SQUID DETECTED NMR OF LASER-POLARIZED XENON AT 4.2 K AND AT FREQUENCIES DOWN TO 200 HZ

A spectrometer based on a dc SQUID (superconducting quantum interferen ce device) was used to record nuclear magnetic resonance signals from laser-polarized Xe-129 at 4.2 K and at frequencies ranging from about 200 Hz to 110 kHz in magnetic fields varying from about 0.02 to 9 mT. The Xe-129 resonance linewidths were found to increase with increasing magnetic field, and, at a given field, to increase with higher Xe-129 concentration. The spin-lattice relaxation times were observed to dec rease from similar to 8000 s at 5 mT to similar to 2000 s at fields be low 0.05 mT. Such long relaxation times make possible a variety of spi n polarization transfer experiments. (C) 1997 Published by Elsevier Sc ience B.V.