  The characteristics of a hydrogenated amorphous silicon (a-Si:H) detector are
presented here for monitoring in space solar flares and the evolution of large
energetic proton events up to hundreds of MeV. The a-Si:H presents an excellent
radiation hardness and finds application in harsh radiation environments for
medical purposes, for particle beam characterization and in space weather
science and applications. The critical flux detection threshold for solar X
rays, soft gamma rays, electrons and protons is discussed in detail.
