Development of a large bore superconducting magnet with narrow liquid helium channels

A large bore NbTi superconducting magnet is designed, manufactured and tested. The superconducting magnet has an inner diameter of 460 mm, outer diameter of 600 mm and height of 540 mm. The magnet is dry wound using rectangular and round superconducting wires with their dimensions of 1.3 times 2.0 mm and Oslash1.3 mm respectively. In order to improve helium cooling effect, narrow liquid helium channels are set between adjacent layers. The magnet can generate 4 T central magnetic field at the designed operating current of 305 A. The magnet has been tested in a compact cryostat. Experimental results show that the superconducting magnet reached the designed magnetic performance. Details of the magnet design, fabrication and test are described in this paper