NMR measurements of grain and gas motion in a gas-fluidized granular bed.

Nuclear magnetic resonance (NMR) experiments are described for gas-fluidized granular beds, which are important systems for many materials-processing operations. Using pulsed field gradient, magnetic resonance imaging, and hyperpolarized gas NMR, detailed information is obtained for the density and motions of both grains and interstitial gas. In particular, dynamic correlations in the grain density are used to measure the bubble velocity and hyperpolarized xenon gas NMR is used to measure the bubble-emulsion exchange rate. A goal of these measurements is to verify in earth gravity first-principles theories of granular flows. [ABSTRACT FROM AUTHOR]