Photodetachment Spectroscopy of the $S_{2}^{-}$ Anion

Numerous experiments have investigated the properties and dynamics of single-atom negative ions. Similar experiments may also be conducted with molecular anions. Laser photodetachment spectroscopy of such ions is more complex due to rotational and vibrational structure, but often yields spectroscopic benchmarks such as rotational constants and vibrational energies. We have conducted low-resolution photodetachment spectroscopy of the $S_{2}^{-}$ anion over a range of roughly 2000 $cm^{-1}$. The ions are created in a Penning ion trap by a two-step dissociative attachment process. The photodetachment is achieved with a tunable titanium:sapphire laser. Our results are consistent with a model adapted from previous studies of single-atom photodetachment, and also show evidence of successful evaporative cooling of the ion cloud. Future experiments will focus on high-resolution detachment spectroscopy of these and other ions with an eye toward measurement of their molecular constants.