NMR Studies of Laser-Polarized Xenon Gas Flow in Porous and Granular Media

1. Gas Flow NMR in Porous Media • NMR studies of gas flow are a powerful probe of hydrodynamic flow and dispersion in porous media, granular flows and segregation processes – Porous media flow characterized by Peclet number: Pe = vL/D (diffusive time / coherent flow time) v = velocity, D = diffusion coefficient, L = pore size – Use of gases, with D ~ 1000 times lower than liquids, allows exploration of small Pe regime, where diffusive displacements ~ flow displacement, and where both displacements ~ pore size. – This regime is relatively unexplored due to difficulty probing such a system. – We are conducting NMR studies of laser-polarized gas flow, to characterize flow regimes and phenomena that can be observed 2. Experimental Setup • Sample held in sealed container, placed in RF coil and put in 4.7 T NMR magnet. • Sample inlet connected to polarization cell, sample outlet connected to mass flow controller and vacuum pump.