extreme narrowing approximation
extreme narrowing approximation
[ek′strēm ′nar·ə·wiŋ ə‚präk·sə′mā·shən] (spectroscopy)
A mathematical approximation in the theory of spectral-line shapes to the effect that the exchange narrowing of a perturbation is complete.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.