Magnetic design of a superconducting AGS snake

Brookhaven National Laboratory plans to build a partial helical snake for polarized proton acceleration in the AGS. It will be a 3 Tesla superconducting magnet having a magnetic length of 1.9 meter. AGS needs only one magnet and currently there is no plan to build a prototype. Therefore, the first magnet itself must function at the design operating field and provide the required field quality, spin rotation and deflections on the particle beam. New software have been developed that exchanges input/output between the OPERA3d field design program, the Pro-Engineering CAD model and the software that drives the machine to make slots in aluminum cylinders where blocks of 6-around-1 NbTi wires are placed. This new software have been used to carry out a number of iterations to satisfy various design requirements and to assure that the profile that is used in making field computations is the same that is used in cutting metal. The optimized coil cross-section is based on a two-layer design with both inner and outer layers having five current blocks per quadrant. The ends are based on a design concept that will be used for the first time in accelerator magnets.