diffraction ring

diffraction ring

[di′frak·shən ‚riŋ]
(optics)
Circular light pattern which appears to surround particles in a microscope field.
References in periodicals archive ?
Once again, center Polaris in the eyepiece and switch to a high-power eyepiece, magnifying the view enough so that when the star is in focus you can see the Airy disk and the first diffraction ring.
On the diffraction ring of the (300) of [beta]-iPP suffered with vibration treatment, we can clearly see six diffraction arcs, indicating that an evident and strong oriented structure appears.
1) Diffraction ring appearance, where the observer judged the seeing by the appearance and quality of the diffraction rings of highly magnified stellar images, using a small reflecting telescope.
15 mm to minimize the effect of pressure gradients in the pressed sample; (2) an increase in the sample-to-film distance to include a range between 30 mm and 75 mm for improved accuracy in the measurement of diffraction ring diameters; (3) a corresponding increase in film-cassette diameter to 75 mm; (4) a modified entablature containing a wedge cutout to permit the recording of diffraction rings on film to 2[theta] [approximately equal to] 35[degrees].
Melt-crystallized isotropic polymers typically display a strong first-order diffraction ring and one or two higher-order rings of much lower intensity.
The diffraction ring was clearly measured, and this revealed that the organo-clay nanoplatelets just after removing acetone (before starting the curing process), were intercalated and randomly oriented in DGEBA.
Each of its two tight pairs was cleanly split, with tiny Airy disks surrounded by a single diffraction ring and clear dark sky between the component stars.
Ideally, the outer diffraction ring should appear equally bright inside and outside of focus.
The origin of this diffraction ring in the heat-treated sample is not clear.
It's clear from the simulations (shown above) that aberration is barely visible at 1/10[lambda], but becomes obvious at 1/4[lambda], where a significant amount of light has moved to a star's first diffraction ring, resulting in a measurable increase in its FWHM.
I noted occasional glimpses of the first diffraction ring around the Airy disk when observing Albireo (Beta Cygni), particularly around the yellow star of this well-known colorful pair.
The brightest, innermost diffraction ring contains 7.