Characterization of bent crystals for Laue lenses

TL;DR

This paper evaluates bent crystal reflectivity for Laue lenses in gamma-ray astronomy, aiming to optimize materials and configurations to significantly enhance telescope sensitivity and imaging capabilities.

Contribution

It provides experimental data on bent crystal reflectivity, comparing perfect, mosaic, and flat crystals, to optimize Laue lens design for high-energy gamma-ray astronomy.

Findings

Bent crystals show promising reflectivity for Laue lens applications.

Optimal crystal thickness and material depend on specific configurations.

Results suggest potential for at least 100-fold sensitivity improvement.

Abstract

In the context of the LAUE project devoted to build a long focal-length focusing optics for soft $\gamma$-ray astronomy (80 - 600 keV), we present the results of reflectivity measurements of bent crystals in different configurations, obtained by bending perfect or mosaic flat crystals. We also compare these results with those obtained using flat crystals. The measurements were performed using the K$\alpha$ line of the Tungsten anode of the X-ray tube used in the LARIX facility of the University of Ferrara. These results are finalized to select the best materials and to optimize the thickness of the crystal tiles that will be used for building a Laue lens petal which is a part of an entire Laue lens, with 20 m focal length and 100-300 keV passband. The final goal of the LAUE project is overcome, by at least 2 orders of magnitude, the sensitivity limits of the current generation of $\gamma$-ray telescopes, and to improve the current $\gamma$-ray imaging capability.