Demonstration of a High-Field Short-Period Undulator Using Bulk High-Temperature Superconductor

The first ever practical-level field generation for an undulator consisting of bulk high-temperature superconductors is reported and described. A high-field short-period undulator enables bright hard X-ray to be obtained in moderate-energy synchrotrons and to provide a polarized MeV gamma-ray source for producing a polarized positron beam via pair production in future linear colliders. To generate sinusoidal magnetic fields using bulk high-temperature superconductors, a novel structure has been developed in which the superconductors line up in a staggered configuration inside a solenoid. An undulator field of 0.85 T is achieved using a 10 mm period, 4 mm gap prototype in a 2 T solenoid.