Home-built 95 GHz pulse EPR spectrometer
The spectrometer features electron – electron and electron nuclear double resonance capabilities (ELDOR and ENDOR). It employs a superconducting magnet with a solenoid-coil configuration that can reach a maximum field of 6T and 0.4 T sweep coils. Sample cooling is accomplished using a cryo-free system by ColdEdge. The microwave bridge of the spectrometer combines waveguide and quasi-optics technologies and is capable of generating arbitrary waveform pulses. The spectrometer is controlled by the software SpecMan (https://specman4epr.com/).
References
- HYSCORE and DEER with an upgraded 95 GHz pulse EPR spectrometer Goldfarb D., Lipkin Y., Potapov A., Gorodetsky Y., Epel B., Raitsimring A. M., Radoul M. & Kaminker I. (2008) Journal of Magnetic Resonance. 194, 1, p. 8-15
- Increasing sensitivity of pulse EPR experiments using echo train detection schemes Mentink-Vigier F., Collauto A., Feintuch A., Kaminker I., Le V. T. & Goldfarb D. (2013) Journal of Magnetic Resonance. 236, p. 117-125 Abstract
- Improved sensitivity for W-band Gd(III)-Gd(III) and nitroxide-nitroxide DEER measurements with shaped pulses Bahrenberg T., Rosenski Y., Carmieli R., Zibzener K., Qi M., Frydrnan V., Godt A., Goldfarb D. & Feintuch A. (2017) Journal of Magnetic Resonance. 283, p. 1-13
Home-built W-band (95 GHz) EPR/DNP spectrometer
This spectrometer, also operating at 95 GHz, is based on a cryofree magnet with a field that can be routinely swept from 0 to 5T. The sample cryostat is using the magnet cryostat as a first stage; in this manner, EPR spectracan be recorded as low as at 3 K. The system is by Cryogenic Ltd. In terms of EPR performance spectrometer is very similar to the pulse W-band EPR spectrometer, can carry out both ELDOR and ENDOR types of measurements. In addition, it can perform DNP (dynamic nuclear polarization) measurements (144 MHz for protons), where NMR signals are enhanced by polarization transfer from electron spins in the sample. Experiments are carried out under static conditions (no MAS).
References
- Feintuch, A.; Shimon, D.; Hovav, Y.; Banerjee, D.; Kaminker, I.; Lipkin, Y.; Zibzener, K.; Epel, B.; Vega, S.; Goldfarb, D. A Dynamic Nuclear Polarization spectrometer at 95 GHz/144 MHz with EPR and NMR excitation and detection capabilities. Journal of Magnetic Resonance 2011, 209, 136-141.
EPR core facility
In addition, we have access to the EPR core facility lab of the Chemical Research Support Unit with an X-band Elexsys E-500 CW EPR spectrometer and a Bruker Elexsys E-580 pulse/CW EPR spectrometer operating at X-band (9.5GHz) and Q-band (35 GHz) frequencies equipped with a cryo-free sample cooling system.