Electron gun design for high voltage piezoelectric accelerators

Abstract

Summary form only given. Piezoelectric transformers have been used to generate high voltage and are used to drive a compact electron accelerator in order to produce x-rays. Presented is an analysis of the electrostatic optics used to the increase maximum current density of the accelerator. Fowler-Nordheim analysis suggests that an electron beam produced by this accelerator reaches currents of 30 μA. This beam then impinges onto a high-z target where it is converted to x-rays via bremsstrahlung interactions. In order to maximize x-ray production, charged particle optics have been designed to focus the beam and increase current collected at the target. The target is then placed in the focus of the beam causing the number of incident electrons on its surface to increase as compared to the unfocused case. The electron beam is generated using a variety of cathodes on the output terminal of the piezoelectric transformer. A combination of finite-element simulations and experiments will be used to show how piezoelectric transformers perform as compact high-voltage electron beam accelerators and x-ray generators.