The DarkSide-20k TPC and underground argon cryogenic system

Abstract

DarkSide-20k (DS-20k) will exploit the physical and chemical properties of liquid argon (LAr) housed within a large dual-phase time project chamber (TPC) in its direct search for dark matter. The TPC will utilize a compact, integrated design with many novel features to enable the 20t fiducial volume of underground argon. Underground Argon (UAr) is sourced from underground CO_22 wells and depleted in the radioactive isotope ^{39}39Ar, greatly enhancing the experimental sensitivity to dark matter interactions. Sourcing and transporting the \mathcal{O}𝒪(100t) of UAr for (DS-20k) is costly, and a dedicated single-closed-loop cryogenic system has been designed, constructed, and tested to handle the valuable UAr. We present an overview of the (DS-20k) TPC design and the first results from the UAr cryogenic system.