Kalendra, Vidmantas, Justinas Turčak, Gediminas Usevičius, Hugo Karas, Miriam Hülsmann, Adelheid Godt, Gunnar Jeschke, Jūras Banys, John J.L. Morton, and Mantas Šimėnas. “Q-Band EPR Cryoprobe.” Journal of Magnetic Resonance 356 (November 2023): 107573.
https://doi.org/10.1016/j.jmr.2023.107573.
Following the success of cryogenic EPR signal preamplification at X-band, we present a Q-band EPR cryoprobe compatible with a standard EPR resonator. The probehead is equipped with a cryogenic ultra low-noise microwave amplifier and its protection circuit that are placed close to the sample in the same cryostat. Our cryoprobe maintains the same sample access and tuning which is typical in Q-band EPR, as well as supports high-power pulsed experiments on typical samples. The performance of our setup is benchmarked against that of existing commercial and home-built Q-band spectrometers, using CW EPR and pulsed EPR/ENDOR experiments to reveal a significant sensitivity improvement which reduces the measurement time by a factor of about 40× at 6 K temperature at reduced power levels.