New Approach to Analyze 2D Map T <inf>1</inf>–T <inf>2</inf>

Abstract

© 2020, Springer-Verlag GmbH Austria, part of Springer Nature. Based on the method of two-dimensional (2D) nuclear magnetic resonance (NMR) relaxometry, a technique was developed for determining the joint distribution of the correlation time τc and the Van Vleck second moments Δ ω2. The field of application is the study of slow molecular motions corresponding to the condition of the ratio of nuclear magnetic relaxation times T1/T2 > 1.05 (the relation of spin–lattice relaxation time T1 to spin–spin relaxation time T2). The technique is based on the use of a priori information about the mechanism of nuclear magnetic relaxation in a system. The technique has used this information in the regularization solution of an inverse problem. In contrast to the known method for calculating 2D maps of the joint distribution P2 (T1, T2), the proposed method for constructing a 2D map of the joint distribution Q2(τc, Δ ω2) does not depend on the main characteristic of the NMR relaxometer—the resonance frequency ω. The technique was used to analyze the characteristics of sorbed water in clay rocks–argillite.