Alignment and integration of the SPO mirror modules onto the ATHENA Telescope

Abstract

Several hundreds of Silicon Pore Optics (SPO) mirror modules will be integrated and co-aligned onto the ATHENA (Advanced Telescope for High-ENergy Astrophysics) Mirror Assembly Module (MAM). The integration process has been developed by Media Lario and exploits a full-size optical bench to capture the focal plane image of each mirror module when illuminated by an UV plane wavefront at 218 nm. Each mirror module, handled by a manipulator, focuses the collimated beam onto a CCD camera placed at the 12 m focal position of the ATHENA telescope. The image is processed in real time to calculate the centroid position and overlap it to the centroid of the already integrated Mirror modules. Media Lario with ESA support has designed the Assembly Integration and Test (AIT) facility, able to host the complete ATHENA telescope. The AIT facility is in construction and the 2.6 m Zerodur® parabolic mirror has been accepted for coating and ready to be delivered to Calar Alto Observatory (CAHA, Sierra de Los Filabres, Spain) for the reflective coating application. The building housing the AIT facility is under construction at the Media Lario premises near Milan, Italy, and extends 6.5 m below ground and 17 m above ground. The building also is dimensioned to accommodate the vertical X-ray (Vert-X) test facility. The co-location of these two facilities is strategic for the project and will permit regular checks of the mirror module alignment while the MAM is populated. The MAM will be moved on a rail system connecting the two facilities.