Energy transfer in ion-Rydberg-atom charge exchange

Charge-transfer collisions between slow multiply charged ions and highly excited Rydberg atoms have been studied to determine the details of the internal energy transfer accompanying charge exchange. The experiment uses lasers to define uniquely the binding energies of both initial and final states of the collision, thereby eliminating the ambiguity inherent in the selective field ionization method used for previous studies. The results clearly characterize the capture energetics over the range of ion charge q = 1 - 11 and velocity v = 0.031-0.138 a.u. Thr measurements are in very good agreement with predictions of the classical trajectory Monte Carlo method, but not with predictions of other classical models.