What will soon be the most powerful neutrino detector in the U.S. has recorded its first 3D images of particles. NOvA has begun collecting data from cosmic rays – particles produced by a constant rain of atomic nuclei falling on the Earth’s atmosphere from space.
“It’s taken years of hard work and close collaboration among universities, national laboratories and private companies to get to this point,” said Dr Pier Oddone, director of the Fermi National Accelerator Laboratory.
Scientists’ goal for the completed detector is to use it to discover properties of mysterious fundamental particles called neutrinos. Neutrinos are as abundant as cosmic rays in the atmosphere, but they have barely any mass and interact much more rarely with other matter.
“The more we know about neutrinos, the more we know about the early Universe and about how our world works at its most basic level,” explained NOvA co-spokesperson Dr Gary Feldman of Harvard University.
Later this year, Fermilab will start sending a beam of neutrinos 500 miles through the earth to the NOvA detector near the Canadian border. When a neutrino interacts in the NOvA detector, the particles it produces leave trails of light in their wake. The detector records these streams of light, enabling physicists to identify the original neutrino and measure the amount of energy it had.
“When cosmic rays pass through the NOvA detector, they leave straight tracks and deposit well-known amounts of energy. They are great for calibration,” said Fermilab researcher Dr Mat Muether. “Everybody loves cosmic rays for this reason. They are simple and abundant and a perfect tool for tuning up a new detector.”