full width at half maximum


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full width at half maximum

[′fu̇l ‚width at ′haf ′mak·sə·məm]
(physics)
The difference between the energies or frequencies on either side of a spectral line or resonance curve at which the line absorption or emission or the resonant quantity reaches half its maximum intensity. Abbreviated FWHM.
References in periodicals archive ?
Generally, the full width at half maximum is used to evaluate Gaussian function instead of its standard deviation.
One way of quantitatively expressing the spread of specific gravities is to measure the full width at half maximum (FWHM) values for the major peak in frequency.
By taking spectra in transmittance between 2650 and 3350 |cm.sup.-1~, we can examine the alkyl stretching region of the spectrum for the peak position and width (full width at half maximum, or FWHM) of the octadecyl group absorbances.
The corresponding (002) peak location and full width at half maximum of X-ray diffraction spectra are listed in Table 1.AfterTDS being measured, the (002) peak shifts to a lower angle for all AZO films.
The mosaic spread of this crystal can be made large enough ([approximately equal to]2[degrees] full width at half maximum) to match the neutron guide divergence so that all of the neutrons that can efficiently produce UCNs UCNs in [.sup.4]He by one-phonon down scattering are reflec-reflected.