Carbon stripper foils used in the Los Alamos PSR

Carbon stripper foils produced by the modified controlled ACDC arc discharge method (mCADAD) at the Institute far Nuclear Study have been tested and used for high current 800-MeV beam production in the Proton Storage Ring (PSR) since 1993. Two foils approximately 110 μg/cm² each are sandwiched together to produce an equivalent 220 μg/cm² foil. The foil sandwich is supported by 4-5 μm diameter carbon fibers attached to an aluminum frame. These foils have survived as long as five months during PSR normal beam production of near 70 μA average current on target. Typical lifetimes of other foils vary from seven to fourteen days with lower on-target average current. Beam loss data also indicate that these foils have slower shrinkage rates than standard foils. Equipment has been assembled and used to produce foils by the mCADAD method at Los Alamos. These foils will be tested during 1997 operation