Impact ofionizing radiations on ZERODUR®

摘要

Satellites operating on LEO and GEO trajectories are subject to the effect of ionizing space radiations, mostly electrons, that are concentrated in the Van Allen belts These ionizing radiations are responsible for accelerated ageing (especially compaction, i.e. local material density variation), which is thought to be detrimental for the optical figure of the embedded optical devices. The studies made on this topic during the last four decades, are proposing very different phenomenological power laws description of this effect. However, the simulated deformations derived from these laws are in partial disagreement with the observations made at the laboratory, moreover they do not account for the absence of problems reported during the space missions embedding ZERODUR® material. In order to elucidate these mismatches, we defined a new experimental approach suited for the description of the compaction phenomenon for doses corresponding to typical astrospace missions. An overview of the preparatory simulation work for the design of the irradiation environment, for the design of the build-up shielding material as well as of the design of the target samples will be presented. This study will also give a short description of the experimental irradiations sequence as well as the high precision metrological approaches used in order to determine the changes induced in the ZERODUR®.