33rd International Field Emission Symposium / 33ème Symposium International d'Emission de Champ
J. Phys. Colloques 47 (1986) C7-81-C7-86
DOI: 10.1051/jphyscol:1986715
FIELD DISSOCIATION BY ATOMIC TUNNELING OF COMPOUND IONS : ISOTOPE AND ORIENTATIONAL EFFECTS
T.T. TSONGPhysics Department, The Pennsylvania State University, University Park, PA 16802, U.S.A.
Abstract
Dissociation of HeRh2+ in high electric field occurs by tunneling of a neutral He out of the ion. This tunneling process occurs most readily when it is rotated 180° from its desorbed orientation. This rotation time is measured to be 790±21 fs. The tunneling effect is supported by a very strong isotope effect observed when 4He is replaced by 3He, and also by a WKB calculation of barrier penetration probabilities.