SYMMETRY AND ENERGY DEPENDENCE OF ROTATIONAL TRANSFERS BY COLLISIONS OF DIATOMIC HYDRIDE EXCITED STATES

Abstract
A rotational level Ji is selectively excited by a tunable laser. Collision cross-sections are measured for energy transfers from Ji to any Jf level. In extensive previous work, the Ji→Jf cross-sections for wide J variation in ¹Σ states have been compacted using fitting laws with 2 or 3 adjustable parameters (1). These parameters depend implicitely on the interaction potential which have not yet been calculated in excited states. Our rotational transfer experiments, in series of metal hydride excited states colliding with He or Ar, allows us to illustrate the meaning of general fitting laws. Two examples are considered : - ¹Σ state, where J is purely rotational angular momentum. - ¹&Pi state coupling case (a), with electronic structure.