Autodetaching States of Cl

A number of peaks appear in the spectrum of electrons produced by collisions of ${\mathrm{Cl}}^{\ensuremath{-}}$ ions with helium- and hydrogen-gas targets. These features can be attributed to doubly excited autodetaching states of ${\mathrm{Cl}}^{\ensuremath{-}}$. Assignment of approximate electron configurations is possible for states appearing at 8.53, 9.15, and 9.97 eV, but ambiguities remain in the assignments for the other states lying between 10.47 and 12.44 eV.