Evidence for relaxation of xenon-129 by paramagnetic impurities on rubidium hydride surfaces

Data are presented on the wall-induced spin-relaxaton rates of 129Xe in glass cells in winch the interior walls are coated with rubidium hydride (RbH). The relaxation rates have been measured as a function of both magnetic field and temperature. The relaxation rates have been measured at fields ranging from 0.01--1.00 Tesla, and are found to decrease significantly with increasing magnetic field These magnetic decoupling curves are qualitatively similar for cells coated with both rubidium hydride as well as rubidium deuteride. The characteristic widths of the decoupling curves show only mild variation with temperature over the range of 223 K--323 K. The observed behavior of the relaxation is consistent with that expected due to paramagnetic sites, although the correlation times of the interactions are surprisingly long, on the order of 10--30 picoseconds.