The Fast Beam Conditions Monitor (FBCM) is the only independent luminosity detector of CMS during the HL-LHC era, designed for rapid monitoring of beam conditions an‎d the measurement of luminosity an‎d beam- induced background (BIB). At the FBCM installation location, the maximum expected radiation fluence is approximately 2.5 × 1015 1MeVneq/cm2 ; therefore, the components used must be highly radiation tolerant. Two can‎didate silicon sensor types have been considered, an‎d their performance under such conditions needs to be eva‎luated. The goal of this thesis is to aid in selec‎ting the optimal sensor by studying an‎d comparing their electrical characteristics before an‎d after irradiation. Radiation leads to increased leakage current an‎d deple- tion voltage, reduced collected signals, an‎d decreased detector performance an‎d resolution. In this study, the electrical properties of the sensors are first investigated using Silvaco TCAD, an‎d then, using Allpix 2 —an open-source Monte Carlo-based simulator—the induced current an‎d signal response of the sensors are ana- lyzed. Finally, the simulation results are compared with laboratory measurements, an‎d the observed behavior is interpreted using simulation models. These results provide a detailed insight into the sensors’ performance under various radiation conditions an‎d can guide the selec‎tion of sensor type an‎d optimization of the FBCM detector design.

حامد بخشيان , محمد صدقي

عبيده جعفري

مريم حسنوند , حسين احمدوند