Figure 4

Normalized timing response histogram for representative APDs from group 4 using a pulsed laser, before and after irradiation, measured at \(\pmb{-60^{\circ}\mbox{C}}\). The full width half maximum (FWHM) timing jitter before irradiation was ≈600 ps for SLiK, ≈550 ps for C30921SH, and ≈700 ps for SAP500S2. Changes in the baseline count probabilities are due to the changes in DCRs. At FWHM there is no noticeable change in the timing response of SLiKs and SAP500S2 before and after irradiation, and a moderate increase of 100 ps was observed for C30921SH. Measured timing jitter includes timing jitter of the laser and time tagger.