ROTATIONAL ENERGY-TRANSFER IN NO-AR SYSTEM AND THE VALIDITY OF THE PAIRWISE SUM OF THE POTENTIAL

Theoretical investigations of rotationally inelastic cross sections in NO-Ar system have been carried out. Cross sections predicted by the p airwise sum of che potential, V=V(N-Ar) + V(O-Ar) differs from the exp erimental cross sections by a factor of 3 or more if the pairwise inte raction term V(N-Ar) as well as V(O-Ar) is taken as spherically symmet ric Lennard Jones potential. The agreement, however, improves consider ably if the term V(N-Ar) as well as V(O-Ar) is made dependent on the o rientation of N-O bond. Such pairwise terms have been developed to obt ain theoretical results comparable with experiment. The cross section at an energy equal to average of Maxwell-Boltzmann distribution at a g iven temperature is nearly equal to the average cross section correspo nding to the same temperature. Further, the propensity for even transi tions and the effect of varying the mass of the inert gas atom are als o investigated.