Proton kinetic-energy distributions from dissociative photoionization of hydrogen

Abstract

Measurement of proton kinetic-energy distributions from dissociative photoionization of ${\mathrm{H}}_2$ is reported, for incident-photon energies up to 41 eV. Data are presented for transitions involving the $1s{\sigma }_g$ ground state and higher states of ${\mathrm{H}}_2^{+}$. At a photon energy of 41 eV, direct ionization involving the $2p{\sigma }_u$ state accounts for approximately one-half of the dissociative ionization; other processes, autoionization or direct ionization involving states of higher energy than $2p{\sigma }_u$, account for the remainder.