Magnetic Flux Density Distribution in the Air Gap of a Ferromagnetic Core With Superconducting Blocks: Three-Dimensional Analysis and Experimental NMR Results
Roque, A. Roque
; Sousa, D. M. Sousa
; Margato, E. M.
; Marques, G. D.
IEEE Transactions on Applied Superconductivity Vol. 25, Nº 6, pp. Art. ID 4301609 - Art. ID 4301609, December, 2015.
ISSN (print): 1051-8223
Journal Impact Factor: 1,235 (in )
Digital Object Identifier: 10.1109/TASC.2015.2483599
The design of magnetic cores can be carried out by
taking into account the optimization of different parameters in
accordance with the application requirements. Considering the
specifications of the fast field cycling nuclear magnetic resonance
(FFC-NMR) technique, the magnetic flux density distribution,
at the sample insertion volume, is one of the core parameters
that needs to be evaluated. Recently, it has been shown that the
FFC-NMR magnets can be built on the basis of solenoid coils
with ferromagnetic cores. Since this type of apparatus requires
magnets with high magnetic flux density uniformity, a new type
of magnet using a ferromagnetic core, copper coils, and superconducting
blocks was designed with improved magnetic flux density
distribution. In this paper, the designing aspects of the magnet
are described and discussed with emphasis on the improvement of
the magnetic flux density homogeneity (ΔB/B0) in the air gap.
The magnetic flux density distribution is analyzed based on 3-D
simulations and NMR experimental results.