Ionization processes in slow collisions of heavy particles. I. He and Ne⁺on Ne, Ar, Kr, and Xe

Apparatus for the investigation of ionizing collisions of heavy particles by electron spectroscopy is described. Collisions of He + and He on Ne, Ar, Kr, and Xe are studied in the kinetic energy range from 100 eV-5000eV by measurement of energy spectra and angular distributions of the ejected electrons. As in collisions at higher energies, the spectra are composed of discrete peaks arising from autoionizations of the separated particles, and a continuous part. This latter part is much more pronounced for collisions with He + . A mechanism for the production of the continuous part is proposed, which explains this fact. The angular distributions of electrons of discrete energies (peaks) are found to be nonisotropic in some cases, and dependent on the collision energy. In one case the distribution is asymmetrical with respect to theta = pi /2 (angle measured from beam direction).