A semiclassical time-dependent Hartree model calculation of capture and multiple ionization in heavy ion-Ar collisions

We consider the problem of correlated charge state cross sections in collisions of highly charged heavy ions (projectile charge qP>20) with argon atoms. The Vlasov model, which describes the outer 16 electrons with one single-particle distribution, gave reasonable results for direct ionization. For the capture + multiple ionization channels it yields distributions over recoil charges qrec that are wider than those observed by experiment and are shifted towards higher values of qrec. Better results are obtained from an (h = 0)-model calculation in which separate distribution functions are used for the Ar (L)- and (M)-shells respectively. The experimental data are found to be consistent with a statistical evaluation using a single trinomial distribution. It appears, however, that in order to obtain the required single-particle capture and ionization probabilities one should work at least at the level of a semiclassical shell model. (orig.)