Emittance compensation of superconducting gun and linac system for beams with large chromatic variance

Among the methods of emittance compensation for a superconducting rf gun and linac system include utilizing a solenoid and drift space after the gun to achieve a specific beam envelope with zero beam divergence before entrance into the linac. Studies on this method have assumed minimal energy spread in the beam. However, in cases where chromatic effects cannot be ignored this one solenoid emittance compensation technique is inadequate. Proposed is a new method of emittance compensation utilizing two solenoids in order to minimize emittance in beams with large energy spread. We present a theoretical basis for the new technique along with a computer optimized configuration. The results are compared with previous methods of emittance compensation.