Air core notch-coil magnet with variable geometry for fast-field-cycling NMR

STEPHAN KRUBER; GERMÁN D. FARRHER; ESTEBAN ANOARDO

JOURNAL OF MAGNETIC RESONANCE

ACADEMIC PRESS INC ELSEVIER SCIENCE

Lugar: Amsterdam; Año: 2015 vol. 259 p. 216 - 224

1090-7807

In this manuscript we present details on the optimization, construction and performance of a wide-bore(71 mm) a-helical-cut notch-coil magnet with variable geometry for fast-field-cycling NMR. In additionto the usual requirements for this kind of magnets (high field-to-power ratio, good magnetic fieldhomogeneity, low inductance and resistance values) a tunable homogeneity and a more uniform heatdissipation along the magnet body are considered. The presented magnet consists of only one machinedmetallic cylinder combined with two external movable pieces. The optimal configuration is calculatedthrough an evaluation of the magnetic flux density within the entire volume of interest. The magnethas a field-to-current constant of 0:728 mT/A, allowing to switch from zero to 0:125 T in less than3 ms without energy storage assistance. For a cylindrical sample volume of 35 cm3 the effective magnethomogeneity is lower than 130 ppm.