Excitation and ionisation resulting from electron capture in Ar6+ + H2 collisions at ion projectile energies of 200-1200 keV

Photon emission between 20 and 250 nm, and slow electron and ion production cross sections have been measured for collisions between Ar6+ and H2 at impact energies from 200 to 1200 keV. These studies indicate that single electron charge transfer into excited states of the product ion is the most important inelastic process. The capture occurs mainly into n = 4 levels with the excitation of the higher angular momentum states dominating over most of the projectile energy range. Slow electrons are apparently produced primarily by the capture ionisation process in which the projectile captures an electron and an additional electron is emitted from the target. The capture ionisation cross section is appreciable, amounting to 30 to 40% of the total excitation cross section. (author)