Electron loss to the continuum for H2+ and He+ ions colliding with H2, He, Ne and Ar

Absolute cross sections for electron loss to the continuum have been obtained for 0.8-2.8 MeV H+2 and He+ ions incident on H2, He, Ne and Ar gases. The target consisted of a jet of gas from a multicapillary array. A 300 parallel-plate analyser was used to study the energy spectra of the ejected electrons as detected in a cone of solid angle 1.56 x 10-3 sr about the forward direction. The cross sections were obtained by numerically integrating the ejected-electron velocity spectra over a width of 0.25 au on either side of the centre of the cusp-shaped peak. When defined in this way the cross sections are found to decrease slowly with increasing projectile velocity, in agreement with an available theoretical calculation and other experimental results. (author)