Vacuum joints of dispersion-strengthened copper and its applications in synchrotron radiation front end

Abstract

Masks are critical elements of synchrotron radiation front end that are exposed to high temperature and stress. The absorber material is typically comprised of dispersion-strengthened copper, which can retain high performance at elevated temperature. Joining processes under vacuum, including brazing and electron beam welding, are novel approaches for prolonging the absorber and for reducing power densities. The mechanical properties of brazed joints and electron beam welded joints of dispersion-strengthened copper workpieces are evaluated by tensile testing at 20, 100, and 200 °C. The testing results indicate that the tensile strength and elongation of both vacuum joints decrease with increasing temperature. Compared to brazed joints, electron beam welded joints have higher tensile strength, better ductility, and more stable performance. A novel welded mask with a total length of 600 mm is presented and shown to be practical for use in the highest heat load front end in the Shanghai synchrotron radiation facility phase-II beamline project.