Laser spectroscopy of light Yb isotopes on-line in a cooled gas cell

Abstract

A gas-filled, liquid-nitrogen-cooled cell on-line with an accelerator permits fluorescence spectroscopy of atoms of heavy-ion reaction products generated at rates less than ${10}^{3}$ ${\mathrm{s}}^{\mathrm{\ensuremath{-}}1}$. This low required rate of production allows the optical spectroscopy of radioactive atoms to be extended further from stability. With the cell we have measured isotope shifts of $^{152,154,156,158,166}\mathrm{Yb}$, reaching N=82, four nuclides further than previously reached with other techniques. The change in rms charge radius near the shell closure is surprisingly large.