Efficiency measurements and simulations of a HAPG based Von Hamos spectrometer for large sources

Journal of Analytical Atomic Spectrometry ◽

10.1039/d1ja00214g ◽

2021 ◽

Author(s):

Alessandro Scordo ◽

Veronica De Leo ◽

Catalina Curceanu ◽

Marco Miliucci ◽

Florin Sirghi

Keyword(s):

Ray Tracing ◽

Mosaic Crystals

In this paper we report about the reflection efficiency measurements of the VOXES Von Hamos (VH) spectrometer, based on HAPG mosaic crystals, together with the ray tracing simulations results. Von...

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A new model for the description of X-ray diffraction from mosaic crystals for ray-tracing calculations

Journal of Applied Crystallography ◽

10.1107/s1600576717012626 ◽

2017 ◽

Vol 50 (5) ◽

pp. 1490-1497 ◽

Cited By ~ 2

Author(s):

Christopher Schlesiger ◽

Lars Anklamm ◽

Wolfgang Malzer ◽

Richard Gnewkow ◽

Birgit Kanngießer

Keyword(s):

Ray Tracing ◽

X Ray Diffraction ◽

Multiple Reflections ◽

New Model ◽

X Ray ◽

Additional Information ◽

Diffraction Model ◽

Reflection Model ◽

Mosaic Crystals ◽

Ray Tracing Simulation

This paper presents the development of a new reflection model for describing X-ray diffraction from mosaic crystals. In contrast to the well established diffraction model of Zachariasen [Zachariasen (1994),Theory of X-ray Diffraction in Crystals. Mineola: Dover Publications], it gives additional information on the spatial reflection behaviour and not just on the depth-integrated reflectivity of the crystal material. The new reflection model enables a concrete description of mosaic crystal performance in an arbitrary X-ray spectrometer configuration. Multiple reflections inside the crystal are described by splitting the calculation into a discrete number of reflections. Hence, the influence of each number of reflections is investigated, leading to a laterally resolved solution for the reflectivity. In addition, the model can use a mosaicity of arbitrary shape. This is important because the present work uses a Lorentzian-shaped mosaicity instead of a Gaussian one, which is usually the case in the most widely used simulation programs. A comparison between the new model and that of Zachariasen is performed, and it predicts a similar integrated reflectivity with a deviation lower than 0.7%. Further, a ray-tracing simulation with multiple reflections based on the new model is compared with a measurement, showing a deviation of lower than 5%.

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A conceptual model for ray tracing calculations with mosaic crystals

Review of Scientific Instruments ◽

10.1063/1.1143784 ◽

1992 ◽

Vol 63 (1) ◽

pp. 932-935 ◽

Cited By ~ 17

Author(s):

M. Sánchez del Río ◽

S. Bernstorff ◽

A. Savoia ◽

F. Cerrina

Keyword(s):

Conceptual Model ◽

Ray Tracing ◽

Mosaic Crystals

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Reflection Efficiency and Spectra Resolutions Ray-Tracing Simulations for the VOXES HAPG Crystal Based Von Hamos Spectrometer

Condensed Matter ◽

10.3390/condmat7010001 ◽

2021 ◽

Vol 7 (1) ◽

pp. 1

Author(s):

Veronica De Leo ◽

Alessandro Scordo ◽

Catalina Curceanu ◽

Marco Miliucci ◽

Florin Sirghi

Keyword(s):

High Resolution ◽

Ray Tracing ◽

Collection Efficiency ◽

Pyrolytic Graphite ◽

X Ray ◽

Simulation Procedure ◽

Signal Collection ◽

Standard Calibration ◽

Mosaic Crystals ◽

Ray Tracing Simulation

The VOXES collaboration at INFN National Laboratories of Frascati developed a prototype of a high resolution Von Hamos X-ray spectrometer using HAPG (Highly Annealed Pyrolytic Graphite) mosaic crystals. This technology allows the employment of extended isotropic sources and could find application in several physics fields. The capability of the spectrometer to reach energy precision and resolution below 1 and 10 eV, respectively, when used with wide sources, has been already demonstrated. Recently, the response of this device, for a ρ = 206.7 mm cylindrically bent HAPG crystal using CuKα1,2 and FeKα1,2 XRF lines, has been investigated in terms of reflection efficiency by a dedicated ray-tracing simulation. Details of the simulation procedure and the comparison with the experimental results are presented. This study is crucial in order to retrieve information on the spectrometer signal collection efficiency, especially in the energy range in which the standard calibration procedures cannot be applied.

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