free induction decay

initialism: FID

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 (\(T_{2}^{*}\)), \(\sin (\omega t) \exp(-t/T_{2}^{*})\).

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)