Low Gain Avalanche Detectors for 4-dimensional Tracking Applications in Severe Radiation Environments

Abstract

For the High Luminosity upgrade of the CERN Large Hadron Collider (HL-LHC), the collider will reach a peak instantaneous luminosity of 5 × 1034 cm−2 s−1, with a total integrated luminosity of ∼3000 fb−1 after around 12 years of expected lifetime. The pile-up during the p+p+ collisions is expected to reach values of ∼200 and the experiments are expected to be exposed to radiation levels up to 1.6 × 1016 neq cm−2 at the innermost layers of the detectors. Moreover, in future proposal colliders, like for example FCC-hh, the pile-up is expected to be a factor of five higher while the radiation levels will increase by a factor of ten with respect to the HL-LHC. Under this scenario, in the framework of ATLAS, CMS, RD50 and other sensor R&D projects, radiation tolerant silicon sensors for timing and tracking applications are being developed. Giving the expected radiation levels and the demanding spatial resolution plus timing capabilities required, one important line of research is focused on silicon sensors with intrinsic charge gain: Low Gain Avalanche Detectors (LGADs). This paper aims to give an overview of the current status of this technology. The most interesting approaches for future 4-dimensional tracking applications based on the LGAD technology will be presented here. In addition, the latest results on the performance after irradiation of standard LGADs will be reviewed too.