A 10 T cryo-cooled superconducting magnet with 100 mm room temperature bore

Abstract A cryo-cooled NbTi/Nb 3 Sn superconducting magnet has been fabricated. It generated 10T field in the center of a 100 mm room temperature bore. A 4K GM refrigerator, using Er 3 Ni regenerator material, cooled the magnet without help of liquid helium. Heat generated in coils is removed through the heat conduction copper cylinder attached on the outer wall of each coil. Bi(2212) superconducting current leads are adopted to reduce heat leakage into the 4K stage. Two diodes shunt circuits were set into the cryostat to protect the coils. Fast ramp, 8T energization within 15 min, was attained by controlling the hysteresis loss for the Nb 3 Sn conductor.