Study on background full simulation and implementation for Super Tau-Charm Facility

Abstract The Super Tau-Charm Facility is a new generation high luminosity electron-positron collider designed to operate in the tau-charm energy region. With the designed peak luminosity of at least 0.5 × 10 35 cm -2 s -1 , the background full simulation and implementation would be an important part in the detector study. Based on Offline Software of Super Tau-Charm Facility, the software platform for STCF, the spectrometer structure modeling, simulation for both luminosity-related and beam-related background sources, the random mixing algorithm of signal and background are carried out. The simulation result indicates that the highest TID in STCF detector is 4700 Gy/y, the highest NIEL damage is below 10 11 1 MeV neutron·cm -2 y -1 except MDC, and the highest SEEs is below 2 kHz/cm 2 . The cross check with FLUKA also indicates a similar magnitude for both the TID and NIEL damage simulation result, except MDC NIEL damage due to the (n, p) reaction was not considered in FLUKA. The highest background total count rate is hundreds of MHz for most of detectors, the highest count rate per channel is approximately 720 kHz/channel in ITKW and 580 kHz/channel in ECAL. This work presents a systematic background evaluation route based on GEANT4, which is easy to combine with the further detector performance study. These simulation results indicate that all the systems can tolerate the background with the newly developed detector and electronics technologies. Moreover, the further optimization of STCF lattice design, the shield in MDI and detector systems are still required to suppress the background to an even lower level for a better detector performance. Meanwhile, the physics signal can be well mixed with the randomly sampled background data at the level of GEANT4 steps, aiming to simulate the realistic situation of the detector and providing necessary database for detector performance optimization and physics study.