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Full-Text Articles in Physics
Ion Production And Mitigation In Dc High-Voltage Photo-Guns, Joshua T. Yoskowitz
Ion Production And Mitigation In Dc High-Voltage Photo-Guns, Joshua T. Yoskowitz
Physics Theses & Dissertations
One of the biggest obstacles to operating a GaAs polarized electron source with a long charge lifetime is the mitigation of ion back-bombardment. Several techniques exist to either clear ions from the accelerator or to mitigate ion damage of the photocathode. Predicting the effectiveness of these techniques requires sophisticated simulation models of electron impact ionization within the photo-gun. In this work, the effectiveness of applying a positive anode bias voltage to mitigate ion damage and increase the charge lifetime of the GaAs photocathode was studied over three run periods at the Continuous Electron Beam Accelerator Facility (CEBAF) at Jefferson Lab …
Investigation Of (E, 2e) Collisions And Related Phenomena, Jason Manuel Martinez
Investigation Of (E, 2e) Collisions And Related Phenomena, Jason Manuel Martinez
Physics Theses & Dissertations
In this thesis I investigate (e, 2e) processes, or electron impact ionization, using several theoretical methods. I first examine the problem using the Born approximations, particularly the Distorted Wave Born Approximation (DWBA), focusing on the underlying processes that dominate for ionization of the 2p state of Argon and Magnesium. I investigate as well the ionization of helium and hydrogen and use the simplicity of the approximation to probe the incident particle effects on the Helium cross section. In both cases the results are compared with experiment. I also produce cross section results for ions near threshold, a regime that …