In magnetic resonancespectroscopy the longitudinal relaxation time,
is associated with spin-lattice relaxation,
and the transverse relaxation time,
with spin-spin relaxation. The definitions are:
are the components of magnetization parallel and perpendicular to the static field
and the subscript e denotes the equilibrium value.
In a chemical reaction, the time,
, in which a concentration perturbation falls to
of its initial value.
PAC, 1996, 68, 149
(A glossary of terms used in chemical kinetics, including reaction dynamics (IUPAC
on page 185