Speaker
Description
Aiming to a sub 30 psec time resolution at fluences in excess of $6×10^{15}$ 1 MeV $n_{eq}/cm^{2}$, several dopants are explored to improve radiation tolerance of intrinsic gain sensors. Using a common mask, CNM produced LGADs with boron, boron + carbon and gallium implanted gain layers are subjected to neutron and proton irradiation ranging from $10^{14}$ to $6×10^{15}$ 1 MeV $n_{eq}/cm^{2}$ on both particle species. A systematic study of acceptor removal, gain reduction and timing performance is presented at different temperatures ($-10^{o}C$, $-20^{o}C$, $-30^{o}C$). Charge collection, relative efficiency, signal shape and noise analysis are also addressed, using charged particles in a laboratory setup. Three different approaches are used to individually evaluate different mechanisms of radiation damage and their effect on sensor performance, with a distinction between bulk and gain layer effects. Finally, stability is evaluated via dark count rate, which combined with efficiency, determines the sensor's operatable region and it's evolution with radiation.
