Field-cycling NMR experiments in an ultra-wide magnetic field range: relaxation and coherent polarization transfer

2018 ◽  
Vol 20 (18) ◽  
pp. 12396-12405 ◽  
Author(s):  
Ivan V. Zhukov ◽  
Alexey S. Kiryutin ◽  
Alexandra V. Yurkovskaya ◽  
Yuri A. Grishin ◽  
Hans-Martin Vieth ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Magnetic Fields ◽  
Experimental Method ◽  
Field Range ◽  
Magnetic Field Range ◽  
Wide Range ◽  
Field Cycling ◽  
Fast Field

An experimental method is described allowing fast field-cycling Nuclear Magnetic Resonance (NMR) experiments over a wide range of magnetic fields from 5 nT to 10 T.

Comparative study of helical-cut notch–coil magnets for fast-field-cycling nuclear magnetic resonance

2014 ◽  
Vol 92 (11) ◽  
pp. 1430-1440 ◽  
Author(s):  
S. Kruber ◽  
G.D. Farrher ◽  
E. Anoardo
Keyword(s):  
Magnetic Field ◽  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Magnet System ◽  
Fast Switching ◽  
Magnetic Field Homogeneity ◽  
Field Cycling ◽  
Fast Field ◽  
The Magnetic Field ◽  
Nuclear Magnetic

In this manuscript we describe an α-helical-cut notch–coil magnet system designed for fast switching of the magnetic field. An attempt was made to determine the extent to which such a magnet configuration can be efficiently used for fast-field-cycling (FFC) nuclear magnetic resonance (NMR) instruments. In addition to the typical technical requirements (high field-to-power ratio, adequate electric performance for fast-switching of the magnetic field and NMR-compatible magnetic field homogeneity), a tunable homogeneity within the sample volume and more uniform heat dissipation along the magnet body are included. A helical-cut notch–coil machined in metallic cylinders with external movable pieces was found to fit these requirements very well. A key factor for the optimization of the magnet parameters is the use of a novel calculation procedure based on a more realistic model that consider a magnet geometry with broken azimuthal symmetry. The aim of this paper is to theoretically compare the proposed geometry with other existing designs. No particular prototype is presented here. A clear understanding of the notch–coil performance was found to be an essential step for its further consideration as a potential autoadaptive (electronically controlled) magnet system for FFC applications.

Nuclear magnetic resonance microscopy

1989 ◽  
Vol 47 ◽  
pp. 828-829
Author(s):  
Paul C. Lauterbur
Keyword(s):  
Magnetic Field ◽  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Magnetic Fields ◽  
Signal To Noise ◽  
Field Gradients ◽  
Useful Signal ◽  
Magnetic Field Gradients ◽  
Observation Times ◽  
Nuclear Magnetic

Nuclear magnetic resonance imaging can reach microscopic resolution, as was noted many years ago, but the first serious attempt to explore the limits of the possibilities was made by Hedges. Resolution is ultimately limited under most circumstances by the signal-to-noise ratio, which is greater for small radio receiver coils, high magnetic fields and long observation times. The strongest signals in biological applications are obtained from water protons; for the usual magnetic fields used in NMR experiments (2-14 tesla), receiver coils of one to several millimeters in diameter, and observation times of a number of minutes, the volume resolution will be limited to a few hundred or thousand cubic micrometers. The proportions of voxels may be freely chosen within wide limits by varying the details of the imaging procedure. For isotropic resolution, therefore, objects of the order of (10μm) may be distinguished.Because the spatial coordinates are encoded by magnetic field gradients, the NMR resonance frequency differences, which determine the potential spatial resolution, may be made very large. As noted above, however, the corresponding volumes may become too small to give useful signal-to-noise ratios. In the presence of magnetic field gradients there will also be a loss of signal strength and resolution because molecular diffusion causes the coherence of the NMR signal to decay more rapidly than it otherwise would. This phenomenon is especially important in microscopic imaging.

Large volume liquid state scalar Overhauser dynamic nuclear polarization at high magnetic field

2019 ◽  
Vol 21 (38) ◽  
pp. 21200-21204 ◽  
Author(s):  
Thierry Dubroca ◽  
Sungsool Wi ◽  
Johan van Tol ◽  
Lucio Frydman ◽  
Stephen Hill
Keyword(s):  
Magnetic Field ◽  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Magnetic Fields ◽  
High Magnetic Field ◽  
Dynamic Nuclear Polarization ◽  
Large Volume ◽  
Liquid State ◽  
Nuclear Polarization ◽  
High Magnetic Fields

Dynamic Nuclear Polarization (DNP) can increase the sensitivity of Nuclear Magnetic Resonance (NMR), but it is challenging in the liquid state at high magnetic fields.

SABRE Hyperpolarization of Bipyridine Stabilized Ir-Complex at High, Low and Ultralow Magnetic Fields

2017 ◽  
Vol 231 (3) ◽  
Author(s):  
Andrey N. Pravdivtsev
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Magnetic Fields ◽  
Dynamic Nuclear Polarization ◽  
Signal Amplification ◽  
Nuclear Polarization ◽  
Optical Pumping ◽  
Spin Exchange ◽  
Spin Exchange Optical Pumping ◽  
Wide Range

AbstractA strong limitation of nuclear magnetic resonance is its low inherent sensitivity that can be overcome by using an appropriate hyperpolarization technique. Presently, dynamic nuclear polarization and spin-exchange optical pumping are the only hyperpolarization techniques that are used in applied medicine. However, both are relatively complex in use and expensive. Here we present a modification of the signal amplification by reversible exchange (SABRE) hyperpolarization method – SABRE on stabilized Ir-complexes. A stabilized Ir-complex (here we used bipyridine for stabilization) can be hyperpolarized in a wide range of magnetic fields from a few μT upto 10 T with

scholarly journals Nuclear Magnetic Resonance with Fast Field-Cycling Setup: A Valid Tool for Soil Quality Investigation

Agronomy ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 1040 ◽  
Author(s):  
Pellegrino Conte ◽  
Paolo Lo Meo
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Nutrient Dynamics ◽  
Relaxation Times ◽  
Liquid Mixtures ◽  
Soil Science ◽  
Nmr Relaxometry ◽  
Field Cycling ◽  
Fast Field ◽  
Nuclear Magnetic

Nuclear magnetic resonance (NMR) techniques are largely employed in several fields. As an example, NMR spectroscopy is used to provide structural and conformational information on pure systems, while affording quantitative evaluation on the number of nuclei in a given chemical environment. When dealing with relaxation, NMR allows understanding of molecular dynamics, i.e., the time evolution of molecular motions. The analysis of relaxation times conducted on complex liquid–liquid and solid–liquid mixtures is directly related to the nature of the interactions among the components of the mixture. In the present review paper, the peculiarities of low resolution fast field-cycling (FFC) NMR relaxometry in soil science are reported. In particular, the general aspects of the typical FFC NMR relaxometry experiment are firstly provided. Afterwards, a discussion on the main mathematical models to be used to “read” and interpret experimental data on soils is given. Following this, an overview on the main results in soil science is supplied. Finally, new FFC NMR-based hypotheses on nutrient dynamics in soils are described

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