Development of new high-precision timing detectors for the CMS experiment at HL-LHC
IDPASC Portugal - PHD Programme 2017
2017 / 2018
Experimental Particle Physics
Instituto Superior Técnico
Laboratório de Instrumentação e Física Experimental de Partículas
The subject of this thesis is the development of new high precision timing detectors for the CMS experiment in the high-luminosity phase of the LHC accelerator (HL-LHC). At the LHC, proton beams move in bunches around the LHC ring and collide every 25 nanoseconds. Each beam bunch contains approximately 10^11 protons and during their crossing time of 1ns an average of 30-50 proton collisions (pileup events) are taking place. In the High-Luminosity LHC (HL-LHC) an average of 140-200 pileup events will occur at each bunch crossing. In order to cope with this challenge, timing information provides a powerful discrimination to correlate particles from the same interaction and select the interesting events. Current detectors can achieve a time resolution of 0.5-1.0ns; this would be insufficient to maintain the sensitivity to rare physics processes in the HL-LHC era. A strong R&D program toward major upgrades of the CMS experiments is now starting and precise timing of charged particles is an important requirement of the program. The PhD student at LIP will take a major role in the development of a new Timing Detector based on LYSO scintillating crystals, silicon photomultipliers (SiPM) and dedicated ASIC electronics for the upgrade of the CMS experiment.