CMS Hadronic Endcap Calorimeter Upgrade Studies for SLHC “P-Terphenyl Deposited Quartz Plate Calorimeter Prototype”

The Large Hadron Collider (LHC) is going to start taking data with 10³³ cm^-2s^-1 luminosity, and reach the designed value of 10³⁴ cm^-2s^-1 in 2013. The LHC luminosity will continue to improve each year, reaching to 10³⁵ cm^-2s^-1 in 2023. We call this high luminosity era the Super-LHC (SLHC). Hadronic Endcap (HE) calorimeters of the CMS experiment cover the pseudorapidity range of 1.4 ≪ η ≪ 3 on both sides of the CMS detector, contributing to superior jet and missing transverse energy resolutions. As the integrated luminosity of the LHC increases, the scintillator tiles used in the CMS Hadronic Endcap calorimeter will lose their efficiency. The CMS collaboration plans to substitute Quartz plates for the scintillator tiles of the original design. Various tests have proved Quartz to be radiation hard, but the light produced by Quartz comes from Cerenkov process, which yields drastically fewer photons than scintillation. To increase the light collection efficiency, we propose to treat the Quartz plates with radiation hard wavelength shifters, p-terphenyl or 4% gallium doped zinc oxide. The test beam studies revealed a substantial light collection increase on pTp or ZnO:Ga deposited Quartz plates. We constructed a 20 layer calorimeter prototype with pTp coated plates, and tested the hadronic and the electromagnetic capabilities at the CERN H2 area. Here we report the results of these test beams as well as radiation damage studies performed on p-Terphenyl.