The ICARUS detector being loaded into its cryostat at CERN. Photo: CERN

The ICARUS experiment studied neutrinos at Gran Sasso National Laboratory in Italy – operated by the Italian Institute for Nuclear Physics (INFN) – from 2010 to 2014, under the leadership of Nobel Laureate Carlo Rubbia. The ICARUS experiment pioneered the use of a new technology for spotting neutrinos using liquid argon. (It takes 760 tons of it fill the ICARUS detector). When neutrinos collide with argon atoms they create charged particles that can be tracked, and the detector produces beautiful 3-D images of those particles so scientists can study them. During its first run, the European particle physics laboratory CERN provided the beam of neutrinos that ICARUS studied.

In 2014 the detector was moved to CERN, where it has been refurbished and improved for its new mission. Now at U.S. Department of Energy’s Fermilab, the ICARUS detector will join two others (the in-progress Short Baseline Near Detector and the MicroBooNE detector, which has been recording neutrino tracks for more than a year and a half). Together, these three massive machines will search for a long-theorized but never-detected type of neutrino.

The newly built cryostat for the ICARUS detector, and the team that built it at CERN. Photo: CERN

Scientists have observed three types of neutrino – the muon, electron and tau neutrinos – and have also observed those neutrinos changing between types. Experiments such as the Liquid Scintillator Neutrino Detector (LSND) at Los Alamos National Laboratory and MicroBooNE’s predecessor at Fermilab, MiniBooNE, have seen hints that these three types might also be changing into a fourth type, one we have not been able to detect. The ICARUS detector and its two fellow neutrino hunters will use Fermilab’s neutrino beam to specifically seek evidence of this fourth type of neutrino.

ICARUS is the world’s first large liquid-argon neutrino detector, and the technology pioneered for that experiment will be the template for the Deep Underground Neutrino Experiment (DUNE), Fermilab’s new flagship. DUNE will use this technology to study the three previously observed types of neutrinos, and how they change between one type and another.

For more information, please visit the website for Fermilab’s short-baseline neutrino program.