Vacuum Characterization and Improvement for the Jefferson Lab Polarized Electron Source

Operating the JLab polarized electron source with high reliability and long lifetime requires vacuum near the XHV level (<=1x10-12 Torr). This paper describes ongoing vacuum research at Jefferson Lab including characterization of outgassing rates for surface coatings and heat treatments, ultimate pressure measurements, investigation of pumping including an XHV cryopump, and characterization of ionization gauges in this pressure regime.