Kyoto University, Kyoto, Japan
High-field short-period undulator will be one of the key technologies for the future light sources. Various approaches have been continued under the limitation of materials for permanent/superconducting magnets. A use of bulk superconductor is attractive for its high current density under existence of high magnetic field. The critical current density for rare-earth barium copper oxide (REBCO) bulk superconductor exceeds 10 kA/mm2 even at 10 K in a field range below about 3 T and exceeds 20 kA/mm2 at 4.2 K. In order to utilize the quite high current density in the bulk REBCO and to generate periodic magnetic field we proposed bulk superconductor staggered array undulator in 2006*. Recently we have developed the third undulaor prototype which consists of 6T solenoid and 6 period of bulk REBCO array, and successfully demonstrated periodic field amplitude of 2.22 T for period length of 10 mm and undulator gap of 4.0 mm at 7 K. In the presentation, we will summarize properties and performances of bulk REBCO superconductors and discuss on the performance of bulk superconductor staggered array undulator and potential as an insertion device for the future light sources.
* T. Kii et al.: Proc. FEL2006 (2006) p. 653.
