Speaker
Description
Aiming at the very small-scale NMR magnets, the authors have studied to detect NMR signals for NMR relaxometry using the single-sided magnetic pole which contained the high temperature superconducting (HTS) bulk magnet. The NMR signal relaxation rate depends on the mobility of molecules, including fluctuations and diffusion, in the microscopic environment. This measurement method can acquire less information compared to ordinary NMR spectroscopy, but instead less magnetic field homogeneity is needed. The higher magnetic field strength achieved by HTS bulk magnet can give us a benefit of higher sensitivity for shorter measurement time and stronger magnetic field gradient for higher spatial resolution, compared to commonly used permanent magnet. Pulsed field magnetizing method was employed to activate the bulk magnet as the most compact and the easiest way to handle, which gave us the magnetic pole emitting intense field of 1.32 T at the surface. We measured the spin-echo signals of hydrogen emitted from a silicon rubber sample with a diameter of 4 mm and a length of 9.5 mm in the probe which was placed on the surface centre of the magnetic pole, and have succeeded in detecting the NMR signals at 47.8 MHz, installing the sample 3.7 mm away from the surface. This is the first single-sided NMR signal detection with use of the single-sided magnetic pole containing bulk magnet in the world.
