Magnetic Field Analysis of a Planar Superconducting Undulator with Variable Field Polarizations

A planar superconducting undulator (SCU), which generates horizontal and vertical fields, Bxand By, perpendicular to the beam directions, is inserted in between the magnetic poles of another unit, which generates the vertical field By. Analytical formulae of the magnetic fields are presented for the inserted, as well as the vertical-field, units. A scaling law may be applied to the SCU. The angle of the coil windings for the inserted unit is analyzed to maximize Bx. The range of the optimum rotation angle, for the range of gap/period ratio 0.1 – 0.6, is calculated to be 30° – 40°.