Superconducting X-ray lithography 180 degrees bending dipole magnet design and material selection

The Superconducting X-ray Lithography Sources (SXLS) being built at Brookhaven National Laboratory requires two superconducting bending magnets. The selection of the material for the coldmass structure, i.e. the superstructure around the magnet coils, is most crucial because of its immense size and close proximity to the beam. The authors describe the selection process for the coldmass structure material in detail, and for the high strength structural bolts, the weld rods for the structural welds, and various components within the cryomagnetic system. Results of the verification testing are outlined. Nitronic 40 was the selected material for the coldmass structure. MP35N was used for making the compression bolts, aluminum 5083-0 for making the thermal shields, and AISI 316LN for making the room temperature vacuum vessel. In each case, a balance between performance and cost was carefully considered. The final design of the SXLS magnets was completed in February, 1992.<
>