X-ray testing at PANTER of optics for the ATHENA and Arcus Missions

Abstract

Currently for the European Space Agency (ESA) ATHENA [1,2] mission Silicon Pore Optic (SPO) [3][4][5][6][7][8] Mirror Modules (MM) with a focal length of f = 12 m, are being developed and tested. The SPO MMs are also the baseline optic for the NASA medium explorer high-resolution spectroscopy mission Arcus [9-10] with f = 12 m that is currently undergoing a phase A study. SPOs are currently being tested at both the PTB laboratory of the BESSY synchrotron facility in Berlin using an X-ray pencil beam and the PANTER X-ray test facility in Neuried of the Max-Planck-Institut für extraterrestrische Physik, Garching using a long vacuum beamline (distance source to optic ~120 m). The different types of measurements performed at PANTER to characterise the ATHENA and Arcus optics will be discussed. This will be done on the level of an X-ray optical unit (XOU) composed of both a primary and secondary High Performance Optic (HPO) stack, a mirror module (MM) composed of two XOUs, small (<4 MMs) and large (< 25 MM) petals, and the complete integrated optic Athena (700-1000 MMs) and Arcus (4 petals each with 38 MMs). The main set of tests that are currently done at PANTER make full use the possibility to fully-illuminate single XOUs, MMs, and petals to determine their optical characteristics such as the half energy width of the point spread function as well as the effective area and the vignetting function at different energies. To ensure that the measurements, that are required to demonstrate the performance of ATHENA, are possible, a description of recent and upcoming upgrades to the PANTER X-ray test facility will be given. Finally, a status update on the progress on designing the new facility to be used to test and calibrate the complete ATHENA mirror will be presented.

Testing ATHENA optics: a new measurement standard at the PANTER x-ray test facility

“…The test method for this optic followed the same method as previous ATHENA MM test campaigns at PANTER 4,6 . As such, only a brief description is given here.…”

Silicon Pore Optics

“…The need to comply with the tight verification/calibration requirements for the Athena MA is a major challenge, due to its large size. In order to ensure that the uncertainties due to the divergence of the beam are compatible with the accuracy requirements of the calibrations, the source should be positioned at a minimum distance of 300 m. Since the largest X-ray calibration facility in Europe is the MPE Panter facility with a 120 m vacuum tube [8], this requirement can only be satisfied with either the NASA X-ray & Cryogenic Facility [34] or a new concept for an X-ray facility, the VERT-X facility [50]. Both of these (Bottom) Very good agreement between the centroid of the PSF obtained with UV and X-ray illumination (X-ray curve obtained at the PANTER facility, and UV curve obtained with UV facility [61].…”

The Athena x-ray optics development and accommodation

“…The Panter facility [40] (figure 11 mid left) operated by the Max Plack Gesellschaft near Munich in Ge rmany will continue to be used as a classic test facility with a long beamline of 130 m providing large area sampling.…”