Date of Award


Degree Name

Doctor of Philosophy



First Advisor

Dr. E. Y. Kamber

Second Advisor

Dr. N. Berrah

Third Advisor

Dr. T. Gorczyca

Fourth Advisor

Dr. D. Halderson


State-selective differential cross sections for single-electron capture processes in very slow collisions of Ar^q+ (q = 4 - 6) ions with Ne, and Ar^6+ ions with He have been studied experimentally at laboratory collision energies between 15 and 100 qeV, and at scattering angles between 0° and 8° by means of translational energy-gain spectroscopy technique. The translational energy spectra show that only a few final states are populated depending on the charge state of the projectile, the projectile laboratory scattering angle, and the collision energy. These measurements also show that the dominant reaction channels are due to capture into excited states of the projectile product Ar^(q-1)+. However, at very low energies, other channels due to transfer excitation processes are found to open at large scattering angles. The energy-gain spectra are interpreted qualitatively in terms o f the reaction windows, which are calculated using the single-crossing Landau-Zener model and the extended version of the classical over barrier model. The energy dependence o f cross sections for single-electron capture by Ar^q+ (q = 4 - 8) ions from He and Ne are also measured and found to be nearly independent o f collision energy, but increase with the projectile charge state. The data are also compared with other available measurements and theoretical calculations.


Fifth Advisor: Dr. P. Merati

Sixth Advisor: Dr. J. A. Tanis

Access Setting

Dissertation-Open Access

Included in

Physics Commons