DESIGN AND ANALYSIS OF A 25T RESISTIVE NMR MAGNET

A 25 Tesla resistive magnet with homogeneity of 1 ppm over 10 mm diame ter spherical volume is being designed at the National High Magnetic F ield Laboratory in Tallahassee, FL, The magnet consists of three conce ntric axially cooled Bitter stacks connected electrically in series, I t will produce a peak field of 24.1 T in a 50 mm warm bore while consu ming 15 megawatts of power and 25 T at 16.3 MW. Each of the stacks is designed to have a high uniformity by itself so the tolerance in axial positioning is not critical. Details of the magnet design, sensitivit y to manufacturing tolerances and current distribution between cooling rings is presented.