Laser-based performance comparison of LGAD sensors for precision timing detectors at hadron colliders

Abstract We present a comparative characterization of three 50-μm low-gain avalanche diode (LGAD) sensors fabricated by different foundries and production batches. Static electrical properties and dynamic charge and timing responses were evaluated within a common experimental framework using a calibrated 1065 nm transient-current-technique (TCT) system. Breakdown voltages were determined with a consistent k-factor criterion, while gain and timing performance were assessed using PIN-diode normalization and a common pulse-fitting procedure. Among the three devices, K2 provides the most favorable combination of the widest usable bias margin and the smallest measured effective timing resolution, 24.23 ps at the 15 fC normalized-charge reference point. These results provide practical guidance for the operating-point assessment of LGAD sensors for precision timing detectors at the HL-LHC.