No abstract

On étudie l'influence sur la section efficace de l'anisotropie du potentiel d'interaction. On introduit une méthode de résolution approchée de l'équation d'évolution, valable pour un niveau J = 1. On montre qu'il est nécessaire de tenir compte de l'anisotropie pour déterminer correctement le potentiel à l'état excité à partir des données expérimentales

Initial rotational distributions of the vibrationless HgH or HgD molecules produced in the exoergic reactions of Hg (3P1) with H2, D2, and HD have been determined. No isotope effects have been observed. In the case of the reaction with HD the ratio [HgH(v″=0)]/[HgD (v″=0)] as well as the summed over all v″ ratio [HgH]/[HgD] have been measured.

Absolute rate constants for quenching and intramultiplet mixing of Hg(63P0,1,2) by collisions with H2, HD, and D2 have been determined. A smooth variation of these coefficients with the isotopic form of hydrogen has been observed. For He only an upper limit of the rate constants has been obtained. Attempts to explain the 3P1←3P2 transfer by simple mechanisms are described. The surface crossing mechanism seems the most adapted. But a theory more elaborate than the one presented here should be developed, including both the rotational and the vibrational degrees of freedom of the molecule.