A Comparison of Outgassing Measurements For Three Vacuum Chamber Materials P. Adderley, M. Baylac, J. Clark, T. Day, J. Grames, J. Hansknecht, G. Myneni, M. Poelker, P.M. Rutt†, C.K. Sinclair*, M.L. Stutzman Thomas Jefferson National Accelerator Facility 12000 Jefferson Ave., Newport News, VA 23606 USA. Operated by SURA for the DOE Abstract Chambers Method Pros and Cons Measured Outgassing Rates Aluminum 304 SS 316L SS Data Outgassing Rate Methods Test Chamber Orifice Extractors Spinning Rotor Orifice Production Photoguns Gun Vacuum Chamber Conclusions System Schematic 0.082” Orifice Rate of Rise †Now at Helix Technology, Prutt@helixtechnology.com *Now at Cornell University, cks26@cornell.edu, § Aluminum Chamber by Atlas Technologies, www.atlasbimetal.com