Towards fast transition radiation imaging detectors with CsI converters

The authors present an X-ray imaging method with a potential application to ultrarelativistic particle identification by transition radiation detection. It is based on the conversion of the X-ray photons in a thin layer of CsI and the amplification of secondary emitted electrons in a low-pressure multistep avalanche electron multiplier. The advantages of the solid X-ray converter are the parallax-free imaging and the ultrafast response. The detector had an X-ray localization resolution accuracy better than 0.2 mm, a subnanosecond time response, and a reduced sensitivity to minimum ionizing particles as compared to Xe-filled detectors. The experimental results are presented on the detector performance with X-rays of 6-60 keV and with relativistic electrons. They are accompanied by mathematical modeling and Monte Carlo simulations of transition radiation detectors based on this novel technique