Development of radiation hard planar silicon tracking detectors for the ATLAS Experiment at the HL-LHC

• Main Author: Forshaw, Dean
• Published: University of Liverpool 2014
• Subjects: 530; QC Physics
• Online Access: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.664329

To extend the physics reach of the LHC, upgrades to the accelerator are planned which will increase the integrated annual luminosity by a factor of 10 (to 250 - 300 fb$^{-1}$/ year). This will increase the occupancy and the radiation damage of the inner trackers. To cope with the elevated occupancy, the ATLAS experiment plans to introduce an all silicon inner tracker for use during High Luminosity LHC (HL-LHC) operation. With silicon, the occupancy can be adjusted by using the appropriate pitch for the pixels/micro-strips. Constraints due to high radiation damage mean that only sensors with electrode configuration designed to read out the electron signal (n-in-p and n-in-n) are considered. The work presented within this thesis has been undertaken as part of the CERN-RD50 and ATLAS Upgrade collaborations. The main focus has been, firstly, on the development of radiation hard silicon detectors and the possible exploitation of the charge multiplication effect observed in irradiated silicon detectors that collect charge via electrons. Secondly, the production and optimisation of n-in-p planar pixel detectors designed specifically for ATLASs new Inner Tracker (ITk). The prototype sensors were produced by Micron Semiconductors Ltd, UK.