Silicon Sensors for Trackers at High-Luminosity Environment

TL;DR

This paper reviews recent advances in silicon sensor technologies developed by CERN's RD50 collaboration to meet the high radiation tolerance requirements of the HL-LHC upgrade, including new designs and materials.

Contribution

It presents recent experimental and simulation results on radiation-hard silicon sensors, highlighting innovations like thinned, 3D, active edge, and gain-enhanced sensors for high-luminosity collider environments.

Findings

Improved radiation tolerance in silicon sensors demonstrated

Novel sensor designs reduce charge trapping and increase sensitive area

Simulation results support experimental advancements

Abstract

The planned upgrade of the LHC accelerator at CERN, namely the high luminosity (HL) phase of the LHC (HL-LHC foreseen for 2023), will result in a more intense radiation environment than the present tracking system was designed for. The required upgrade of the all-silicon central trackers at the ALICE, ATLAS, CMS and LHCb experiments will include higher granularity and radiation hard sensors. The radiation hardness of the new sensors must be roughly an order of magnitude higher than the one of LHC detectors. To address this, a massive R&D program is underway within the CERN RD50 collaboration "Development of Radiation Hard Semiconductor Devices for Very High Luminosity Colliders" to develop silicon sensors with sufficient radiation tolerance. Research topics include the improvement of the intrinsic radiation tolerance of the sensor material and novel detector designs with benefits like reduced trapping probability (thinned and 3D sensors), maximized sensitive area (active edge sensors) and enhanced charge carrier generation (sensors with intrinsic gain). A review of the recent results from both measurements and TCAD simulations of several detector technologies and silicon materials at radiation levels expected for HL-LHC will be presented.