Spin Noise Detection of Nuclear Hyperpolarization at 1.2 K |
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Authors: | Maria Theresia Pöschko Basile Vuichoud Jonas Milani Dr. Aurélien Bornet Dr. Matthias Bechmann Prof. Geoffrey Bodenhausen Dr. Sami Jannin Prof. Norbert Müller |
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Affiliation: | 1. Institute of Organic Chemistry, Johannes Kepler University Linz, Linz, Austria;2. Institut de Sciences et Ingénerie Chimiques, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland;3. Département de Chimie, Ecole Normale Supérieure, PSL, Paris, Cedex 05, France;4. Université Pierre-et-Marie Curie, Paris (France;5. UMR 7203, CNRS/UPMC/ENS, Ecole Normale Supérieure, Paris, France;6. Bruker BioSpin AG, F?llanden, Switzerland;7. Faculty of Science, University of South Bohemia, ?eské Budějovice, Czech Republic |
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Abstract: | We report proton spin noise spectra of a hyperpolarized solid sample of commonly used “DNP (dynamic nuclear polarization) juice” containing TEMPOL (4‐hydroxy‐2,2,6,6‐tetramethylpiperidine N‐oxide) and irradiated by a microwave field at a temperature of 1.2 K in a magnetic field of 6.7 T. The line shapes of the spin noise power spectra are sensitive to the variation of the microwave irradiation frequency and change from dip to bump, when the electron Larmor frequency is crossed, which is shown to be in good accordance with theory by simulations. Small but significant deviations from these predictions are observed, which can be related to spin noise and radiation damping phenomena that have been reported in thermally polarized systems. The non‐linear dependence of the spin noise integral on nuclear polarization provides a means to monitor hyperpolarization semi‐quantitatively without any perturbation of the spin system by radio frequency irradiation. |
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Keywords: | dynamic nuclear polarization non-linear effects nuclear magnetic resonance radiation damping spin noise |
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