Semi-classical and quantal calculation of state-to-state generalized cross-sections for N+2-He mixtures

Abstract

A semi-classical calculation of state-to-state generalized cross-sections has been performed for the first time and compared with quantal close-coupling calculations for the system N+ 2-He. At the total collision energy of 838.6cm-1, the semi-classical results for the cross-sections diagonal in the tensorial ranks agree with the close-coupling results within 20%, while those for the non-diagonal cross-sections give at least semi-quantitative agreement. It is expected that the agreement will improve when energy-averaged cross-sections are computed. At high collision energies, where large rotational quantum numbers are involved, quantal calculations cease to be feasible, and the semi-classical method provides a practical and reasonably accurate procedure to compute state-to-state cross-sections.