Zur kernmagnetischen Relaxation in Mehrbereichsystemen mit endlicher räumlicher Ausdehnung



General equations, describing the nuclear spin relaxation behaviour in heterogeneous systems, consisting of regions with different relaxation times and diffusion coefficients, are presented. For a special two region system, by means of analogue computing technique the influence of both diffusivity and height of the barriers between the regions on total relaxation is studied. It is shown, that using appropriate expressions for the mean lifetimes of the nuclei in the regions, the relaxation function of total magnetisation may be approximated by the formulae of ZIMMERMAN and BRITTIN. These relations may be used for a rough estimation of diffusivity in the systems under consideration.