A sensitivity leap for X-band EPR using a probehead with a cryogenic preamplifier
File(s)cas-dc-template.pdf (1.25 MB) aipsamp.pdf (483.32 KB)
Accepted version
Supporting information
Author(s)
Type
Journal Article
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 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.
Date Issued
2021-01
Date Acceptance
2020-11-12
Citation
Journal of Magnetic Resonance, 2021, 322, pp.1-7
ISSN
1090-7807
Publisher
Elsevier BV
Start Page
1
End Page
7
Journal / Book Title
Journal of Magnetic Resonance
Volume
322
Copyright Statement
© 2020 Elsevier Ltd. All rights reserved. This manuscript is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International Licence http://creativecommons.org/licenses/by-nc-nd/4.0/
Sponsor
The Leverhulme Trust
Identifier
https://www.sciencedirect.com/science/article/pii/S1090780720301944?via%3Dihub
Grant Number
RPG-2018-183
Subjects
Biophysics
02 Physical Sciences
09 Engineering
Publication Status
Published online
Article Number
106876
Date Publish Online
2020-11-17