The High Granularity Timing Detector (HGTD) is a new detector based on low gain avalanche detector technology proposed for the ATLAS Phase-II upgrade and covering the pseudorapidity region between 2.4 and 4.0. The typical number of hits per track in the detector was optimized so that the target average time resolution per track for a minimum-ionising particle is 30 ps at the start of lifetime, increasing to 50 ps at the end of HL-LHC operation. The high-precision timing information improves the pileup reduction to improve the forward object reconstruction, complementing the capabilities of the upgraded Inner Tracker (ITk) in the forward regions of ATLAS and leading to an improved performance for both jet and lepton reconstruction. These improvements in object reconstruction performance translate into sensitivity gains and enhance the reach of the ATLAS physics programme at the HL-LHC. In addition, the HGTD offers unique capabilities for the online and offline luminosity determination, an important requirement for precision physics measurements.


  • Physicists: Laurent Serin (staff), Dirk Zerwas (staff), Nikola Makovec (staff)
  • IT: Aurélien Blot, Julien Bonis, Aboud Falou, Alexandre Migayron
  • IT at Omega : Gisèle Martin-Chassard, Nathalie Segin-Moreau, Christophe de la Taille


  • A High-Granularity Timing Detector in ATLAS: Performance at the HL-LHC by Corentin Allaire (2019): Thesis
  • Research of Supersymmetry with the ATLAS detector and development of the High Granularity Timing Detector by Christina Agapopoulou (2020)


More information about the HGTD can be found in the Technical Proposal and the Technical Design Report


C. Allaire et al. « Beam test measurements of Low Gain Avalanche Detector single pads and arrays for the ATLAS High Granularity Timing Detector » JINST 13 (2018) 06, P06017 arxiv:1804.00622

C. Agapopoulou et al. « Performance of a Front End prototype ASIC for picosecond precision time measurements with LGAD sensors » JINST 15 (2020) 07, P07007 arxiv:2002.06089