A short period cryogenic undulator for future compact X-ray FEL

Short period, high field undulators can enable short wavelength free electron lasers (FELs) at low beam energy. A research group led by Professor J. Rosenzweig (University of California, Los Angeles, USA) has recently unveiled a new design based on an approach that utilizes cryogenic materials. For more information, see the paper, "Short period, high field cryogenic undulator for extreme performance x-ray free electron lasers", F. H. O'Shea et al., Phys. Rev. ST Accel. Beams 13, 070702 (2010).