Unilateral NMR with a barrel magnet

Unilateral NMR can examine samples without regard to sample size. It is also an easy path to mobile or portable NMR as well as inexpensive NMR. The objective of this work was to develop unilateral NMR with an improved performance in a sample region that was remote from the apparatus. This was accomplished with the creation of a saddle point where all second derivatives of the main component of the field were nulled. A similar to 10 cm diameter similar to 5 cm thick magnet combined with a gradiometer coil on the surface detected signals from a sensitive region that extended similar to 2 cm from the magnet. The relatively homogeneous field of these unilateral NMR devices allows the measurement of rapidly diffusing spins as well as the use of smaller RF amplifiers, which enhances system mobility. (C) 2017 Elsevier Inc. All rights reserved.