https://doi.org/10.1351/goldbook.08249
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 angular frequency (\(\omega\)) and dampened by net dephasing time relaxation (\(T_{2}^{*}\)), \(\sin (\omega t) \exp(-t/T_{2}^{*})\).