Zero kinetic energy proton and deuteron production from photoionization of H2 and D2

Abstract

A zero ion kinetic energy spectrometer has been developed to study the production of near zero energy protons and deuterons from dissociative photoionization of H2 and D2. Both H+ and D+ spectra show four peaks on top of a continuum. The continuum was found to be in excellent agreement with the single center Coulomb calculation for the direct dissociation through the X 2Σ+g state of H+2. The observed structures were shown to originate from autoionization of the doubly excited Q1 1Σ+g(1), Q1 1Σ+u(1), Q1 1Σ+u(2), and Q2 1Σ+u(1) states, of which the Q1 1Σ+g(1) state is dipole forbidden.