Subshell differential cross sections for electron transfer in collisions of U90+ ions with gaseous targets

Balmer spectra produced in collisions between He-like uranium projectiles a nd gaseous targets (N-2, Ar, Kr, and Xe) were measured at the jet-target ar ea of the ESR storage ring. The X-ray radiation were recorded in coincidenc e with the down charged projectiles having captured one electron from the t arget atom. By means of spectra simulation, all the significant Balmer tran sition lines were identified. Further, the j-differential cross sections fo r electron capture into projectile subshells were deduced from the well res olved spectra. For the heavier targets, where NRC contributes considerably, systematic deviations between experiment and the continuum distorted wave approximation are observed.