Chapter 12, Problem 12C.3BE

Interpretation Introduction

Interpretation:

The time after which the envelope of free induction decay decreases to half of its initial amplitude when the transverse relaxation time, $T_2$ is $\text{50}\text{ms}$ has to be calculated.

Concept introduction:

Relaxation is the process by which the magnetization returns to its equilibrium value, at which point it is entirely along the $z-$ axis, with no $x-$ and no $y-$ component (no transverse components).  In practice, due to the limitations in the design of the magnet, the field is not perfectly uniform and is different at different locations in the sample.  The inhomogeneity results in an inhomogeneous broadening of the resonance.  The extent of inhomogeneous broadening is expressed in terms of transverse relaxation time.