Reduction of trim coil power in superconducting cyclotrons by optimizing main coil geometry

In order to accelerate a variety of ions in a cyclotron, it is necessary to shape the magnetic field radially according to ion species and energy. In a superconducting cyclotron this is done by using various combinations of currents in two sets of coils along with a number of trim coils. The room temperature trim coils generate large power in the vicinity of low temperature. We have shown that by optimizing the coil geometries one can avoid using trim coils for correction of field and phase. Random search method and linear programming has been used for optimizing the coil geometries.