Non-equilibrium convoy electron production in coincidence with outgoing projectile charge states

Abstract

The target thickness dependence of the convoy electron yield in carbon foils (3.1 < ϱx < 22 μg/cm²) from incident projectiles C^qi q_i=2, 4, 6 at 1 MeV/u has been measured in coincidence with the outgoing projectile charge states q_f. The observed charge state distributions of the carbon ions are in non-equilibrium for the thinnest targets. We find that the coincident convoy electron yield Y_e(q_f) in the non-equilbrium regime is dependent on ϱx, q_i and q_f. In contradiction to earlier findings, these results cannot be explained only by assuming electron loss to continuum processes (ELC). For the first time, the cusp-electron yield in the single collision system ³He⁺(0.2 < E_p/m < 0.33 MeV/u) on a He gas target in coincidence with the emergent projectiles ³He⁺ and ³He⁺⁺ has been measured. Surprisingly, a significant contribution of cusp electrons in coincidence with He+ has been found which is attributed to electron capture to continuum (ECC).