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NMR spectroscopy in inhomogeneous B-0 and B-1 fields with non-linear correlation

Topgaard, Daniel LU ; Sakellariou, D. and Pines, A. (2005) In Journal of Magnetic Resonance 175(1). p.1-10
Abstract
Resolved NMR spectra from samples in inhomogeneous B-0 and B-1 fields can be obtained with the so-called "ex situ" methodology, employing a train of composite or adiabatic z-rotation RF pulses to periodically refocus the inhomogeneous broadening during the detection of the time-domain signal. Earlier schemes relied on a linear correlation between the inhomogeneous B0 and B, fields. Here the pulse length, bandwidth, and amplitude of the adiabatic pulses of the hyperbolic secant type are adjusted to improve the refocusing for a setup with non-linear correlation. The field correlation is measured using a two-dimensional nutation experiment augmented with a third dimension with varying RF carrier frequency accounting for off-resonance effects.... (More)
Resolved NMR spectra from samples in inhomogeneous B-0 and B-1 fields can be obtained with the so-called "ex situ" methodology, employing a train of composite or adiabatic z-rotation RF pulses to periodically refocus the inhomogeneous broadening during the detection of the time-domain signal. Earlier schemes relied on a linear correlation between the inhomogeneous B0 and B, fields. Here the pulse length, bandwidth, and amplitude of the adiabatic pulses of the hyperbolic secant type are adjusted to improve the refocusing for a setup with non-linear correlation. The field correlation is measured using a two-dimensional nutation experiment augmented with a third dimension with varying RF carrier frequency accounting for off-resonance effects. The pulse optimization is performed with a computer algorithm using the experimentally determined field correlation and a standard adiabatic z-rotation pulse as a starting point for the iterative optimization procedure. The shape of the z-rotation RF pulse is manipulated to provide refocusing for the conditions given by the sample-, magnet-, and RF-coil geometry. (c) 2005 Elsevier Inc. All rights reserved. (Less)
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author
organization
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type
Contribution to journal
publication status
published
subject
in
Journal of Magnetic Resonance
volume
175
issue
1
pages
1 - 10
publisher
Elsevier
external identifiers
  • wos:000230050200001
  • pmid:15949743
  • scopus:19944378854
ISSN
1096-0856
DOI
10.1016/j.jmr.2005.03.006
language
English
LU publication?
yes
id
7af77ec0-cd4b-4ef7-881d-d835c174f9f1 (old id 157637)
date added to LUP
2007-07-12 13:27:08
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2017-01-01 06:56:36
@article{7af77ec0-cd4b-4ef7-881d-d835c174f9f1,
  abstract     = {Resolved NMR spectra from samples in inhomogeneous B-0 and B-1 fields can be obtained with the so-called "ex situ" methodology, employing a train of composite or adiabatic z-rotation RF pulses to periodically refocus the inhomogeneous broadening during the detection of the time-domain signal. Earlier schemes relied on a linear correlation between the inhomogeneous B0 and B, fields. Here the pulse length, bandwidth, and amplitude of the adiabatic pulses of the hyperbolic secant type are adjusted to improve the refocusing for a setup with non-linear correlation. The field correlation is measured using a two-dimensional nutation experiment augmented with a third dimension with varying RF carrier frequency accounting for off-resonance effects. The pulse optimization is performed with a computer algorithm using the experimentally determined field correlation and a standard adiabatic z-rotation pulse as a starting point for the iterative optimization procedure. The shape of the z-rotation RF pulse is manipulated to provide refocusing for the conditions given by the sample-, magnet-, and RF-coil geometry. (c) 2005 Elsevier Inc. All rights reserved.},
  author       = {Topgaard, Daniel and Sakellariou, D. and Pines, A.},
  issn         = {1096-0856},
  language     = {eng},
  number       = {1},
  pages        = {1--10},
  publisher    = {Elsevier},
  series       = {Journal of Magnetic Resonance},
  title        = {NMR spectroscopy in inhomogeneous B-0 and B-1 fields with non-linear correlation},
  url          = {http://dx.doi.org/10.1016/j.jmr.2005.03.006},
  volume       = {175},
  year         = {2005},
}