Lithium [Li*(2 2P1/2,3/2)] fine structure transitions induced by collisions with noble gas atoms

Abstract

Dye laser excitation and interferometric fluorescence analysis techniques were used to determine collision induced fine structure transition rate coefficients in the Li*(2 2PJ)+ He, Ne, Ar, Kr, and Xe systems at a temperature of 555.7 K. All the noble gases induce transitions at ’’gas kinetic’’ rates, but differences in the individual magnitudes of the rate coefficients are probably sensitive to the long range portions of the Li*(2 2PJ)–noble gas interaction potentials. There is no appreciable isotope effect for 6Li*/7Li*+He, Ne, Ar systems. Simple models based upon localized transition concepts do not agree adequately with experimental results, suggesting that full dynamical computations using quantal and/or refined semiclassical formalisms are probably required for proper treatment of the Li*(2 2PJ)–noble gas systems and for stringent tests of various choices for the interaction potentials.