Precision timing photon detectors using Cadmium-Telluride sensors

Precision timing properties of high energy physics detectors in high luminosity colliders has become an important requirement for the success of particle detection, of which new calorimeter with timing precision of few tens of ps is the main interest. In this paper, we presented the first calorimetry and timing performance measurement of Cadmium-Telluride (CdTe) as the active material of sampling calorimeter, using 2 GeV to 200 GeV electron beam from CERN beam lines. A good energy performance is achieved due to the better sensitivity of CdTe to X ray photons in the secondary shower than other semi-conducting sensors such as silicon. The timing resolution of the tested CdTe sensor is measured to be down to 21 ps under the best conditions.