New SDD arrays for the SIDDHARTA-2 experiment

This paper reports on the development of novel 2×4 monolithic Silicon Drift Detector (SDD) arrays with a thickness of 1 mm, carried out in the context of the SIDDHARTA-2 experiment, representing an advancement in terms of detection efficiency over the presently adopted 450 μm thick detectors. The chip contains eight square SDD cells with an active area of 8 × 8 mm2 each and has a total dimension of 20 mm × 36 mm. Besides an optimization of the sensor design for the thicker substrate, this new version of the SDD array is characterized by the introduction of an additional electrode on the entrance window, which should reduce the charge sharing between pixels. The paper also describes the development of a detection module based on a stacked structure involving two SDDs placed atop each other. This solution aims to further increase the detection efficiency of the system without acting on the substrate thickness of the SDD. The results from the spectroscopic characterization of these new detectors, and the implementation and characterization of the stacked SDDs module will be presented at the conference.