Prototype superconducting magnet for the FFAG accelerator

A study of a superconducting magnet for the Fixed Field Alternating Gradient (FFAG) accelerator has been performed. The FFAG accelerator requires static magnetic field, and it is suitable for superconducting magnet applications, because problems associated with time varying magnetic field such as eddy current loss can be eliminated. The superconducting magnet, which can generate high magnetic field, is possible to realize a higher beam energy with a given accelerator size or the size to be smaller for a given beam energy. The FFAG accelerator magnet is demanded to have a complicated nonlinear magnetic field with high accuracy. As a first prototype superconducting coil, the coil configuration which consists of left-right asymmetric cross-section and large aperture has been designed. The prototype coil has been successfully developed by using a 6-axis Computer Numerical Control (CNC) winding machine. The magnetic field of the prototype coil has been demonstrated in warm measurement. As a consequence, the technical feasibility has been verified with the prototype coil development and the performance test. In addition, the technology components developed in the prototype coil have a possibility to transfer to a fusion magnet.