Close-coupled calculation of self-broadening of helium triplet lines

A quantum close-coupled calculation of the collisional self-broadening of helium triplet lines based on the quantum-mechanical impact theory of Baranger is presented in which the interatomic interaction is represented by adiabatic molecular potentials calculated using model potentials for the electron-atom and atomic core-core interactions. The close-coupled equations are solved using a R-matrix method and results obtained for the lines 2 3 S 1 -3 3 P 2,1,0 , 2 3 P 2,1,0 -n 3 S 1 and 2 3 P 2,1,0 -n 3 D 3,2,1 for n=3,4,5 at temperatures of 80 and 300 K. These quantum results are compared with those obtained using the semiclassical model with and without a cutoff on collision impact parameters to exclude perturber paths which would enter classically forbidden regions.