Calibration of the ART-XC mirror modules at MSFC
Abstract
The Astronomical Röntgen Telescope X-ray Concentrator (ART-XC) is a hard X-ray telescope with energy response up to 30 keV, to be launched on board the Spectrum Röntgen Gamma (SRG) spacecraft in 2018. ART-XC consists of seven identical co-aligned mirror modules. Each mirror assembly is coupled with a CdTe double-sided strip (DSS) focal-plane detector. Eight X-ray mirror modules (seven flight and one spare units) for ART-XC were developed and fabricated at the Marshall Space Flight Center (MSFC), NASA, USA. We present results of testing procedures performed with an X-ray beam facility at MSFC to calibrate the point spread function (PSF) of the mirror modules. The shape of the PSF was measured with a high-resolution CCD camera installed in the focal plane with defocusing of 7 mm, as required by the ART-XC design. For each module, we performed a parametrization of the PSF at various angular distances Θ. We used a King function to approximate the radial profile of the near on-axis PSF (Θ < 9 arcmin) and an ellipse fitting procedure to describe the morphology of the far off-axis angular response (9 < Θ < 24 arcmin). We found a good agreement between the seven ART-XC flight mirror modules at the level of 10%. The on-axis angular resolution of the ART-XC optics varies between 27 and 33 arcsec (half-power diameter), except for the spare module.
- Publication:
-
Experimental Astronomy
- Pub Date:
- October 2017
- DOI:
- 10.1007/s10686-017-9555-0
- arXiv:
- arXiv:1708.09783
- Bibcode:
- 2017ExA....44..147K
- Keywords:
-
- X-ray astrophysics;
- Instrumentation:X-ray optics;
- Astrophysics - Instrumentation and Methods for Astrophysics
- E-Print:
- 16 pages, 10 figures, 5 tables, Accepted in Experimental Astronomy