Low Energy Electron Gun Power Control Unit

Chad Fish, Utah State University


Orbiting spacecraft are subject to surface charging induced by plasma currents. The reaction of spacecraft materials to electron and ion bombardments is a major factor in spacecraft surface charging. A key bombardment process known to induce severe spacecraft surface charging is secondary electron emission. NASA funds the Surface Science Group in the Physics Department at Utah State University to research and document different secondary electron emission material characteristics. The Surface Science Group utilizes electron gun systems to create and observe secondary electron emissions environments. An integral component of the electron gun system is an energy control unit responsible for fueling the electrons focused into a beam by the electron gun. I was employed by the Surface Science Group to design and implement a low energy control unit covering a 0-4 keV electrical spectrum. My design and implementation were based on a unipotential electron gun system; the results and details are set forth in the following technical report.