Background Estimation on ME0 Region Using FLUKA

The CMS muon system plays an important role in the discovery of new physics like the Higgs boson and new particles. The next phase of the LHC is planned to increase luminosity to improve the discovery power. The high luminosity LHC (HL-LHC) will be a harsh environment of pp collisions and will require high-performance muon trigger and muon track reconstruction, especially in the endcap region of the CMS muon system. In order to maintain its performance, the CMS collaboration has decided to add three detector systems with a Gas Electron Multiplier (GEM) technology in the endcap regions. One of them is six layers of triple-GEM chambers at Station 0 (ME0), located at z $\approx$ 5.5 m between HGCAL and Station-1 muon system (ME1/1 and GE1/1). The ME0 system covers 2.03 $< \lvert\eta\rvert <$ 2.82, where large fluxes for neutrons, photons, electrons & positrons and charged hadrons are expected. In the present study, fluences at the ME0 station with 11 different radiation shielding designs are examined using FLUKA simulation, reporting an optimized design of radiation shielding.