Research & Development

The Recoil Directionality (ReD) project has operated a miniaturized dual-phase Argon TPC, readout by Silicon Photomultipliers (SiPM) since 2018. ReD’s goal is to study the response of argon to nuclear recoils, including:

• • • scrutinizing sensitivity to the direction of the nuclear recoil, motivated by the results of the previous SCENE experiment;
    • measuring the response of the detector to very low-energy nuclear recoils (< few keV), as would be produced by low-mass dark matter candidates.

As the ReD TPC features the DarkSide-20k SiPM technology, it is a very valuable test bench for studying the performance of these sensors under a range of operating conditions.

Silicon Photomultipliers (SiPMs) are highly sensitive light detectors composed of thousands of tiny photon-counting pixels called Single Photon Avalanche Diodes (SPADs). They can detect individual photons and produce signals proportional to the number of photons detected, making them ideal for the extremely low-light conditions of dark matter experiments. While thermal noise can generate false signals at room temperature, operating SiPMs in liquid argon greatly suppresses this effect. For DarkSide-20k, custom SiPMs developed by Fondazione Bruno Kessler and manufactured by LFoundry provide high photon detection efficiency, low noise, and large-area coverage, enabling precise measurement of the faint light signals produced by rare particle interactions.