Advanced Manufacturing Techniques for High Precision X- Ray Optics and New Technology Spin-Offs

摘要

Focusing mirrors manufactured via galvanic replication process from negative shape mandrels is the selected solution for the approved X-ray astronomy mission eROSITA and the candidate solution for some of the next future X-ray astronomy missions. Media Lario Technologies (MLT) is the industrial enabler for manufacturing (in collaboration with the Max Planck Institute (MPE) and the German Space Agency (DLR)) of the Optical Payload for eROSITA - including the flight quality mandrels. Media Lario Technologies (MLT) is also now developing, in collaboration with Brera Astronomical Observatory (INAF/OAB), the Optical Payload for the New Hard X-ray Mission (NHXM). For the eROSITA mandrels production an evolution of the approach used for the manufacturing of past mission mandrels (JET-X, XMM) have been developed. The low energy angular resolution of the eROSITA mirror payload needs to be 15 arcsec HEW or better; and at 8.05keV the angular resolution needs to be 20 arcsec HEW or better. Replicated mirrors with performance in this range for the low energy radiation have been obtained in the past by using mandrels that have superior geometrical shape accuracy. A proprietary multistep surface finishing process has now been developed for reaching the aggressive performance requirements demanded by the mission. The status of the eROSITA series mandrels manufactured so far, by using the advanced polishing process, are presented. In the paper, the x-ray performance of mirror shells (as measured at MPE PANTER facility) replicated from a flight quality eROSITA mandrel, are reported.