News Brief
August 03, 2017 
OAK RIDGE, Tenn - A team of physicists, including 3 from the D.O.E.'s Pacific Northwest National Lab, has found a big fingerprint of one of the smallest particles - the neutrino - that interacts only weakly with matter. The work will ultimately help scientists understand the universe better.
The research, performed at the DOE's Oak Ridge National Lab's Spallation Neutron Source and reported in the journal Science, provides compelling evidence for a neutrino interaction process predicted by Standard Model theorists 43 years ago, but never seen.
The scientists, a collaboration of 80 researchers from 19 institutions and four nations performing the COHERENT experiment, are the 1st to detect and characterize a phenomenon known as coherent elastic scattering of neutrinos off nuclei. In this behavior, a neutrino bumps into the entire the nucleus of an atom and imparts a tiny amount of energy to the nucleus.
The energy's signal is as tough to spot as a bowling ball's recoil after a ping-pong ball hits it. In nature, the phenomenon occurs during neutron star formation and supernovae explosions.
The team took advantage of the fact that the SNS generates a high amount of neutrinos as a byproduct of its normal operations in research. Placing the world's smallest neutrino detector a mere 65 feet (20 meters) from the neutrino source at SNS vastly improved the chances of detecting interactions.
Physicist Juan Collar of the University of Chicago led the design of the detector used at SNS. 3 physicists from PNNL - John Orrell, Todd Hossbach and Cory Overman - helped build the detector. Among other contributions, the instrument relied especially on copper free from background radiation coming from cosmic rays pouring in from the universe. The PNNL researchers electroformed the ultrapure copper in PNNL's underground Lab, where cosmic rays can't reach.
Read more about neutrinos, the detector and the COHERENT team in ORNL's news release.
Tags: Energy, Fundamental Science, Physics, Materials
Interdisciplinary teams at Pacific Northwest National Lab address many of America's most pressing issues in energy, the environment and national security through advances in basic and applied science. Founded in 1965, PNNL employs 4,400 staff and has an yearly budget of nearly $1 billion. It is managed by Battelle for the D.O.E.'s Office of Science. As the single biggest supporter of basic research in the physical sciences in the United States, the Office of Science is working to address some of the most pressing challenges of our time. For more information on PNNL, visit the PNNL News Center, or follow PNNL on Facebook, Google+, Instagram, LinkedIn and Twitter.
