DarkSide-20k is a direct dark matter search experiment of the multinational Global Argon Dark Matter Collaboration (GADMC), which will be constructed at the LNGS underground laboratory in Italy. With extremely low background levels, sensitivity to WIMP-nucleon cross section of 1.5x10^47 cm^2 at WIMP mass of 1 TeV/c^2 will be achieved with exposure of 100 t yr, beyond ongoing and currently planned experiments.
The core of the experiment is a dual-phase TPC filled with 50t of low-radioactivity argon sourced from a deep underground source, deployed in a membrane cryostat with ~700t of atmospheric liquid argon. The latter provides passive radiation shielding, while the neutrons are actively vetoed via gadolinium-loaded acrylic. Both the TPC and neutron veto are instrumented with cryogenic silicon photomultipliers.
For argon extraction and purification, a unique dedicated facility Urania is under development, which will be capable to extract more than 300kg/d of low-background argon gas. Its chemical purification and isotope separation will be performed at the Aria plant, a 350 m cryogenic distillation column under construction, with a successfully operated prototype.
A simplified version of a compact TPC argon cryogenic and gas circulation system is nearly complete and being prepared for commissioning and tests. TPC prototypes of various scales have been run and are in preparation.
In this seminar, technical aspects and the status of the experiment will be covered, including pioneering R&D on photosensors and associated electronics, wavelength-shifters and conductive polymers, underground gas extraction, purification, and cryogenics.
Alessandro Marchioro (EP-ESE) and Burkhard Schmidt (EP-DT)