An alternative to the inversion-recovery method for estimating Rz is the saturation-recovery experiment. This starts with the spin being irradiated for a long time so that it becomes saturated, i.e. MZ = 0. There then follows a delay Ï„, followed by a 90° pulse and then observation of the FID.
Show that the z-magnetization at the end of Ï„ is given by

make a sketch of Mz(Ï„) as a function of Ï„.
Explain how the data from a series of experiments recorded with increasing values of Ï„ can be used, in conjunction with a graphical method, to estimate Rz.

M.(r) = M [1 - exp(-RT)]: