A High-Granularity Timing Detector for the ATLAS Phase-II upgrade

Abstract

The High Luminosity Large Hadron Collider (HL-LHC) will reach an integrated luminosity up to 4 000 fb-1 from 2029 to 2039. The number of collisions per bunch crossing will significantly increase, rising a challenge in terms of pileup mitigation that will have a severe impact on the ATLAS detector performance. Therefore, the HighGranularity Timing Dectector (HGTD) will be installed in front of the Liquid Argon Calorimeter (LAr) covering the forward region with a pseudo-rapity from 2.4 to 4.0. HGTD will provide a time measurement of the time for Minimum Ionizing Particles (MIP) with a 30 ps per track resolution and will be coupled to the futur tracking detector (ITk) to assign each particle to a vertex. HGTD will be composed of 3.6 million readout channels, including a Low Gain Avalanche Diode (LGAD) based technology sensors and a front-end readout chip (ASIC) based on the 130 nm CMOS technology. These latest will be combined and assembled to produce a module, that will be installed and glued on a support unit. This article presents a general overview of the HGTD project, its status and some highlights of sensitive components.