Design, Fabrication, and Test of a Superconducting Dipole Magnet Based on Tilted Solenoids

It can be shown that, by superposing two solenoid like thin windings that are oppositely skewed (tilted) with respect to the bore axis, the combined current density on the surface is "cos-theta" like and the resulting magnetic held in the bore is a pure dipole. As a proof of principle, such a magnet was designed, built and tested as part of a summer undergraduate intern project. The measured field in the 25 mm bore, 4 single strand layers using NbTi superconductor, exceeded 1 T. The simplicity of this high field quality design, void of typical wedges end-spacers and coil assembly, is especially suitable for insert-coils using High Temperature Superconducting wire as well as for low cost superconducting accelerator magnets for High Energy Physics. Details of the design, construction and test are reported.