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Toroidally Shaped Hopg Crystals as Strongly Focusing Bragg Reflectors of Characteristic X-Ray Tube Radiation for Edxrf Analysis

Published online by Cambridge University Press:  06 March 2019

B. Beckhoff
Affiliation:
University of Bremen, Department of Physics, P.O. 330 440 D-28334 Bremen, Germany
B. Kanngieβer
Affiliation:
University of Bremen, Department of Physics, P.O. 330 440 D-28334 Bremen, Germany
J. Scheer
Affiliation:
University of Bremen, Department of Physics, P.O. 330 440 D-28334 Bremen, Germany
W. Swoboda
Affiliation:
University of Bremen, Department of Physics, P.O. 330 440 D-28334 Bremen, Germany
J. Laursen
Affiliation:
Royal Veterinary and Agricultural University Department of Mathematics and Physics DK-1871 Frederiksberg C, Denmark
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Abstract

The characteristic 17.441 keV Mo-Kα tube line yields an exceedingly strong reflection at a Bragg angle of 6.0710 on Highly Oriented Pyrolytic Graphite (IIOPG). Using doubly bent toroidally shaped crystals we were able to concentrate the characteristic radiation from a Mo anode fine focus tube onto a small focal spot area of about 1 mm. FWHM diameter, as was observed by an X-Ray sensitive CCD. The radiation of the Mo anode fine focus tube is emitted at a take-off angle of 60 into a total solid angle with an aperture of 120. About 90 percent of this primary radiation solid angle can be used for the desired Bragg reflection on the designed toroidal crystal surface. This feature ensures the high beam intensity needed for special excitation problems.

Type
Research Article
Copyright
Copyright © International Centre for Diffraction Data 1993

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