• G. Fuchert, T. Baumbach, A. Bernhard, S. Ehlers, P. Peiffer, D. Wollmann
  KIT, Karlsruhe
• R. Rossmanith
  FZK, Karlsruhe

In addition to large synchrotron radiation and FEL facilities, smaller and cheaper intense UV and X-ray facilities are needed (so-called table-top sources). The electron beam for such a table-top source could be provided by a laser wakefield accelerator. Despite dramatic improvements during the last years on stability and intensity of those devices, one disadvantage remains: the energy spread of the electron beam is in the range of several percent, leading to an energy spread of the photon beam emitted by a conventional undulator. In this paper ideas for new designs of superconductive undulators are presented, which can produce an almost monochromatic photon beam out of an electron beam with a relatively large energy spread.