Dr. Jaromir Hrdy Profile

Dr. Jaromir Hrdy

Senior Scientist at Institute of Physics of the ASCR vvi

SPIE Involvement:

Author

Proceedings Article | 23 December 2003 Paper

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

Nikolay Artemiev, Jaromir Hrdy, Thierry Bigault, Joanna Hoszowska, Sergey Peredkov

Proceedings Volume 5195, (2003) https://doi.org/10.1117/12.504730

KEYWORDS: Crystals, Surface finishing, X-rays, X-ray diffraction, Reflectivity, Diffraction, Polishing, Silicon, Monochromators, Manufacturing

Read Abstract +

Proceedings Article | 23 December 2003 Paper

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

Jaromira Hrda, Jaromir Hrdy, Olivier Hignette, Joanna Hoszowska

Proceedings Volume 5195, (2003) https://doi.org/10.1117/12.505553

KEYWORDS: Crystals, Surface finishing, Diffraction, Laser crystals, Polishing, X-rays, X-ray diffraction, Silicon, Monochromators, Etching

Read Abstract +

Proceedings Article | 23 December 2003 Paper

Dynamic focusing of polychromatic incident beam with bent crystals in Laue geometry

Vito Mocella, Jean-Pierre Guigay, Jaromir Hrdy, Claudio Ferrero, Joanna Hoszowska

Proceedings Volume 5195, (2003) https://doi.org/10.1117/12.505058

KEYWORDS: Crystals, Laser crystals, Diffraction, X-ray optics, Absorption, Reflection, Wave propagation, Optical fiber cables, Refraction, Lenses

Read Abstract +

In the hard x-ray range, optics based only on refraction, as in the case of visible optics, require extremely small (a few microns) bending radii of the crystal monochromators, since the deviation of the refraction index (δ = 1-n) from unity is of the order of 10^-6. Based on the principle of a series of N refractive lenses, compound refractive lenses provide an appreciable focus at a reasonable distance, but the photon flux is limited by absorption because of the generally high value of N required. As the effect of refraction is very weak, x-rays deviate considerably when diffraction occurs in a crystal in Bragg geometry: this is the base of many crystal optics devices. Focusing with crystal optics is generally achieved bending the crystals to modify the orientation of the lattices planes or modulating the entrance surface of a flat or curved crystal, the so-called Bragg-Fresnel lens. Sagittal focusing can be also obtained using asymmetrically cut crystals. From a general point of view the focusing by means of bent crystals in Laue geometry is interesting when high energies are used, because the absorption due to the transmission in the crystals is very limited. The use of bent crystals has two big advantages: it allows to accept a great divergence of the incoming radiation, thus increasing the flux of the focused radiation and allowing at the same time to select its frequencies, owing to the Darwin width of the considered reflection. Indeed, the crystal bending enables the diffracting planes to be crossed at the Bragg angle corresponding to each ray of the incident beam and, at the same time, the diffraction process produces a monochromatic beam. Actually, a small Bragg angle implies a rather long beam path in the crystal in the case of Bragg geometry, whereas in Laue geometry the incidence is almost normal: the absorption is therefore minimized upon using a suitably thin crystal. We suggest here a method allowing to improve the quality of high energy polychromatic focusing by bent crystals in Laue geometry.

Proceedings Article | 14 November 2001 Paper

Diffractive-refractive optics for focusing hard x-ray beams

Jaromir Hrdy, Nikolai Artemiev, Andreas Freund, John Quintana

Proceedings Volume 4501, (2001) https://doi.org/10.1117/12.448481

KEYWORDS: Crystals, Diffraction, Laser crystals, Monochromators, X-rays, X-ray diffraction, Refraction, Hard x-rays, Single crystal X-ray diffraction, X-ray optics

Read Abstract +

Proceedings Article | 7 March 2001 Paper

Equipment for measurement of the granularity of photographic materials

Jaromir Hrdy, Jaroslav Pospisil

Proceedings Volume 4356, (2001) https://doi.org/10.1117/12.417865

KEYWORDS: Photography, Digital signal processing, Signal processing, Transmittance, Computing systems, Image transmission, Mechanical engineering, Digital photography, Image registration, Visualization

Read Abstract +

Conference Committee Involvement (1)

Crystals, Multilayers, and Other Synchrotron Optics

5 August 2003 | San Diego, California, United States

Keywords/Phrases

Search In:

Publication Years