Performance of the combined zero degree calorimeter for CMS

Understand

The combined zero degree calorimeter (ZDC) is a combination of sampling quartz/tungsten electromagnetic and hadronic calorimeters.

• Two identical combined calorimeters are located in the LHC tunnel at CERN at the straight section ~140 m on each side of the CMS interaction vertex and between the two beam pipes.
• They will detect very forward photons and neutrons.
• ZDC information can be used for a variety of physics measurements as well as improving the collision centrality determination in heavy-ion collisions.