Proton spin relaxation in hydrogen–nitrogen mixtures: a test of the single relaxation time approximation

Abstract

Accurate measurements of the concentration dependence of the longitudinal proton spin relaxation time in hydrogen–nitrogen mixtures at 300 K are presented. The data are taken at 39 MHz and at densities for which the short correlation time limit approximation is valid. The measurements provide definitive evidence of deviations from the single relaxation time approximation. The Bloom–Oppenheim two-level theory is used to explain the detailed concentration dependence of the data.