Effect of Direction of External Magnetic Field on Minimum Propagation Current of a Composite Conductor for LHD Helical Coils

The conductor for helical coils of the Large Helical Device consists a Rutherford-type NbTi/Cu cable, pure aluminum stabilizer, and copper sheath. dimensions stabilizer cross-sections are 18.0 mm × 12.5 12.4 5.2 mm, respectively. measured cold-end recovery current in magnetic field parallel to shorter side (B//12.5) is clearly lower than that longer (B//18.0) because difference magnetoresistance by Hall currents. Since minimum propagation Imp important determine upper limit operation current, has been two types one-turn coil samples, which were bent flatwise edgewise with inner radius 0.14 m extend length uniform background test facility. at B//12.5 almost same as B//18.0 spite large steady-state resistance. considered be determined heat balance before diffuses deeply into stabilizer.