A versatile custom cryostat for dynamic nuclear polarization supports multiple cryogenic magic angle spinning transmission line probes.

Autor: Scott FJ; Department of Chemistry, Washington University in St. Louis, St. Louis, MO 63130, USA., Alaniva N; Department of Chemistry, Washington University in St. Louis, St. Louis, MO 63130, USA., Golota NC; Department of Chemistry, Washington University in St. Louis, St. Louis, MO 63130, USA., Sesti EL; Department of Chemistry, Washington University in St. Louis, St. Louis, MO 63130, USA., Saliba EP; Department of Chemistry, Washington University in St. Louis, St. Louis, MO 63130, USA., Price LE; Department of Chemistry, Washington University in St. Louis, St. Louis, MO 63130, USA., Albert BJ; Department of Chemistry, Washington University in St. Louis, St. Louis, MO 63130, USA., Chen P; Department of Chemistry, Washington University in St. Louis, St. Louis, MO 63130, USA; Department of Physics, Washington University in St. Louis, St. Louis, MO 63130, USA., O'Connor RD; Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, MD 20892, USA., Barnes AB; Department of Chemistry, Washington University in St. Louis, St. Louis, MO 63130, USA. Electronic address: barnesab@wustl.edu.
Jazyk: angličtina
Zdroj: Journal of magnetic resonance (San Diego, Calif. : 1997) [J Magn Reson] 2018 Dec; Vol. 297, pp. 23-32. Date of Electronic Publication: 2018 Oct 03.
DOI: 10.1016/j.jmr.2018.10.002
Abstrakt: Dynamic nuclear polarization (DNP) with cryogenic magic angle spinning (MAS) provides significant improvements in NMR sensitivity, yet presents unique technical challenges. Here we describe a custom cryostat and suite of NMR probes capable of manipulating nuclear spins with multi-resonant radiofrequency circuits, cryogenic spinning below 6 K, sample exchange, and microwave coupling for DNP. The corrugated waveguide and six transfer lines needed for DNP and cryogenic spinning functionality are coupled to the probe from the top of the magnet. Transfer lines are vacuum-jacketed and provide bearing and drive gas, variable temperature fluid, two exhaust pathways, and a sample ejection port. The cryostat thermally isolates the magnet bore, thereby protecting the magnet and increasing cryogen efficiency. This novel design supports cryogenic MAS-DNP performance over an array of probes without altering DNP functionality. We present three MAS probes (two supporting 3.2 mm rotors and one supporting 9.5 mm rotors) interfacing with the single cryostat. Mechanical details, transmission line radio frequency design, and performance of the cryostat and three probes are described.
(Copyright © 2018. Published by Elsevier Inc.)
Databáze: MEDLINE
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