Subshell contributions to electron capture into the continuum in MeV/u collisions of deuterons with multielectron targets

The process of the capture of a target electron into the projectile continuum (ECC) is investigated both experimentally and theoretically for collisions of 1.25-6.00 MeV deuterons with multielectron gas targets. Double-differential cross sections (DDCS), d(2)sigma/d Omega dE, of the ECC cusp-shaped electron peak involving He, Ne, and Ar gas targets were measured at the emission angle of zero degrees with respect to the ion-beam velocity. Corresponding DDCS calculations, obtained using continuum distorted-wave (CDW) and continuum distorted-wave eikonal initial-state (CDW-EIS) theories, were critically compared to the measurements. The role of each atomic subshell of the multielectron Ne and Ar targets is examined employing the CDW-EIS theory with numerical target wave functions, which is found to best agree with the measurements.