Superconducting coil design for Large Helical Device

The superconducting coil design for the Large Helical Device, an interuniversity magnetic confined fusion research device, is described. The major and minor radii of the helical coil are 3.9 m and 0.975 m, respectively. The helical coil is made of a pool-cooled conductor, and the field experienced by the conductor is 7.2 T at phase I and 9.6 T at phase II. Three pairs of poloidal coils are also superconducting. The coils will be made of NbTi conductor.