QUANTAL CALCULATIONS FOR ALIGNMENT RELAXATION IN NE-ASTERISK(2P(5)3P)+HE COLLISIONS

The cross sections and rate coefficients for disalignment, depopulatio n, and alignment destruction of the 2p(2) and 2p(7) levels in the 2p(5 )3p configuration of Ne due to collisions with ground-state He are com puted in the framework of quantal close-coupling calculations. Good ag reement is obtained with the laser-induced fluorescence experiments fo r the temperature dependence of the disalignment rate in the 70-650 K range. ?be different behaviour of the disalignment cross section, whic h varies as T-0.62 for the 2p(2) level and T-0.195 for the 2p(7) level , is attributed to the importance of rotation effects in the first cas e, due to a more repulsive potential. Early measurements for the align ment destruction cross section are also reproduced by these theoretica l results.