Date of Award


Degree Name

Master of Arts



First Advisor

Dr. E. Y. Kamber

Second Advisor

Dr. J. A. Tanis

Third Advisor

Dr. S. M Ferguson

Access Setting

Masters Thesis-Open Access


An experimental apparatus has been designed, enabling measurement of angular differential cross sections for single-electron capture (SEC). The design consists of a microchannel plate detector with a one-dimensional position sensitive anode. A bow-time shaped aperture was employed to convert a radially scattered distribution into an approximate linear one. An electrostatic retarding grid was used to separate SEC contributions from the reaction products. Measurements were made of the angular differential cross sections for SEC of Arq+ (q=4-6,8) ions scattering from He and Ar at impact energies of 600 to 3000 eV and angles between 0 and 23 mrad. The experimental angular spectra contain a main peak lying near a critical angle, Θc, the crossing radius of the active channel. The results for Ar6+ and Ar8+ on He and Ar are in qualitative agreement with calculations made using a semiclassical model based upon classical differential cross sections coupled with Landau-Zener transition probabilities.

Included in

Physics Commons