DEVELOPMENT OF SUPERCONDUCTORS FOR THE MAGNETIC SYSTEM OF THE INTERNATIONAL THERMONUCLEAR EXPERIMENTAL REACTOR (ITER) IN RUSSIA

摘要

The modern state of research on the development and production in Russia of superconductors based on Nb_3Sn and Nb-Ti and intended for the model coil and the actual magnetic system of the International Thermonuclear Experimental Reactor (ITER) is reviewed. It is shown that Nb_3Sn-based superconductors and manufactured according to the "bronze" technology for insertion of a model coil of the central solenoid meets the requirements of the ITER. The critical current density in cross section without copper is at least 550 A/mm~2 in a 12 T field at T = 4.2 K, the level of hysteresis losses does not exceed 200 mJ/cm~3, and the copper stabilizing envelope of the chromium-plated superconductor has a resistance ratio of 150. Results are presented from the development and testing of Nb_3Sn-based superconductors with internal source of tin that confirm the possibility of using this material for the coils of the magnetic system. The properties of Nb-Ti-based superconductors for the toroidal-field coil are reviewed. It is shown that it is theoretically possible to produce such Nb_3Sn- and Nb-Ti-based semiconductors using large composite billets 300 mm in diameter. This opens the way towards the creation of large-scale production of these materials for the magnetic system of the International Thermonuclear Experimental Reactor at a rate of up to several dozen tons annually.