Searching for light Dark Matter with Spherical Proportional Counters

by Konstantinos Nikolopoulos (DESY HH)

Thursday 20 Apr 2023, 10:00 → 12:00 Europe/Berlin

Nußallee 12/1.049 (PI) - Conference Room II (PI)

The NEWS-G collaboration is searching for light dark matter using spherical proportional counters. Access to 50 MeV to 10 GeV mass range is enabled by the combination of single electron threshold, light gaseous targets (H, He, Ne), and highly radio-pure detector construction. Initial NEWS-G results obtained with SEDINE, a 60 cm in diameter spherical proportional counter operating at the Laboratoire Souterrain de Modane (France), excluded for the first time WIMP-like dark matter down to masses of 0.5 GeV. The latest advances in instrumentation and the construction of a new, 140 cm in diameter, spherical proportional counter constructed using 4N copper with a 500 um underground electroplated copper inner layer will be presented. The detector is installed at SNOLAB (Canada), where it is being commissioned and is scheduled start data collection imminently. Future prospects and applications of spherical proportional counters will be discussed, and the potential to achieve sensitivity reaching the neutrino floor in low mass dark matter searches with a next-generation detector will also be summarised.