Laser optogalvanic photodetachment spectroscopy: A new technique for studying photodetachment thresholds with application to I−

Abstract

Electron photodetachment from I⁻ ions has been observed using an optogalvanic technique in which an electrical discharge in iodine vapor was probed with a pulsed dye laser. The first photodetachment threshold, corresponding to the onset of production of I(²P_3/2) atoms, was located at 405.18±0.02 nm giving for the electron affinity E_a(I) =3.0591±0.0001 eV.