CMS Hadron Endcap Calorimeter Upgrade Studies for Super-LHC

When the Large Hadron Collider approaches Super-LHC conditions above a luminosity of $10^{34} cm^{-2} s^{-1}$, the scintillator tiles of the CMS Hadron Endcap calorimeters will lose their efficiencies. As a radiation hard solution, the scintillator tiles are planned to be replaced by quartz plates. In order to improve the efficiency of the photodetection, various methods were investigated including radiation hard wavelength shifters, p-terphenyl or 4\% gallium doped zinc oxide. We constructed a 20 layer calorimeter prototype with pTp coated plates of size 20 cm x 20 cm, and tested the hadronic and the electromagnetic capabilities at the CERN H2 beam-line. The beam tests revealed a substantial light collection increase with pTp or ZnO:Ga deposited quartz plates. Here we report on the current R\&D for a viable endcap calorimeter solution for CMS with beam tests and radiation damage studies.