PERFORMANCE OF Nb/Cu CLAD SEAMLESS SC CAVITY MADE FROM A PIPE BY HOT&COLD ROLLING AND DEEP-DRAWING
I. Itoh, Nippon Steel Co., 20-1 Shintomi Futtsu-shi, Chiba-ken, Japan
K.Saito, H.Inoue, KEK Accelerator Lab., 1-1 Oho Tsukuba-shi, Ibaraki-ken, Japan
W.Singer, DESY, 22603 Hamburg, Germany
Nippon Steel Co. has successfully developed Cu/Nb/Cu sandwiched seamless pipes for superconducting rf L-band cavities using deep-drawing and spinning of a Cu/Nb/Cu clad sheet which was fabricated by a hot rolling method. DESY formed single- cells with TESLA shape from the clad pipes using hydro- forming. KEK electron-beam welded Nb pipes on the cells and made surface treatments including barrel polishing, heat treatment and electropolishing. As a result of the vertical test, excellent performance : Eacc,max=39.0MV/m, Q0,max= 1.67×1010 at 1.5K and
1.3GHz was then achieved in the first test.