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We present an investigation of the interpad region (IP) in the Ultra-Fast Silicon Detector (UFSD) Type 10, utilizing a femtosecond laser and the transient current technique (TCT). We elucidate the isolation structure and measure the IP distance between pads, comparing it to the nominal value provided by the vendor. A comparison of sensors with identical layouts but different nominal IP distances (49 μm vs. 61 μm) and different processing parameters revealed their significant different charge collection properties in the IP. • fs-laser TCT can characterize the isolation structures of the segmented LGADs. • Charge multiplication is observed in the interpad region of the segmented LGADs. • The strongest interpad charge multiplication is observed close to p-stop implants. • Interpad length and doping are critical for charge multiplication between the pads. • Drop in interpad gap and increase of doping boost interpad charge multiplication. [ABSTRACT FROM AUTHOR]

The orange carotenoid protein (OCP) is a structurally and functionally modular photoactive protein involved in cyanobacterial photoprotection. Recently, based on bioinformatic analysis and phylogenetic relationships, new families of OCP have been described, OCP2 and OCPx. The first characterization of the OCP2 showed both faster photoconversion and back-conversion, and lower fluorescence quenching of phycobilisomes relative to the well-characterized OCP1. Moreover, OCP2 is not regulated by the fluorescence recovery protein (FRP). In this work, we present a comprehensive study combining ultrafast spectroscopy and structural analysis to compare the photoactivation mechanisms of OCP1 and OCP2 from Tolypothrix PCC 7601. We show that despite significant differences in their functional characteristics, the spectroscopic properties of OCP1 and OCP2 are comparable. This indicates that the OCP functionality is not directly related to the spectroscopic properties of the bound carotenoid. In addition, the structural analysis by X-ray footprinting reveals that, overall, OCP1 and OCP2 have grossly the same photoactivation mechanism. However, the OCP2 is less reactive to radiolytic labeling, suggesting that the protein is less flexible than OCP1. This observation could explain fast photoconversion of OCP2. Unlabelled Image • Excited-state dynamics of CAN is comparable in OCP1 and OCP2. • Photoactivation does not alter properties of ICT state of CAN. • CAN S* state identified exclusively in OCP2. • More constrained structure of CAN in OCP2 than in OCP1 • OCP2 is less flexible than OCP1. [ABSTRACT FROM AUTHOR]