NMR Relaxometry Using Outer Field of Single-Sided HTS Bulk Magnet Activated by Pulsed Field

Abstract

We have succeeded in getting <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">1</sup> H NMR signals at 47.8 MHz (1.12 T) from a single-sided HTS bulk magnet activated by pulse-field magnetization. Diffusion NMR using an inhomogeneous outer field was also demonstrated on the surface. This kind of NMR relaxometry can not get the information of molecular structures, which conventional NMR using a homogeneous magnetic field can acquire. However, the relaxation of nuclear spin magnetization is still observable. A higher magnetic field gradient generated by the small HTS bulk magnet, 67 T/m at a 5 mm distance from the surface, can be effectively used to observe the self-diffusion coefficient of liquids in higher spatial resolution, 44 μm. The easy accessibility to the strong field gradient is one of the unique properties ofcompact HTS bulk magnets. We believe that single-sided (unilateral) diffusion NMR will become the new application of HTS bulk magnets.