Speaker
Description
Weakly Interacting Massive Particles (WIMPs) are among the most compelling candidates for particle dark matter, and their direct detection remains one of the central goals of astroparticle physics. Dual-phase liquid argon time projection chambers have emerged as one of the leading technologies for probing light galactic dark matter, particularly for masses below $10~\mathrm{GeV}/c^{2}$, as demonstrated by the DarkSide-50 experiment using 50~kg of underground liquid argon. Motivated by the excellent background rejection and sensitivity achieved by DS-50, scaling this technology to multi-tonne target masses is essential to reach background-free operation and extend direct detection searches toward the neutrino floor.
DarkSide-20k is a next-generation cryogenic dark matter experiment hosted at the Laboratori Nazionali del Gran Sasso, designed to achieve instrumental background-free sensitivity in the search for WIMP interactions. The experiment employs a 50-tonne dual-phase liquid argon time projection chamber as its inner detector, using underground argon as the active target to suppress intrinsic radioactive backgrounds. The inner detector is based on an ultra-pure octagonal PMMA vessel, with a field cage implemented using a commercial conductive polymer coating (Clevios) with better than $100~\mu$m uniformity, and inner surfaces lined with TPB-coated enhanced specular reflector foils to efficiently shift argon scintillation light to 420~nm for optical detection. Dual top/bottom planes house $\sim$200k cryogenic FBK NUV-HD SiPMs organized in 528 photodetector modules (PDMs) with $>40\%$ photon detection efficiency.
This presentation focuses on the design of the DarkSide-20k inner detector, with particular emphasis on the mechanical implementation of the PMMA vessel, field cage integration, and optical system layout. The architecture of the silicon photomultiplier--based photon detection system will be discussed, including the organization of SiPM arrays into photodetector modules and their role in achieving high photon detection efficiency and improved pulse-shape discrimination. Key design considerations relevant to radiopurity, and detector performance will be highlighted.
| Keyword-1 | Liquid Argon Time Projection C |
|---|---|
| Keyword-2 | Low-Background Techniques |