Research Papers in Physics and Astronomy
Controlled formation of weakly bound atomic negative ions by electron transfer from state-selected Rydberg atoms
Date of this Version
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.
Published in Europhys. Lett., 40 (2), pp. 129-134 (1997). Copyright 1997 EDP Sciences. Used by permission.