GLOW-DISCHARGE PROCESSING VERSUS BAKEOUT FOR ALUMINUM STORAGE RING VACUUM CHAMBERS

Experiments were carried out on laboratory and prototype scale systems in order to establish the feasibility of argon discharge processing the PEP storage ring aluminum vacuum chambers. Electron-induced desorption rates showed significant reductions following bakeout and/or argon glow discharge treatment ( greater than 10**1**9 ions cm** minus **1). Data are presented and discussed in relation to advantages and problems associated with: water removal, argon trapping and subsequent release, electron energy dependence, discharge distribution, and surface plasma chemical effects.