Sagittally focusing diffractive-refractive x-ray lens with a large acceptance and a long focusing distance

Artemiev, Nikolay A.; Hrdý, J.; Bigault, T.; Hoszowska, J.; Peredkov, S.

doi:10.1117/12.504730

Cited by 6 publications

(2 citation statements)

References 5 publications

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“…Diffractive-refractive optics [1][2][3][4][5][6][7][8] is based on the deviation of diffracted beam due to the deviation of the crystal surface with respect to diffracting crystallographic planes. It was shown that a parabolic longitudinal groove produced into the surface of symmetrically or asymmetrically cut crystal may focus x-ray synchrotron radiation sagittally [1][2][3][4][5][6] and a properly designed transversal groove may focus the radiation meridionally [7,8]. There are various factors, which can influence the sharpness of the focus.…”

Section: Introductionmentioning

confidence: 99%

Influence of the crystal-surface unevenness on the angular spread of an x-ray diffracted beam

Hrdá¹,

Potlovskiy²,

Hrdý³

et al. 2005

J. Phys. D: Appl. Phys.

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One of the factors influencing the focus size in diffractive–refractive optics is the quality of diffracting surface. If the surface is uneven, as it is when the silicon crystal surface is only etched, then the diffraction at each point of the surface is a combination of an asymmetric and inclined diffraction (general asymmetric diffraction). This somewhat deviates and spreads the diffracted beam. The integration over the surface hit by an incident beam gives the angular spread of the diffracted beam. It is shown theoretically that in some cases (highly asymmetric, highly inclined cut) the etched surface may create the spread of the diffracted beam such that it causes a significant broadening of the focus. In this case a mechanical–chemical polishing is necessary. This has been verified by us earlier in a preliminary experiment with synchrotron radiation. In this work the new experiment with the same crystals is performed using double crystal (+, −) arrangement and a laboratory x-ray source (CuKα radiation). We compared two samples; one of them is mechanically–chemically (MC) polished and thus the diffracting surface is almost perfect; the other is only etched. This experiment allows a better comparison of the result with the theory. The difference between the measured rocking curve widths for the etched and MC polished crystals (10″) roughly agrees with theory (7″), which supports the correctness of the theoretical approach.

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Section: Introductionmentioning

confidence: 99%

Influence of the crystal-surface unevenness on the angular spread of an x-ray diffracted beam

Hrdá¹,

Potlovskiy²,

Hrdý³

et al. 2005

J. Phys. D: Appl. Phys.

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“…Most studies focused on the Bragg diffraction case, both symmetric and asymmetric [3,11]. It was shown that this effect may be utilized to sagittaly focus the diffracted radiation if the diffraction surface is profiled into a parabolic groove [1,2,5,6,8 ]. Technical reasons forced us to approximate the parabolic groove into a circular one.…”

mentioning

confidence: 99%

Highly asymmetric Laue focusing monochromator

Oberta¹,

Mikulı́k²,

Hrdý³

et al. 2010

AIP Conference Proceedings

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By using two highly asymmetric Laue crystals in a dispersive arrangement with a circular profile (∅ 8 mm) we have created a sagittaly focusing Laue system for the first time. The crystallographic planes (111) of the two Si crystals formed an angle of 7.95° with the entrance surface. The crystals dimensions were 40 mm × 20 mm and the diffracting surface was a 0.5 mm thick neck between the two circular profiles. The 15.35 keV diffracted beam formed an angle of 0.55° with the exit surface. The calculated focusing distance of the Laue-Laue focusing system was 14 m.

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Diffractive-Refractive Optics: X-ray Crystal Monochromators with Profiled Diffracting Surfaces

Hrdý

Hrdá

Springer Series in Optical Science

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Sagittally focusing diffractive-refractive x-ray lens with a large acceptance and a long focusing distance

Cited by 6 publications

References 5 publications

Influence of the crystal-surface unevenness on the angular spread of an x-ray diffracted beam

Influence of the crystal-surface unevenness on the angular spread of an x-ray diffracted beam

Highly asymmetric Laue focusing monochromator

Diffractive-Refractive Optics: X-ray Crystal Monochromators with Profiled Diffracting Surfaces

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