Praseodymium iron-boron undulator with textured dysprosium poles for compact x-ray fel applications

The next generation light sources require development of the insertion devices with shorter periods and higher peak field values, well beyond the presently available designs limited by magnetic properties of conventional materials. Radiabeam Technologies is developing a novel ultra-high field short period undulator using two unconventional materials: praseodymium permanent magnets (PrFeB) and textured dysprosium (Tx Dy) ferromagnetic field concentrators. Both materials exhibit extraordinary magnetic properties at cryogenic temperatures, such as very large energy product and record high induction saturation, respectively. The proposed device combines PrFeB and Tx Dy in 3-D hybrid undulator geometry with sub-cm period and up to 3 Tesla pole tip field. Practical realization of these features will significantly surpass state-of-the-art and offer an ideal solution for the next generation of compact X-ray light sources. Textured Dy development status, along with initial simulations, and proof of concept prototype cryogenic measurements will be presented.