Probing the “Dead-Time” in NMR by Combining Single Pulse and Solid Echo Experiments Followed by a Global Model Fit Analysis

Abstract

The main question addressed in this work is how to probe the “effective dead-time” in an NMR instrument, i.e., the time needed to blank the receiver after an rf-pulse excitation to prevent damage to the receiver and to avoid any distortion of the NMR signal being sampled. The strategy is to design a suitable FID-model to fit the single pulse excitation (SPE) and solid echo pulse (SEPS) data (on solid Tricosane) using a Global model-fit analysis technique. The derived dead time is discussed with respect to sampling temperature (25–40 °C) and—in particular—with respect to the number of SEPS data involved in the Global fit analysis by applying the Bayesian Information Criterion (BIC) in combination with more traditional statistical analysis. It is concluded that the “effective dead time” can be determined within a standard error of less than 2.5%.