Speaker
Description
Future lepton colliders, such as FCC-ee, impose stringent requirements on jet energy resolution, targeting approximately 3% to 4% at 90 GeV. Within the IDEA detector concept, dual-readout calorimetry has been adopted as a baseline approach, exploiting the simultaneous measurement of scintillation and Cherenkov light to correct hadronic shower response fluctuations on an event-by-event basis. The HiDRa (Highly Granular Dual-Readout Calorimeter) demonstrator is a fiber-sampling calorimeter based on 1 mm diameter scintillating and clear fibers embedded in 2 mm stainless-steel capillaries, each read out by a Silicon Photomultiplier (SiPM). While the demonstrator validates the feasibility of a modular and 4π-compatible geometry, the scaling to the almost 50 millions of channels required for a full detector poses demanding constraints in sensor equalization, stability, and large-scale calibration.
The ASPIDES collaboration is developing a monolithic SPAD array with integrated front-end electronics in a 110 nm CMOS image sensor technology for particle-physics applications, including dual-readout calorimetry, RICH detectors and high-pressure TPCs. One of the prototypes recently submitted for fabrication is targeting the requirements of dual-readout calorimetry. It consists of 1024 micro-cells with a 30 µm pitch and 50% fill-factor, covering an overall area of about 1 mm². The readout architecture provides on-chip photon counting, sub-100 ps time-stamping capability, and dedicated noise mitigation strategies.
This contribution reports on the submitted architecture and the characterization of a previous prototype implemented in the same technological node, performed to validate the CMOS SPAD technology. The chip integrates multiple array configurations with different SPAD active areas, quenching architectures, and readout schemes, allowing a systematic comparison of parameters. Special emphasis is given to the measurements of spurious effects, including dark count rate (DCR), optical crosstalk and afterpulsing.