STABILITY OF COMPOSITE TAPE SUPERCONDUCTORS AGAINST TRANSIENT THERMAL DISTURBANCES.

THE TAPE CONDUCTOR COMPOSED OF NIOBIUM-TIN AND COPPER CAN CARRY AN OVERALL CURRENT DENSITY IN EXCESS OF 300 A/MM2 IN A MAGNETIC FIELD OF 10 T. THE INFLUENCE OF TRANSIENT THERMAL DISTURBANCES ON ITS STABILITY HAS BEEN THEORETICALLY ANA TWO DISTINCT PROCESSES CHARACTERIZE THE RECOVERY OF A TRANSIENT TEMPERATURE RISE. ONE IS THE COOL-DOWN OF COPPER DUE TO HEAT TRANSFER TO THE COOLANT AND THE OTHER IS CONTROLLED BY THERMAL DIFFUSION IN NIOBIUM-TIN. THESE 2 PROCESSES LEAD TO THE CONDITIONS REQUIRED FOR STABILITY PROVIDED THAT DISTURBANCES ARE OF A TRANSIENT DISTRIBUTED NATURE. THESE CONDITIONS ARE EQUIVALENT TO A SINGLE CRITERION OF THE MAGNETIC STABILITY.