Faculty of Engineering and Natural Sciences
Short and Long Term Upgrade Scenarios for the CMS Hadronic Calorimeter
World is waiting for the data that will open the doors of new physics, and the four LHC experiments are getting ready for 14 TeV collisions. This unprecedented quest for discovery requires constant upgrade studies on the detectors of each experiment. The Compact Muon Solenoid (CMS) is a general-purpose detector designed to run at the highest luminosity provided by the LHC. The CMS Hadronic Endcap (HE) and Hadronic Forward (HF) calorimeters cover the pseudorapidity range of from 1.4 to 5 on both sides of the CMS detector, contributing to superior jet and missing transverse energy resolutions, which will be the key for physics discovery. However these hadronic calorimeters are far from being perfect. Here we discuss possible upgrade scenarios for both calorimeters.
Recent studies revealed abnormally high amplitude signals due to punch through charged particles, mostly muons, producing Cherenkov photons at the HF calorimeter PMT window. Our studies show that these events can be eliminated either by using the timing properties, or replacing the HF PMTs with new generation four anode PMTs.
We also need to address the radiation damage problems of HE calorimeters as the LHC increases peak luminosity to 1035cm-2s-1 in near future. As the integrated luminosity of the LHC increases, the scintillator tiles used in the CMS Hadronic Endcap calorimeter will lose their efficiency. Here we outline two possible radiation hard upgrade scenarios based on substituting quartz plates for the scintillator tiles of the original design.
January 6th, 2010, 13:40,