Properties of GaAs:Cr-based Timepix detectors

摘要

It is the hybrid pixel detector technology which brought to the X-ray imaginga low noise level at a high spatial resolution, thanks to the single photoncounting. However, silicon as the most widespread detector material ismarginally sensitive to photons with energy more than 30 keV. That's why thehigh-Z alternatives to silicon such as gallium arsenide and cadmium tellurideare increasingly attracting attention of the community for the development ofX-ray imaging systems in recent years. We present in this work the results ofour investigations of the Timepix detectors bump-bonded with sensors made ofgallium arsenide compensated by chromium (GaAs:Cr). The properties which aremostly important from the practical point of view: IV characteristics, chargetransport characteristics, operational stability, homogeneity, temperaturedependence as well as energy and spatial resolution are considered.Applicability of these detectors for spectroscopic X-ray imaging is discussed.