From a Fremilab press release, April 22, 2015:
The Italian ICARUS neutrino experiment – the world’s largest of its type – will move to Fermilab and become an integral part of the future of neutrino research in the United States (see Section 12.7c, p. 324-325).
Scientists will transport the liquid-argon neutrino detector across the Atlantic Ocean to its new home at the U.S. Department of Energy’s Fermi National Accelerator Laboratory. The 760-ton, 65-foot-long detector took data for the ICARUS experiment at the Italian Institute for Nuclear Physics’ (INFN) Gran Sasso National Laboratory in Italy from 2010 to 2014, using a beam of neutrinos sent through the Earth from CERN. The detector is now being refurbished at CERN, where it is the first beneficiary of a new test facility for neutrino detectors.
When it arrives at Fermilab, the detector will become part of an on-site suite of three experiments dedicated to studying neutrinos, ghostly particles that are all around us but have given up few of their secrets. All three detectors will be filled with liquid argon, which enables the use of state-of-the-art time projection technology, drawing charged particles created in neutrino interactions toward planes of fine wires that can capture a 3-D image of the tracks those particles leave. Each detector will contribute different yet complementary results to the hunt for a fourth type of neutrino.
Many theories in particle physics predict the existence of a so-called “sterile” neutrino, which would behave differently from the three known types and, if it exists, could provide a route to understanding the mysterious dark matter that makes up 25 percent of the Universe. Discovering this fourth type of neutrino would revolutionize physics, changing scientists’ picture of the Universe and how it works.