Beam-test of CMOS pixel sensors with 6 GeV electrons

Abstract CMOS monolithic pixel sensors have emerged in recent years as a viable option for particle tracking applications at high-energy physics experiments. Their capability of integrating the sensing element, the first readout and the processing electronics on the same substrate allows the fabrication of highly segmented sensors which provide an excellent spatial resolution with a minimum material budget. In this study, a reticle-size prototype, featuring more than 1 million pixels distributed over an area of 3.5 cm 2 , has been tested in a series of beam-tests with the 6 GeV electron beam of the DESY-II synchrotron in DESY (Hamburg, Germany). The detector tracking capabilities have been studied with the aid of a silicon reference telescope. Results are presented concerning the sensor charge collection properties, detection efficiency and spatial resolution as a function of the operational temperature and of the electron beam energy.