Positron and electron impact double ionization of argon: How 1st- and 2nd-order mechanisms influence the differential electron emission
Department of Physics, Missouri University of Science and Technology - Rolla, MO 65409 USA
2 Instituto de Física, Universidad Nacional Autónoma de México - Ap. Postal 20-364 01000, México DF, México
Accepted: 7 January 2010
Double-to-single–ionization ratios for electron emission as a function of the angle are measured for 200, 500, and 1000 eV positron and electron impact on argon. Both the sign of the projectile charge and the impact energy are shown to influence the angular dependences. By combining these ratios for positron and electron impact, information about how first- and second-order double-ionization mechanisms interfere and contribute to the total differential electron emission at different collision velocities is obtained.
PACS: 34.80.-i – Electron and positron scattering / 34.50.Fa – Electronic excitation and ionization of atoms (including beam-foil excitation and ionization) / 34.80.Dp – Atomic excitation and ionization
© EPLA, 2010