Scaling study for a high-field magnet for quasi-optical gyrotrons

The design of a 12 T superconducting magnet for a 280 GHz quasi-optical gyrotron is discussed. The gyrotron geometry requires a clear bore perpendicular to the magnetic axis through the center of the magnet, thus forcing the magnet to be formed of two separate sections. This causes the peak field on the windings to be over 14 T, and produces a double-peaked structure in the field. Calculations of mirror and cross bore RF heating and electron beam reflection as a function of the magnet and cross bore dimensions are presented, as are discussions of other tradeoffs in the magnet design. The conclusion of the study is that a suitable magnet is feasible