Reduced-Channels Position-Sensitive 10×1 SiPM Tile for Scintillator-Bars Readout

Silicon photomultipliers (SiPMs) are solid-state single-photon-sensitive detectors more and more used in a large variety of applications, like in high-energy physics (HEP) and space experiments. Recently, one of the main requirements is to cover larger active areas, possibly with a reduced number of channels. In such a scenario, position-sensitive SiPMs have been developed, in which the interaction position is provided by the amplitudes (or charge) of a few output signals. This is commonly done at the single-chip level. Inspired by this concept, in this contribution, we developed a tile of $10\times 1$ SiPMs ( $\sim 3\times 3$ mm2 each) with two output channels, properly spaced to read out an array of ten scintillator bars, covering a total length of 51 mm. Despite being developed to be used in a particle-detection telescope, the concept is general. In the $10\times 1$ tile, each SiPM is connected to two amplifiers (integrated on the backside of the board) through a couple of position-weighted resistors (conductance gradually varying between the first channel and the last channel). With such an approach, it is possible to recover the total energy deposited through the sum of the two signal amplitudes, while their normalized difference determines the triggered SiPM, i.e., the coordinate of the scintillating bar within the array. We detail the design, the dimensioning of the $10\times 1$ tile, the preliminary characterization with pulsed light, and the final measurements when coupled to the scintillator bar array detecting electrons or alpha particles.