Spectroscopy of electric dipole and quadrupole transitions in ${}^{224}$Ra${}^{+}$

Abstract

We report on spectroscopy of the low-lying electronic transitions in ${}^{224}$Ra${}^{+}$. The ion's low charge to mass ratio and convenient wavelengths make ${}^{224}$Ra${}^{+}$ a promising optical clock candidate. We measured the frequencies of the the ${}^2{S}_{1/2}$$\leftrightarrow$${}^2{P}_{1/2}$ cooling transition, the ${}^2{S}_{1/2}$$\leftrightarrow$${}^2{D}_{5/2}$ clock transition, the ${}^2{D}_{3/2}$$\leftrightarrow$${}^2{P}_{3/2}$ electric dipole transition, and the ${}^2{D}_{5/2}$$\leftrightarrow$${}^2{P}_{3/2}$ cleanout transition. From these measurements we calculate the frequencies of the ${}^2{D}_{3/2}$$\leftrightarrow$${}^2{P}_{1/2}$ repump transition, the ${}^2{S}_{1/2}$$\leftrightarrow$${}^2{D}_{3/2}$ electric quadrupole transition, and the ${}^2{S}_{1/2}$$\leftrightarrow$${}^2{P}_{3/2}$ electric dipole transition.

5 pages, 8 figures