The LHC accelerator and experiments will be operated well beyond 2035. For the CMS tracking detectors a two-phase upgrade is planned to ensure the best possible detector performance. Scientists from ETP contribute significantly to the replacement of the silicon pixel detector in the first phase and to the replacement of the entire tracking detector in the second phase (high luminosity phase, HL-LHC).
Phase 1: Silicon Pixel Detector
The silicon pixel detector of the CMS experiment has been replaced by a newly developed pixel detector in early 2017. The new detector allows more precise reconstruction of the trajectories of particles produced in the LHC collisions. Upgrades of the readout electronics enable clean separation of collision events at increased luminosities.
The new pixel detector has been built in a international collaboration. The list of German institutions includes KIT, RWTH Aachen, the University of Hamburg, and DESY. These institutions have shared production and testing of the new fourth detector layer in the central ("barrel") part of the detector. Between 2015 and 2016, ETP has produced about 400 modules for the new pixel detector, in close collaboration with the KIT Institute for Data Processing and Electronics. The new pixel detector has been commissioned in spring 2017 and is currently taking data.
Phase 2: Entire Tracking Detector
The end of lifetime for the CMS tracking detectors is expected after about 10 years of operation. According to current planning, the entire tracking detector will be replaced by a new more powerful detectors, which can be operated in the harsh environment expected at the HL-LHC. During the last year scientists from ETP have led a comprehensive campaign to evaluate the radiation hardness of modern silicon and diamond sensor materials.
The new tracking detectors will be designed to contribute to the online selection of collision events in addition to track reconstruction. With the novel concept of "pT modules" charged particle tracks with low transverse momenta pT can already be rejected online. Currently a series of pT module prototypes is being developed and intensely tested.