In-flight proton-induced radiation damage to SCIAMACHY’s extended-wavelength InGaAs near-infrared detectors

The performance of the SCIAMACHY detectors has been monitored since launch. Only minor degradation of the silicon-based UV–Vis detectors and the lattice-matched InGaAs NIR detector is observed. The degradation of the NIR extended-wavelength InGaAs detector arrays, however, which are used for the first time in a space-based remote sensing application, is unexpectedly large. The degradation of individual detector pixels is abrupt and mostly leads to excessively high (spread in) dark current. Evidence is presented that non-ionizing radiation due to trapped-protons leads to displacement damage to the InGaAs detector material. The current degradation rate leads to a loss of approximately 50 out of 1024 pixels per channel per year.