OPTIMIZATION OF 2-STAGE MEASUREMENTS OF T-1

A recent analysis of the optimization of adaptive T-1 measurements bas ed on inversion-recovery (IR) experiments is extended to allow for the use of fast-inversion-recovery (FIR) experiments in either of the two stages of the experiment. FIR experiments can be carried out more qui ckly than IR experiments but individual measurements are inherently le ss precise. Both types of experiments are considered, with a fixed num ber of times at which measurements are made and with a fixed total run ning time. The results of the investigation suggest that an optimal tw o-stage experiment with a fixed number of measurements makes use of th e FIR technique in the first stage and IR in the second. When the tota l running time is fixed, it is generally better to use FIR in both sta ges. (C) 1994 Academic Press, Inc.