Gain layer degradation study after neutron and proton irradiations in Low Gain Avalanche Diodes

The high-luminosity upgrade of the ATLAS and CMS experiments includes dedicated sub-detectors to perform the time-stamping of minimum ionizing particles (MIPs). These detectors will be exposed up to fluences in the rangeof 1.5-2.5 × 10$^{15}$ n$_{eq}$/cm$^{2}$ at the end of their lifetime and, Low Gain Avalanche Diode (LGAD) has been chosen as their baseline detection technology. To better understand the performance of LGAD detectors in these environments, a gain layer degradation study after neutron and proton irradiations up to a fluence of 1.5 × 10$^{15}$ n$_{eq}$/cm$^{2}$ was performed. LGADs manufactured at Hamamatsu Photonics (HPK) and Centro Nacional de Microelectrónica (CNM-IMB) were chosen for this study and, a comparison in the gain layer degradation after exposure to reactor neutrons at the Jožef Stefan Institute (JSI) in Ljubjana and 24 GeV/c protons at the CERN-PS is presented here.