Rowlandn.
/ˈrəʊlənd/, U.S. /ˈroʊlən(d)/ Physics.
1.
a. Rowland grating n. (also Rowland's grating) a diffraction grating ruled on a concave mirror surface, which collimates and focuses incident light.
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the world > matter > physics > electromagnetic radiation > light > diffraction > [noun] > apparatus
Rowland grating1882
1882 Ann. Rep. Indiana Univ. 1881–2 81 A Borda pendulum, thermometers, barometers, thermopile, Rowland grating, [etc.].
1904 London, Edinb., & Dublin Philos. Mag. 6th Ser. 7 460 The first-order spectrum of a Rowland's grating.
1910 London, Edinb., & Dublin Philos. Mag. 6th Ser. 20 773 I had a polished flat plate of speculum metal, such as is used for making Rowland gratings, silver-plated and polished.
1974 Encycl. Brit. Macropædia II. 235/1 Some Rowland gratings are still in use.
2006 T. Arabatzis Representing Electrons iv. 75 The absorption spectrum was obtained by means of the Rowland grating.
b. Rowland mounting n. (also Rowland's mounting) a mounting for a spectrograph with a Rowland grating in which the grating and detector are connected by a bar forming the diameter of the Rowland circle.
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the world > matter > physics > electromagnetic radiation > light > chromatism > [noun] > spectrum > instrument for examining > arrangement
Rowland mounting1895
Rowland circle1902
1895 Astrophysical Jrnl. 2 380 The positions of the slit and eyepiece are simply interchanged in an ordinary Rowland mounting.
1901 Physical Rev. 12 10 The second grating..was of 21 ft. radius, 14,438 lines to the inch. It was arranged on Rowland's mounting.
1914 Astrophysical Jrnl. 40 205 It provides for a grating of 15 ft. (4·57 m) radius, and, optically considered, is the Rowland mounting with the plane of the focal circle vertical.
1955 Vistas in Astron. 1 433 The Eagle mounting has the advantage..of being less affected by astigmatism than, say, the Rowland mounting.
2007 J. F. James Spectrograph Design Fund. ix. 94 In common with the Rowland mounting this uses the angle-in-a-semicircle theorem.
c. Rowland circle n. (also Rowland's circle) a circle on which the slit, (concave) diffraction grating, and detector of a spectrograph must all lie if all the spectral lines are to be brought to a focus on the detector.The circle has a diameter equal to the radius of curvature of the grating surface and is tangential to the grating at its midpoint.
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the world > matter > physics > atomic physics > decomposition of light, spectrum > study of spectra > [noun] > instrument used in > part of
Rowland circle1902
the world > matter > physics > electromagnetic radiation > light > chromatism > [noun] > spectrum > instrument for examining > arrangement
Rowland mounting1895
Rowland circle1902
1902 Astrophysical Jrnl. 15 236 In adjusting the grating we found that the spectrum by no means fell on the ‘Rowland circle’ passing through the slit, the grating and the center of curvature.
1967 G. W. Stroke in S. Flugge Handbuch der Physik XXIX. 477 Eq. (25.27) is clearly satisfied on Rowland's circle.
2007 G. Zschornack Handbk. X-ray Data iii. 135 A reduction of the influence of geometrical effects on wavelength shifts can be achieved by an increase of the diameter of the Rowland circle.
d. Rowland ghost n. (also Rowland's ghost) a spurious spectral line produced by a periodic error in the spacing of the lines of a diffraction grating. Cf. ghost n. 17b.
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the world > matter > physics > electromagnetic radiation > light > diffraction > [noun] > apparatus > error in
Rowland ghost1922
1922 Jrnl. Optical Soc. Amer. 6 419 The separations of the Rowland ghosts from the parent lines are readily deduced from the characteristics of the ruling engine.
1975 Jrnl. Molecular Spectrosc. 54 183 A very strong pattern of Rowland's ghosts overlapping the Raman spectrum.
1997 E. G. Loewen & E. Popov Diffraction Gratings & Applic. xi. 402 It is rare today to find a grating whose performance is seriously compromised by the presence of Rowland ghosts.
2. Rowland ring n. a ring-shaped sample of a magnetic material enclosed within a coil of current-carrying wire, typically used in finding the magnetization curve of that material.
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the world > matter > physics > electromagnetic radiation > electricity > electrically induced magnetism > [noun] > torus to be investigated
Rowland ring1904
the world > matter > physics > electromagnetic radiation > magnetism > magnetic devices or materials > [noun] > magnetic torus
Rowland ring1904
1904 Proc. Amer. Soc. Testing Materials 4 180 It appears also that the Rowland ring method is that most commonly used in connection with the galvanometer.
1966 McGraw-Hill Encycl. Sci. & Technol. (rev. ed.) VIII. 51/1 When the core of the Rowland ring is initially demagnetized, B = 0 and H = 0.
1994 Physics Educ. 29 104/2 The measurement of the magnetic permeabilities of such materials would require a more specific experimental set-up (e.g. a Rowland ring).
This entry has been updated (OED Third Edition, March 2011; most recently modified version published online March 2022).
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n.1882