title: Low-cost, pseudo-Halbach dipole magnets for NMR.
abstract: We present designs for compact, inexpensive and strong dipole permanent magnets aimed primarily at magnetic resonance applications where prepolarization and detection occur at different locations. Low-homogeneity magnets with a 7.5mm bore size and field up to nearly 2T are constructed using low-cost starting materials, standard workshop tools and only few hours of labor - an achievable project for a student or postdoc with spare time. As an application example we show how our magnet was used to polarize the nuclear spins in approximately 1mL of pure [13C]-methanol prior to detection of its high-resolution NMR spectrum at zero field (measurement field below 10-10T), where signals appear at multiples of the carbon-hydrogen spin-spin coupling frequency1JCH=140.7(1)Hz.
authors.affiliation: Magnetic Resonance Research Center, Department of Chemical Engineering and Biotechnology, University of Cambridge, Cambridge, UK; Department of Physics, University of California, Berkeley, CA 94720, USA. Electronic address: mcdt2@cam.ac.uk.
authors.forename: Michael C D
authors.initials: MCD
authors.lastname: Tayler
authors.affiliation: NIMBE, CEA-CNRS, Université Paris-Saclay, CEA Saclay, 91191 Gif-sur-Yvette Cedex, France.
authors.forename: Dimitrios
authors.initials: D
authors.lastname: Sakellariou
keywords: Low-field NMR; Nuclear magnetic resonance (NMR); Permanent magnets; Zero-field NMR