伝導冷却マグネットを指向したビスマス系ならびにイットリウム系高温超電導テープ導体の伝熱特性

Abstract

This paper reports thermal diffusivities of Bi-system and Y-system tape conductors. First, we measure temperature traces of the bundled conductors for the heater disturbance at conduction cooling conditions. Obtained results are modeled and analyzed using one-dimensional as well as two-dimensional heat balance equations. We show that the analysis results can successfully reproduce the experimental results for a wide temperature range from 20 to 77 K. On the basis of such results, we also clarify that the thermal diffusivity, in the perpendicular direction to the tape surface, of the Y-system conductors are five orders of magnitude lower than that of the Bi-system ones. Our results indicate that the consideration of such low thermal diffusivity is important for the conduction-cooled magnet design.