Controlled formation of weakly bound atomic negative ions by electron transfer from state-selected Rydberg atoms

Authors

M. Reicherts, Fachbereich Physik der Universität - Kaiserslautern, Germany
T. Roth, Fachbereich Physik der Universität - D-67653 Kaiserslautern, Germany
A. Gopalan, Fachbereich Physik der Universität - D-67653 Kaiserslautern, Germany
M.-W. Ruf, Fachbereich Physik der Universität - D-67653 Kaiserslautern, Germany
Harmut Hotop, Universität KaiserslauternFollow
C. Desfrançuois, Laboratoire de Physique des Lasers, Université Paris-Nord F-93430 Villetaneuse, France
Ilya I. Fabrikant, University of Nebraska-LincolnFollow

Date of this Version

10-15-1997

Comments

Published in Europhys. Lett., 40 (2), pp. 129-134 (1997). Copyright 1997 EDP Sciences. Used by permission.

Abstract

Using crossed atomic beams and mass spectrometric ion detection we have studied the formation of negative Ca ions in slow collisions between laser-excited state-selected Ne^**(ns; J = 2) and Ne^** (nd; J = 4) Rydberg atoms and ground state Ca atoms. The rate coefficients exhibit resonant behavior with maxima at an effective principal quantum number n^* of about 11.5 and an estimated peak value of about 10^-8 cm³ s^-1. Two different theoretical calculations, based on a curve-crossing model and on a modified adiabatic theory, respectively, yield n^*-dependences of the rate coefficients in good agreement with the experimental results.