VELOCITY DEPENDENCE OF TOTAL CHARGE-TRANSFER FROM STATE-SELECTED NA RYDBERG TARGETS

Relative measurements of total charge transfer in Na+ + Na(n(i)l) collisions at 30 to 2000 eV for selected s and d Rydberg states, n(i) = 22-41, are reported. The cross sections fall off with increasing reduced velocity (upsilon approximately = upsilon-ion/upsilon-e) more gradually than H+ + H(1s) capture below upsilon approximately = 1. The mean functional dependence agrees with classical trajectory Monte Carlo (CTMC) calculations, but previously unreported bumps occur at reduced velocities near 0.5 and 0.8. The validity of high-n CTMC calculations for low reduced velocity is discussed.