| Abstrakt: |
In order to provide an assessment of the "global" accuracy of the Liu-Siegbahn-Truhlar-Horowitz (LSTH) potential surface for H[sub 3], hot atom reaction yields, which are determined from collision processes over an energy range much wider than that of single-collision experiments, have been calculated for the Mu[sup *]+H[sub 2] and T[sup *]+H[sub 2] systems. The isotopic comparison of muonium (Mu=μ[sup +]e[sup -]), an ultralight isotope of hydrogen (m[sub Mu]/m[sub H]approx. 1/9), with the heaviest H-atom isotope, tritium, is a novel approach in testing the global accuracy of the H[sub 3] surface. These reaction yields have been calculated using a formalism developed for (μ[sup +]) charge exchange, with input cross sections for elastic, inelastic (rovibrational excitation) and reactive collisions determined from quasi classical trajectories on the LSTH surface, in the center-of-mass energy range 0.5-11 eV. The rate of energy loss of the hot atom (Mu* or T*) due to elastic and inelastic collisions with the moderator (H[sub 2]) drastically affects the hot atom reaction yield. In particular, the forwardness of the angular differential cross section for the elastic process plays a crucial role in determining the stopping power for hot atoms. Good agreement is obtained in the absolute yields for both Mu[sup *]+H[sub 2] and T[sup *]+H[sub 2], for the first time from microscopic cross sections, demonstrating that the LSTH surface remains surprisingly accurate over a wide range of energy and isotopic mass. © 2000 American Institute of Physics. [ABSTRACT FROM AUTHOR] |
