AVS 63rd International Symposium & Exhibition
    Vacuum Technology Tuesday Sessions
       Session VT-TuM

Paper VT-TuM11
Simulated and Measured Extreme High Vacuum in the Jefferson Lab Polarized Electron Source

Tuesday, November 8, 2016, 11:20 am, Room 104C

Session: Vacuum Pumping and Material Outgassing
Presenter: Marcy Stutzman, Thomas Jefferson National Accelerator Facility
Correspondent: Click to Email

The polarized electron source for the Jefferson Lab CEBAF nuclear physics program has stringent vacuum requirements for successful operation. Research projects aimed at improving the static vacuum into the extreme high vacuum range, below 10-12 Torr, have investigated outgassing rate reduction through coatings and heat treatments, vacuum characterization optimizing the utilization of commercial extreme high vacuum gauges, and pumping configurations including developments in UHV/XHV cryopumping. Additionally, limitation of dynamic vacuum during operation has been studied using surface analysis and processing toward reducing field emission from the high voltage electrode in the electron source. Both modeling and experimental results of these studies and the impact of incorporating these improvements in the vacuum system for the Jefferson Lab polarized electron source will be presented.