Numerical optimization of actively screened SC magnets coil geometries

This work is concerned with numerical optimization of actively screened SC magnets coil. An additional SC coil is suggested to shield stray fields. This SC coil only slightly increases the superconductor volume but drastically reduces the total magnet weight and its cost, and permits one to avoid such unpleasant features of the cold yoke as additional energy losses due to steel magnetization in a pulse mode and nonlinearities with steel saturation at high fields. We consider analytically the field of a shielded magnet and show how the volume of superconductor should be increased to get a complete active shielding. The design of SC coil geometries is performed by solving the optimization problem. Some results of actively screened dipole coil optimization are presented. 4 refs., 4 figs., 4 tabs