Collision energy resolved Penning ionization electron spectra of polycyclic aromatic hydrocarbons

Abstract

Penning ionization of naphthalene and anthracene with He *(2 3S) atoms has been studied by means of simultaneous detection of collision energy and electron energy. The anisotropy of interaction potentials between He *(2 3S) atoms and the target molecules has been found on the basis of the collision energy dependences of partial Penning ionization cross-sections. Based on the analyses of collision energy dependences and electron correlation calculations, assignments of ultraviolet photoelectron spectra are discussed.