The ATLAS ITk (Inner Tracker) will be a full silicon tracker, with pixels for the 5 first layers and strips for the outer layers. The pixel detector itself comprises 3 sub-systems : the Inner System (IS) includes the two layers closest to the beam pipe, and the Outer Barrel (OB) and Outer EndCap (OEC) for the remainig three layers.

ITkLayout red

It is meant to be installed in ATLAS during the third long shutdown of the LHC (LS3) and to take data at the HL-LHC.

HL LHC Janvier2022 The past and current contributions of the LPSC concern

  • prototyping of staves
  • R&D on Silicon Power Resistors for thermal testing
  • thermal and mechanical testing of the staves     
  • R&D on gluing the modules on the cells
  • R&D on CO2 cooling
  • development of the OB intermediate supports
  • definition of the OB type-1 cables
  • material simulation
  • ...



Like the other french laboratories, LPSC is mainly involved in the Outer Barrel. Part of the modules are 'flat', i.e. parallel to the beam line, supported by longerons, while the rest of the modules are inclided with ring-shaped mechanical supports.


The LPSC project is a loading site for the pixel Outer Barrel. "Loading" means equipping the longerons and rings with the modules. To this effect, a clean room was built, in which a CMM was installed in 2018. The R&D for the loading is being finalized, and the LPSC should be qualified around the end of 2022 or begining of 2023.

DSC00383 electTestsSetup


The Team

The physicists involved are Fabienne Ledroit (coordinator), Johann Collot (CO2 cooling coordinator), Jean-Baptiste de Vivie (team leader) and Marie-Hélène Genest.

The technical coordinator is Patrick Stassi. The services contributing are the SDI (Detectors and Instrumentation), SERM (mechanics) and Service d'Electronique (electronics).




Additional material 

Link to mechanics activities (french only)