R&D activity of SAGBO avoidance for the CS insert fabrication

The fabrication of the Center Solenoid (CS) insert is under way in the Engi neering Design Activity (EDA) of International Thermonuclear Experimental R eactor (ITER), The purpose of the CS insert is to measure the performance o f Nb3Sn conductor for ITER. The R&D activities of the Strain Accelerated Gr ain Boundary Oxidation(SAGBO) avoidance was carried out for the CS insert f abrication. The shot peening and the flow control were established for the heat treatment of Nb3Sn processing. And the effect of the Chromium plating on the Nb3Sn strands was clarified by the several specimens.