We have performed systematic quantitative measurements of the critical current density Jc(B, T) for YBCO thin films proton-irradiated to various dosages using the MOI technique. Results for external magnetic fields up to 400Oe and temperature ranging from 5 to 80K are presented for a 600nm thick YBCO film irradiated by proton up to a dosage of 1016 cm -2 at 500 keV. While no significant differences were observed for T>50K, the Jc values consistently increased with the increasing external field for T<50K.
Multipactoring suppression by fine grooving of conductor surfaces of coaxial-line input couplers for high beam current storage rings