In this paper we discuss the possibility of modifying the multiple spin echoes existing theory, developed for a homogeneous system, to describe also an inhomogeneous system such as a porous medium. We report here the first experimental application of MSE methods to materials like travertine. The ratio A2/A1 from water in travertine presents minima for characteristic values of the delay time t, like what was previously observed in the trabecular bone. By a judicious choice of the delay time t and of the G gradient strength, the MSE sequence can be made sensitive to a specific length-scale of the sample heterogeneity. Furthermore the MSE image shows a particular new contrast that makes the non linear NMR method very attractive for the assessment of variations of the porous structure in porous systems
Characterization of porous media micro- structure by non linear NMR methods
S Capuani;
2001
Abstract
In this paper we discuss the possibility of modifying the multiple spin echoes existing theory, developed for a homogeneous system, to describe also an inhomogeneous system such as a porous medium. We report here the first experimental application of MSE methods to materials like travertine. The ratio A2/A1 from water in travertine presents minima for characteristic values of the delay time t, like what was previously observed in the trabecular bone. By a judicious choice of the delay time t and of the G gradient strength, the MSE sequence can be made sensitive to a specific length-scale of the sample heterogeneity. Furthermore the MSE image shows a particular new contrast that makes the non linear NMR method very attractive for the assessment of variations of the porous structure in porous systemsI documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
