Bruker Elexsys E780 J-band Spectrometer

263 GHz EPR spectrometer is equipped with a quasi-optical front-end, an arbitrary waveform generator and a 9.4 T Ascend 400MHz DNP superconducting magnet system. Additional superconducting coil mounted into the magnet system allows sweeping the magnetic field in the range of +/- 80 mT around the central field. Two kinds of signal detection modes are available: induction and reflection. The probehead is equipped with an oversized corrugated waveguide with a taper and a cylindrical (TE011) cavity suited for ENDOR experiments. Oxford helium flow cryostat with a temperature control unit allows the experiments to be performed at sample temperatures varying in the range of 4 – 300 K. The spectrometer is used for cw-EPR as well as hyperfine (ENDOR and ELDOR detected NMR) and dipolar (RIDME and PELDOR/DEER with broadband excitation) spectroscopy experiments. In near future pulsed DNP experiments are planned.