Angular differential energy gain measurements of highly charged ion-atom collisions at 100 and 120 eV/q

Angular differential energy gain spectra of C4+ and N4+-He collisions have been measured at the collision energy of 100 and 120 eV/q, respectively. In the case of C4+-He collisions, the oscillation structure in the angular differential cross section of the double-electron capture into the C2+(1s22s21S) state has been clearly observed. On the other hand, in the case of N4+-He collisions, the N3+(1s22p21S) product channel in single-electron capture process is dominant at the forward scattering angle and the N3+(1s22p21D and/or 3P) state becomes dominant at larger scattering angle