ANGULARLY RESOLVED ROTATIONAL ENERGY-TRANSFER IN HIGHLY VIBRATIONALLY EXCITED-STATES - NA2(V=31)-NE

The scattering of high vibrationally excited sodium molecules Na2(v = 31) with Ne atoms at 180 meV collision energy is investigated in a crossed molecular beam arrangement using laser optical methods. Angularly resolved rotationally inelastic and vibrationally elastic cross sections j(i) --> j(f) are measured for j(i) = 5, 7, and 9 less-than-or-equal-to j(f) less-than-or-equal-to 25. Pronounced rotational rainbow maxima are observed, the angular position of which indicates a significantly larger anisotropy of the interaction potential compared to that of Na2(v = 0)-Ne. Except for the increase of the anisotropy the vibrational excitation has little effect on the dynamics of rotational energy transfer. Good agreement with a new semiempirical Na2-Ne potential surface V(r,R,gamma) is found.