ATHENA Telescope: alignment and integration of SPO mirror modules

Abstract

ATHENA (Advanced Telescope for High-ENergy Astrophysics) is the next high-energy astrophysical mission of the European Space Agency currently planned to be launched in the early 2030s, as part of its Cosmic Vision program, on the scientific topic of "Hot and Energetic Universe". The optics technology is based on the Silicon Pore Optics (SPO). About 678 SPO mirror modules will have to be integrated and co-aligned onto the optical bench of the Mirror Assembly Module (MAM) of ATHENA. This activity will have to be completed in about two years. Media Lario leads an industrial and scientific team that has developed the process to align and integrate the SPO Mirror module with an accuracy better than 1 arcsec. The process is based on position of the centroid of the point spread function produced by each mirror module when illuminated by a collimated planewave at 218 nm taken at 12 m focal length. Experimental tests, using two SPO mirror modules, and correlation with X-ray measurement at the PANTER test facility in Münich have demonstrated that this process meets the accuracy requirement. It was also demonstrated, that a mirror module can be removed again from the MAM, and re-installed, without compromising the adjacent mirror modules. This technique allows arbitrary integration sequence and integration of two Mirror Modules per day. Moreover, it enables monitoring the telescope point spread function during the whole integration phase.

The Athena x-ray optics development and accommodation

“…The 600 mirror modules must be accurately co-aligned to focus onto the same spot in the focal place. The required A IT (Assembly Integration and Testing) process has been developed [32][33][34] and demonstrated to exceed the required performance.…”

X-ray mirror development and production for the Athena telescope

“…For Athena a total of about 150.000 such mirrors will have to be produced and turned into 600 mirror modules, an effort that requires a high degree of automation to remain within reasonable cost and time budgets [7]. The 600 mirror modules are then integrated and co-aligned [8] into a large 2.5 m diameter structure to form the final optic.…”