  The interest in using the radiation detectors based on high resistive
chromium-compensated GaAs (GaAs:Cr) in high energy physics and others applied
fields has been growing steadily due to its numerous advantages over others
classical materials. High radiation hardness at room temperature stands out and
needs to be systematically investigated. In this paper an experimental study of
the effect of 20.9 MeV electrons generated by the LINAC-200 accelerator on some
properties of GaAs:Cr based sensors is presented. In parallel, Si sensors were
irradiated at the same conditions, measured and analyzed in order to perform a
comparative study. The target sensors were irradiated with the dose up to 1.5
MGy. The current-voltage characteristics, resistivity, charge collection
efficiency and their dependences on the bias voltage and temperature were
measured at different absorbed doses. An analysis of the possible microscopic
mechanisms leading to the observed effects in GaAs:Cr sensors is presented in
the article.
