Optical pumping has been used to enhance the pulsed NMR signal of ${}_{}{}^{129}{}_{}{}^{}\mathrm{Xe}$, allowing the detecting of low-pressure xenon gas and of xenon adsorbed on powdered solids. We observe an increase in sensitivity of more than 2 orders of magnitude over conventional NMR, the current limitation being the laser power. Adsorbed xenon is observed at 298 K on graphitized carbon (about 10 ${\mathrm{m}}^2$g and on powdered benzanthracene (∼0.5 ${\mathrm{m}}^2$g) below 170 K. The increased sensitivity of this technique allows the study of a large class of amorphous materials with surface areas below 10 ${\mathrm{m}}^2$/g including semiconductors, polymers, metal oxides, and catalysts.

• Received 27 November 1990

DOI:https://doi.org/10.1103/PhysRevLett.66.584