A sensitivity leap for X-band EPR using a probehead with a cryogenic preamplifier

Abstract 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 high microwave powers typical in pulsed EPR, and is compatible convenient resonator coupling sample access found on commercially available spectrometers. approach allows standard continuous-wave experiments to be performed at frequency significantly increased sensitivity compared unmodified setup. The probehead demonstrates voltage signal-to-noise ratio (SNR) enhancement factor close 8× temperature 6 K, remains 2× room temperature. By further suppressing room-temperature noise expense reduced power (and thus minimum ? -pulse length), SNR improvement approaches 15 corresponding impressive 200-fold reduction measurement time. We reveal full potential this demonstrating such improvements using suite hyperfine dipolar spectroscopy exemplary samples.