SoLAr detector prototyping

The SoLAr concept introduces a novel liquid-argon neutrino detector technology to enhance sensitivity in the MeV energy range, broadening the scope to include solar and supernovae neutrinos. This technology is based on a monolithic light-charge pixel-based readout, offering a low energy threshold, exceptional energy resolution (approximately 7%), and effective background rejection through pulse-shape discrimination. The primary objective is to observe solar neutrinos in a 10-kiloton-scale detector, ultimately leading to precise measurements of the 8B flux, improved solar neutrino mixing parameters, and the first observation of the hep neutrino flux. It is also a timely technology choice for the DUNE “Module of Opportunity”, which could serve as a next-generation multi-purpose observatory for neutrinos from the MeV to the GeV range. A staged prototyping program is in progress to validate the viability of this detector concept, with a prospect to build a medium-sized demonstrator in the Boulby Underground Laboratory. Here, we present preliminary results from the prototype run in July 2023, showcasing cosmic muon tracks detected for the first time with an integrated light and charge readout.