transition

Abstract

A measurement of the hyperfine coefficients and isotope shifts for the Dy I 421.291 nm transition [$4f^{10}6s^2(J=8)\to 4f^{10}6s6p(J=9)$] using atomic beam laser-induced fluorescence spectroscopy is presented. A King Plot analysis is performed to determine a specific mass shift of $\hat{I}´\hat{I}{½}_{sms}^{164-162}=11(7)$ Hz for the 421-nm transition, confirming the pure $4f^{10}6s6p$ configuration of the excited state. This transition is currently being explored for laser cooling of an atomic beam of dysprosium used in a search for a temporal variation of the fine-structure constant.

5 pages, 3 figures; typos corrected; references fixed; Dy magnetic moment corrected