Indication from a pulsed spectroscopy experiment that takes the form of damped sine waves arising from the excited system returning to equilibrium.
Note: In
nuclear magnetic resonance spectroscopy, the FID consists of sine waves oscillating at the Larmor frequency (
\(\omega\)) and dampened by net dephasing time relaxation (
\(T_{2}^{*}\)),
\(\sin (\omega t) \exp(-t/T_{2}^{*})\).
Source:
PAC, 2021, 93, 647. 'Glossary of methods and terms used in analytical spectroscopy (IUPAC Recommendations 2019)' on page 659 (https://doi.org/10.1515/pac-2019-0203)