DOE Pulse
  • Number 386  |
  • April 15, 2013

New particle detector records first 3-D tracks

A cosmic-ray muon deposits a large shower of energy in the NOvA detector in Minnesota.

A cosmic-ray muon deposits a large shower
of energy in the NOvA detector in Minnesota.

The NOvA particle detector, under construction in northern Minnesota, has begun recording its first three-dimensional images of particles. At its current size, the detector catches more than 1,000 cosmic rays per second. A webcam documents the progress of the construction of the humongous detector.

This summer, DOE’s Fermi National Accelerator Laboratory, located in Batavia, Ill., will start sending a beam of neutrinos every 1.3 seconds to the NOvA detector—500 miles straight through the Earth; no tunnel is necessary.

When complete in 2014, the full NOvA detector will be the most powerful neutrino detector in the United States. Made of PVC tubes that technicians will fill with scintillating liquid and outfit with light-sensitive electronics, the completed detector will weigh 14,000 tons. It will be the largest free-standing plastic structure in the world.

Scientists plan to use the NOvA experiment and Fermilab’s neutrino beam to discover the mass hierarchy of the three known types of neutrinos. Neutrinos are among the most abundant particles in the universe, but they have barely any mass and rarely interact with other matter particles. NOvA aims to discover which type of neutrino is the heaviest and which one is the lightest. The answer will shed light on the theoretical framework that scientists have proposed to describe neutrino interactions. Scientists suspect that neutrinos played a major role in the evolution of the universe. Neutrinos could help explain the imbalance of matter and antimatter in today’s universe, and scientists think there might be more types of neutrinos than the three known types.

“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,” said NOvA co-spokesperson Gary Feldman of Harvard University.

The NOvA detector will be operated by the University of Minnesota under a cooperative agreement with the DOE’s Office of Science. About 180 scientists, technicians and students from 20 universities and laboratories in the U.S and another 14 institutions around the world are members of the NOvA collaboration. The scientists are funded by the U.S. Department of Energy, the National Science Foundation and funding agencies in the Czech Republic, Greece, India, Russia, and the United Kingdom.

[Andre Salles, 630.840.3351,]