Artículo
Longitudinal gradient coils with enhanced radial uniformity in restricted diameter: Single-current and multiple-current approaches
Fecha de publicación:
03/2017
Editorial:
Academic Press Inc Elsevier Science
Revista:
Journal Of Magnetic Resonance
ISSN:
1090-7807
Idioma:
Inglés
Tipo de recurso:
Artículo publicado
Clasificación temática:
Resumen
An important requirement for a gradient coil is that the uniformity of the generated magnetic field gradient should be maximal within the active volume of the coil. For a cylindrical geometry, the radial uniformity of the gradient turns critic, particularly in cases where the gradient-unit has to be designed to fit into the inner bore of a compact magnet of reduced dimensions, like those typically used in fast-field-cycling NMR. In this paper we present two practical solutions aimed to fulfill this requirement. We propose a matrix-inversion optimization algorithm based on the Biot-Savart law, that using a proper cost function, allows maximizing the uniformity of the gradient and power efficiency. The used methodology and the simulation code were validated in a single-current design, by comparing the computer simulated field map with the experimental data measured in a real prototype. After comparing the obtained results with the target field approach, a multiple-element coil driven by independent current sources is discussed, and a real prototype evaluated. Opposed equispaced independent windings are connected in pairs conforming an arrangement of independent anti-Helmholtz units. This last coil seizes 80% of its radial dimension with a gradient uniformity better than 5%. The design also provides an adaptable region of uniformity along with adjustable coil efficiency.
Palabras clave:
Field-Cycling
,
Gradient Coils
,
Multiple-Current
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Articulos(IFEG)
Articulos de INST.DE FISICA ENRIQUE GAVIOLA
Articulos de INST.DE FISICA ENRIQUE GAVIOLA
Citación
Romero, Javier Agustin; Dominguez, Gabriela Alejandra; Anoardo, Esteban; Longitudinal gradient coils with enhanced radial uniformity in restricted diameter: Single-current and multiple-current approaches; Academic Press Inc Elsevier Science; Journal Of Magnetic Resonance; 276; 3-2017; 69-77
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