129Xe NMR spectroscopy is a powerful tool to probe porous solids, but
suffers sometimes from limitations
in signal-to-noise ratio due to the low spin density of a gas. This problem
can be overcome by optically spin-polarizing xenon gas,
instead of relying
on its small thermal equilibrium polarization as obtained in a typical NMR
magnet. This technique has been carried out initially by polarizing
single batches of xenon. A more flexible technique, which opens the way to
signal averaging and multiple pulse experiments, is to continuously
polarize the xenon and let it circulate over the sample surface. A
schematic of our experimental setup is shown on the left.
The design has been
adapted from: R. Seydoux, A. Pines, M. Haake and J. A. Reimer, J. Phys. Chem.
B 103, 4629-4637 (1999).
