Characterization of irradiated and non-irradiated Low Gain Avalanche Detectors (LGADs)

Abstract

The objective of this work was to characterize the radiation hardness of the Fondazione Bruno Kessler (FBK) Ultra-Fast Silicon Detectors (UFSD) UFSD3.2 batch by comparing their capacitance-voltage characteristics before and after hadron irradiation at different fluence values. Stability tests gave an estimate of the radiation hardness against hadron radiation and the annealing studies showed the effect of beneficial annealing on the radiation damage. Transient current technique (TCT) was utilized to determine the operability of the sensors after the irradiation, and it was also used for determining the interpad distances. Some of the results were compared with previous measurements from Hamamatsu Photonics K.K. (HPK) sensor batch and with previous measurements from FBK UFSD3.1 batch, with the objective of getting an estimate of the performance compared to sensors from another manufacturer. All measurements and related activities were carried out at the Helsinki Institute of Physics (HIP) Detector Laboratory as a member of the Compact Muon Solenoid (CMS) upgrade research group.