Conference paper
Simulating the optical performances of the ATHENA X-ray telescope optics
National Institute for Astrophysics1
Astrophysics and Atmospheric Physics, National Space Institute, Technical University of Denmark2
National Space Institute, Technical University of Denmark3
Neutrons and X-rays for Materials Physics, Department of Physics, Technical University of Denmark4
ESTEC5
Media Lario S.r.l.6
The ATHENA (Advanced Telescope for High Energy Astrophysics) X-ray observatory is an ESA-selected L2 class mission. In the proposed configuration, the optical assembly has a diameter of 2.2 m with an effective area of 1.4 m2 at 1 keV, 0.25 m2 at 6 keV, and requires an angular resolution of 5 arcsec.
To meet the requirements of effective area and angular resolution, the technology of Silicon Pore Optics (SPO) was selected for the optics implementation. The ATHENA's optic assembly requires hundreds of SPOs mirror modules (MMs), obtained by stacking wedged and ribbed silicon wafer plates onto silicon mandrels to form the Wolter-I configuration.
Different factors can contribute to limit the imaging performances of SPOs, such as i) diffraction through the pore apertures, ii) plate deformations due to fabrication errors and surface roughness, iii) alignment errors among plates in an MM, and iv) co-focality errors within the MMs assembly. In order to determine the fabrication and assembling tolerances, the impact of these contributions needs to be assessed prior to manufacturing.
A set of simulation tools responding to this need was developed in the framework of the ESA-financed projects SIMPOSIuM and ASPHEA. In this paper, we present the performance simulation obtained for the recently proposed ATHENA configuration in terms of effective area, and we provide a simulation of the diffractive effects in a pair of SPO MMs.
Finally, we present an updated sizing of magnetic diverter (a Halbach array) and the magnetic fields levels that can be reached in order to deviate the most energetic protons out of the detector field.
Language: | English |
---|---|
Publisher: | SPIE - International Society for Optical Engineering |
Year: | 2018 |
Proceedings: | SPIE Astronomical Telescopes and Instrumentation 2018: Ultraviolet to Gamma Ray |
Types: | Conference paper |
DOI: | 10.1117/12.2315019 |
ORCIDs: | Della Monica Ferreira, D. , Knudsen, E. Bergbäck , Christensen, F. E. , Jegers, A. S , Massahi, S. and Westergaard, N. J. |