STABILIZED DOUBLE-ELECTRON CAPTURE IN NE10-HE COLLISIONS - VELOCITY DEPENDENCE OF RYDBERG-ELECTRON N,L-DISTRIBUTIONS()

The distribution over the n states populated by double-electron captur e in Ne10+-He collisions has been determined in the energy range of 0. 9-9 keV/u by analyzing the radiative decays of projectile Rydberg tran sitions. It has been found to be in fair agreement with predictions of the autotransfer-to-Rydberg-states model of Roncin et al. [J. Phys. B 26, 4181 (1993)]. Double-capture stabilization ratio R(S), defined as the ratio of true double capture sigma(TDC) to the sum of sigma(TDC) and autoionizing double capture sigma(ADC), has been studied at variou s energies. A slight enhancement of R(S) (35-50 %) and an increase by a factor of 5 of the cross sections for emission of optical transition s from (3,n) Rydberg states have been found as the projectile velocity decreases from 0.6 to 0.19 a.u. We propose a tentative explanation fo llowing a model of postcollisional satellization of Rydberg electrons.