Design of the Nijmegen High-Resolution FIR-FEL

In 2006, the Radboud University in Nijmegen received approval to realize a THz Free-Electron Laser (FEL) system and a 45 T hybrid magnet system. The THz-FEL system will be used in material science at high (30-45 T) magnetic fields, and applications e.g. in the field of biomolecu-lar spectroscopy. We here present the conceptual design of the Nijmegen THz-FEL. The FEL covers the 100-1500 μm spectral range and will operate in either a spectroscopic (spectral resolution better than 105) providing 100 Watt bandwidth limited pulses of several microsecond or pump-probe pulsed mode providing macropulses consisting of 3 GHz micropulses. Technical challenges are in achieving the required coherence for the narrow-band operation and in the 3 GHz operation of the source.