Radiation Damage in 20-cm Long LYSO:Ce and BaF2:Y Crystals

Inorganic scintillators are widely used in highenergy physics (HEP) experiments. Bright and fast cerium-doped lutetium yttrium oxyorthosilicate (Lu2(1-x) Y2xSiO5:Ce or LYSO:Ce or LYSO) crystals are being used to construct the compact muon solenoid (CMS) barrel timing layer (BTL) detector at the high-luminosity large hadron collider (HL-LHC), where up to 2.5-Mrad ionization dose, 1.7 x 10(13) charged hadrons/cm(2), and 2 x 10(14) n(eq)/cm(2) are expected. With an ultrafast scintillation of less than 0.6-ns decay time and a suppressed slow component, yttrium-doped barium fluoride (BaF2:Y) crystal is a promising ultrafast inorganic scintillator for future HEP time of flight and calorimeter applications at the energy and intensity frontiers. The 20-cm-long LYSO:Ce and BaF2:Y crystals were irradiated by 800-MeV proton beam at the blue room of Los Alamos Neutron Science Center (LANSCE) up to 7.5 x 1015 p/cm(2). We report on the degradation of their optical and scintillation properties.