Nuclear spin relaxation by intermolecular magnetic dipole coupling in the gas phase. 129Xe in oxygen

The nuclear spin relaxation times (T1) of 129Xe in xenon–O2 gas mixtures have been measured as a function of temperature and density at different magnetic fields. This system is used to characterize the intermolecular dipolar relaxation of nuclear spins in the gas phase. An empirical Boltzmann-averaged collision cross section associated with the collision-induced transitions between 129Xe nuclear spin states is obtained as a function of temperature.