The DarkSide-20k experiment will search for nuclear recoils resulting from collisions induced by dark matter particles with low-background detectors. The DarkSide-20k Ar-TPC, a double phase (gas-liquid) Argon Time Projection with an active mass of 23 t (20 t) for direct WIMP search, will be deployed within a shield/veto with a spherical Liquid Scintillator Veto inside a cylindrical Water Cherenkov Veto at the Gran Sasso Underground Laboratory in Italy. It The argon technology is unique in permitting operation of such large detectors in the “background-free” mode, thanks to the outstanding β/γ rejection power.

DarkSide-20k is designed to be the most powerful dark matter experiment searching for high mass dark matter to start data taking by 2020, accumulating a background-free exposure of 100 tonne×yr and to reach a sensitivity of 9×10-48 cm2 for a 1 TeV/c2 dark matter particle mass (9×10-47 cm2 for 10 TeV/c2).

The CIEMAT Dark Matter group is an active member of the collaboration since the proposal of the project. We are currently involved in:

  • Material selection and radioactive contamination measurements by Mass Spectroscopy (ICPMS) and HPGe analysis (in collaboration with the Canfranc underground laboratory, LSC).
  • LAr Time Projection chamber fabrication.
  • Calculation of the neutron spectra from 238U and 232Th material contamination and development of Monte Carlo simulations to assess the experiment background.
  • Data processing and sensitivity studies.