THE ROLES OF ELECTRONIC AND NUCLEAR STOPPING IN THE DESORPTION VALINE NEGATIVE MOLECULAR IONS

J.E. HUNT; M. SALEHPOUR; D.L. FISHEL; J.C. TOU

doi:doi:10.1051/jphyscol:1989205

Numéro		J. Phys. Colloques Volume 50, Numéro C2, Février 1989 Second International Workshop on MeV and keV Ions and Cluster Interactions with Surfaces and Materials


Page(s)		C2-27 - C2-31
DOI		https://doi.org/10.1051/jphyscol:1989205

Second International Workshop on MeV and keV Ions and Cluster Interactions with Surfaces and Materials

J. Phys. Colloques 50 (1989) C2-27-C2-31
DOI: 10.1051/jphyscol:1989205

THE ROLES OF ELECTRONIC AND NUCLEAR STOPPING IN THE DESORPTION VALINE NEGATIVE MOLECULAR IONS

J.E. HUNT¹, M. SALEHPOUR¹, D.L. FISHEL^{1, 2} and J.C. TOU^{1, 3}

¹ Argonne National Laboratory, Chemistry Division, 9700 South Cass Avenue, Argonne, IL 60439, U.S.A.
² Kent State University, Chemistry Department, Kent, OH 44242, U.S.A.
³ Dow Chemical U.S.A., Midland, MI 48667, U.S.A.

Résumé
Le rendement des ions moléculaires négatifs de valine a été mesuré en fonction de la vitesse des ions primaires Ar⁺, Kr⁺, Xe⁺. Les pouvoirs d'arrêt électronique et nucléaire ont des valeurs comparables mais des variations inversées dans la région de vitesse considérée. Les rendements sont expliqués en terme de pouvoir d'arrêt électronique seulement, sans contribution du pouvoir d'arrêt nucléaire.

Abstract
The yield of valine negative molecular ions has been measured as a function of Xe⁺, Kr⁺, and Ar⁺ primary ion velocity. The electronic and nuclear stopping powers are comparable in magnitude and opposite in slope in the experimental velocity region. The yield data are explained in terms of electronic stopping power alone, with no contribution from nuclear stopping power within the experimental error. Low molecular weight atomic species are found to be best described by a nuclear stopping power related process.