With the CMS-Tracker the tracks of charged particles can be precisely reconstructed. Near the interaction point in the very center of the detector, these tracks are very dense. Furthermore, the LHC produces over 800 Million collisions per second requiring very fast and precise sensors. Only semiconductor sensors made from silicon have shown adequate performance and radiation hardness to operate in such an environment.

Similar to a digital photo camera which only takes a few two dimensional picture per second, the CMS-Tracker can record three dimensional pictures of charged particle tracks using 25 000 silicon strip sensors placed on several planes of concentric cylinders. The total surface is more than 200 m2 and the CMS Tracker his the largest scientific device using semiconductor sensors.

World's first silicon strip sensor on 8" wafer; © HEPHY
Silicon Sensor for the CMS Highly Granularity Calorimeter (HGCal); © HEPHY

Staff Members

CMS Tracker

Other members

CMS-Experiment; © CMS
CMS Tracker; © CERN
Higgs-Events; © CMS/CERN

The group is currently developing the next generation of radiation hard sensors for the new CMS Tracker. This second phase of the experiment will begin operation with the start-up of the High Luminosity LHC (HL-LHC) in approximately 2025. It will have to operate within a much more hostile radiation environment while being able to track ten times more particle than in the current experiment. The innovative but challenging concept of the new CMS Tracker will be described in detail in the upcoming Technical Design Report due for publication bu the end of 2017: The Phase-2 Upgrade of the CMS-Tracker

Since 2015, the group is also involved in the development of silicon sensors for the High Granularity Calorimeter (HGC). This detector will measure the energy of particles within the CMS experiment during operation with the HL-LHC. It uses a new concept for this type of detectors based on silicon sensor technology.

All of the above-mentioned developments are made in close cooperation with the  group for detector development. Together the groups carry the overall responsibility for the development and series production of the sensors for the Tracker and HGC collaborations. Furthermore, the group leader is part of the management team of the Tracker and jointly responsible for the operation of the existing detector and the construction of the new one.