OBSERVATIONS AND SPECTRAL SIMULATIONS OF THE LI2(7)2(1)SIGMA(U)-]X(1)SIGMA(G)+ TRANSITION()

The Li-7(2)21SIGMA(u)+ --> X 1SIGMA(g)+ electronic transition has a bo und-bound and a bound-free part due to the double minimum nature of th e upper 2 1SIGMA(u)+ state. We have studied this transition both exper imentally and by performing spectral simulations. When inner well was excited the bound-free part at 4525 angstrom was observed due to the c ollisions between Li2 and argon. We found that when levels above the barrier are excited the bound-free emission is strongly affected by co llisional relaxation of Li2 by Li atoms. Conditions for the observati on of the bound-free part are discussed.