Coincidence Measurements of Electron Capture and Ionization in Low-EnergyAr+q+ (He, Ne, Ar, Xe) Collisions

Abstract

We have used a secondary ion recoil source to study electron capture and ionization in collisions of ${\mathrm{Ar}}^{+q}$ with He, Ne, Ar, and Xe at projectile energies between 250 and 660 eV per charge. By analyzing outgoing projectiles and target ions in coincidence we have measured cross sections for ionization of the system with and without simultaneous electron capture, as well as for normal electron capture only. Cross sections for direct ionization (no electron capture) are found to be small, whereas those for ionization accompanied by electron capture are often quite important.