Optical design and performance simulations for the 1.49 keV beamline of the BEaTriX X-ray facility

Abstract

The BEaTriX (Beam Expander Testing X-ray) facility, now operational at INAF-Brera Astronomical Observatory, will represent a cornerstone in the acceptance roadmap of Silicon Pore Optics (SPO) mirror modules, and will so contribute to the final angular resolution of the ATHENA X-ray telescope. By expansion and collimation of a microfocus X-ray source via a paraboloidal mirror, a monochromation stage, and an asymmetric crystal, BEaTriX enables the full-aperture illumination of an SPO mirror module with a parallel, monochromatic, and broad (140 mm × 60 mm) X-ray beam. The beam then propagates in a 12 m vacuum range to image the point spread function of the mirror module, directly on a focal plane camera. Currently the 4.51 keV beamline, based on silicon crystals, is operational in BEaTriX. A second beamline at 1.49 keV, which requires a separate paraboloidal mirror and organic crystals (ADP) for beam expansion, is being realized. As for monochromators, the current design is based on asymmetric quartz crystals. In this paper, we show the current optical design of the 1.49 keV beamline and the optical simulations carried out to predict the achievable performances in terms of beam collimation, intensity, and uniformity. In the next future, the simulation activity will allow us to determine manufacturing and alignment tolerances for the optical components.

The expanded, parallel, and monochromatic x-ray beam of BEaTriX: alignment and characterization

“…The alignment procedure was a complex and long phase of the BEaTriX commissioning [22] involving different instruments and several ad-hoc setups, which required constrains on the design of the facility. An X-ray beam in line with the expectations was obtained [23] . The lessons learnt can be used in future for the second beam line (1.49 keV) to improve and also ease the alignment procedures.…”