Study of GSO scintillator for upgrade of LHCf detectors

摘要

Gd2SiO5 (GSO) scintillator has very excellent radiation resistance with fast decay time and large amount oflight yield. The radiation hardness of GSO was examined by using Carbon ion beams at Heavy Ion Medical Acceleratorin Chiba (HIMAC). Through two nights of irradiation a GSO scintillator was received 7 × 105Gy of total dose and no decrease of light yield was observed. On the other hand an increase of light yield by 25% was observed. The increaseis marginally proportional to the total dose at the rate of 0.025%/Gy and it is saturated at 1 kGy. Recovery to the initiallight yield was also observed during the day between two nights. The time scale of recovery is about 15,000 seconds. Incase of the LHCf experiment, very forward region (pseudo-rapidity > 8.4) experiment at the LHC, the irradiation rateis expected to about 100Gy for 10nb-1 of data taking at ps = 14TeV proton-proton collisions. Expected increase ofless than a few % will not be a big problem for the LHCf experiment.