Webster's Revised Unabridged Dictionary (1913)
The deflection and decomposition of light in passing by the edges of opaque bodies or through narrow slits, causing the appearance of parallel bands or fringes of prismatic colors, as by the action of a grating of fine lines or bars.
Webster's Revised Unabridged Dictionary (1913), edited by Noah Porter. About
hEnglish - advanced version
\dif*frac"tion\ (?), n. [cf. f. diffraction.] (opt.) the deflection and decomposition of light in passing by the edges of opaque bodies or through narrow slits, causing the appearance of parallel bands or fringes of prismatic colors, as by the action of a grating of fine lines or bars. remarked by grimaldi (1665), and referred by him to a property of light which he called diffraction.
grating. (optics) see under grating.
spectrum. (optics) see under spectrum.
Telecommunication Standard Terms
The deviation of an electromagnetic wavefront from the path predicted by geometric optics when the wavefront interacts with, i.e. , is restricted by, a physical object such as an opening (aperture) or an edge. (188 ) Note: Diffraction is usually most noticeable for openings of the order of a wavelength. However, diffraction may still be important for apertures many orders of magnitude larger than the wavelength.
The process whereby RF signals or sound waves are, in certain circumstances, deflected from their normal straight-line path by physical objects.
The result of light waves interfering with other after passing through a narrow aperture, causing them to bend or spread.
Powder X-ray Diffraction (XRD) is one of the primary techniques used by mineralogists and solid state chemists to examine the physico-chemical make-up of unknown solids. This data is represented in a collection of single-phase X-ray powder diffraction patterns for the three most intense D values in the form of tables of interplanar spacings (D), relative intensities (I/Io), and mineral name.
The XRD technique takes a sample of the material and places a powdered sample in a holder, then the sample is illuminated with x-rays of a fixed wave-length and the intensity of the reflected radiation is recorded using a goniometer. This data is then analyzed for the reflection angle to calculate the inter-atomic spacing (D value in Angstrom units - 10-8 cm). The intensity(I) is measured to discriminate(using I ratios) the various D spacings and the results are to identify possible matches.