The effects of hyper-velocity dust-particle impacts on the LOFT Silicon Drift Detectors

Solid-state detectors that operate in orbit are required to withstand harsh space environment conditions. Among the various phenomena able to damage the sensors, X-ray detectors are subjected to impacts of orbital debris and micrometeoroids whenever, to be sensitive to low energy photons, they need to be "directly" exposed to the sky. The LOFT mission, proposed for the M3 class opportunity of the ESA Cosmic Vision, has a very-large sensitive area (greater than 10 m(2)) made of Silicon Drift Detectors (SDD). Moreover, the satellite includes an X-ray Wide-Field Monitor based on the same SDD detectors. Here we present the results of a test campaign at the Cosmic Dust Accelerator Facility at MPIK in Heidelberg aimed at the space qualification of the detectors with respect to this phenomenon.