Cross-relaxation dynamics between laser-polarized xenon and a surface species using a simple three-spin model

We present an analysis of the cross-relaxation dynamics between optically polarized 129Xe and surface 13C and 1H spins in methanol adsorbed on a SiO2 surface. Analytical expressions for the 13C polarization are derived, which show that the 13C polarization is determined by cross-relaxation with both 129Xe and 1H spins. The 1H spins act as a polarization sink; however, saturation of the protons results in a further increase in signal intensity. Replacing the 1H spin reservoir with 2H increases the 13C signal by a factor of 12 (25 as compared to room-temperature data). Further improvements are anticipated using higher-powered lasers.