Nmr Probe for Dynamic-Angle Spinning

TitleNmr Probe for Dynamic-Angle Spinning
Publication TypeJournal Article
Year of Publication1991
AuthorsMueller K.T, Chingas G.C, Pines A
JournalReview of Scientific Instruments
Date PublishedJun
ISBN Number0034-6748
Accession NumberWOS:A1991FP31200011

We describe the design of a probe for dynamic-angle spinning (DAS) NMR experiments, comprised of a spinning cylindrical sample holder whose axis may be reoriented rapidly between discrete directions within the bore of a superconducting magnet. This allows the refocusing of nuclear spin magnetization that evolves under anisotropic interactions such as chemical shift anisotropy and quadrupolar coupling, providing high resolution NMR spectra for quadrupolar nuclei in solid materials. The probe includes an axial air delivery system to bearing and drive jets which support and spin a rotor containing the sample. Axis reorientation is accomplished with a pulley attached to the probehead and coupled to a stepping motor outside of the magnet. The choice of motor and gear ratio is based on an analysis of the moments of inertia of the motor and load, the desired angular resolution, and simplicity of design. Control of angular accuracy and precision are discussed, as well as the efficiency of radiofrequency irradiation and detection. High resolution DAS spectra of oxygen-17 and aluminum-27 nuclei in polycrystalline minerals illustrate the experimental capabilities.

URL<Go to ISI>://WOS:A1991FP31200011
Short TitleNmr Probe for Dynamic-Angle Spinning
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