%V 322
%K DEER, EPR, HYSCORE, Preamplifier, Probehead, SNR enhancement
%T A sensitivity leap for X-band EPR using a probehead with a cryogenic preamplifier
%C United States
%D 2021
%X Inspired by the considerable success of cryogenically cooled NMR cryoprobes, we present an upgraded X-band EPR probehead, equipped with a cryogenic low-noise preamplifier. Our setup suppresses source noise, can handle the high microwave powers typical in X-band pulsed EPR, and is compatible with the convenient resonator coupling and sample access found on commercially available spectrometers. Our approach allows standard pulsed and continuous-wave EPR experiments to be performed at X-band frequency with significantly increased sensitivity compared to the unmodified setup. The probehead demonstrates a voltage signal-to-noise ratio (SNR) enhancement by a factor close to 8× at a temperature of 6 K, and remains close to 2× at room temperature. By further suppressing room-temperature noise at the expense of reduced microwave power (and thus minimum -pulse length), the factor of SNR improvement approaches 15 at 6 K, corresponding to an impressive 200-fold reduction in EPR measurement time. We reveal the full potential of this probehead by demonstrating such SNR improvements using a suite of typical hyperfine and dipolar spectroscopy experiments on exemplary samples.
%L discovery10117477
%O This version is the author accepted manuscript. For information on re-use, please refer to the publisher’s terms and conditions.
%A M Å imÄ—nas
%A J O'Sullivan
%A CW Zollitsch
%A O Kennedy
%A M Seif-Eddine
%A I Ritsch
%A M Hülsmann
%A M Qi
%A A Godt
%A MM Roessler
%A G Jeschke
%A JJL Morton
%J Journal of Magnetic Resonance