PSI, Villigen
The proposed SwissFEL will provide both hard x-rays down to 1Å and soft x-rays with full polarization control with a rather small electron energy of 5.8GeV. This continues the strategy of the medium energy synchrotron facilities, namely the SLS. The U15 and UE40 undulators are based on the experience with small period, small gap in-vacuum undulators and of APPLE II type respectively but are optimized for FEL operation. The undulator design including room temperature versus cryogenic principle, field optimization, materials and the demands for a series production will be discussed.
