Buoyed by a $3 million federal grant, an experiment led by Yale University with partners from four U.S. Department of Energy (DOE) national laboratories and 10 universities including Le Moyne College will explore key questions about elusive particles called neutrinos — and potentially improve the way we monitor and safeguard nuclear reactors in the process
Watch this story about the research that ran on WSYR-TV.
The grant from the DOE Office of High Energy Physics will be used to build a first-of-its-kind, short-distance detection device for the Precision Oscillation and Spectrum Experiment (PROSPECT). The detection instrument will be constructed at Yale and later be deployed at Oak Ridge National Laboratory (ORNL), in Tennessee. The PROSPECT experiment has been in development for more than three years.
“It’s an excellent marriage of fundamental science and potential applications,” said Karsten Heeger, a Yale physicist and principal investigator for PROSPECT. “We want to better understand the emission of neutrinos from a reactor and study the fundamental properties of elementary particles.”
A great deal of scientific research is currently focused on neutrinos, which are subatomic particles that move through the universe with almost no mass and no electrical charge. Incredibly difficult to detect, neutrinos’ properties and behavior may hold answers to fundamental questions about the nature of matter in the universe.
One such property is oscillation — neutrinos’ ability to change among three known types, or “flavors.” The discovery of this process was recognized with the 2015 Nobel Prize in physics. Part of its significance comes from the glimpse it gives scientists into the possible existence of exotic forms of matter in the universe.
One way scientists are studying this oscillation is by detecting neutrinos created within nuclear reactors, such as the Daya Bay nuclear power plant in China. The Daya Bay experiment recently found that fewer neutrinos were being emitted than physicists had predicted. PROSPECT, by moving closer to a reactor core, will try to find out why.
“By going very close to a research reactor — less than 10 meters from the reactor core — PROSPECT will have unparalleled sensitivity to study the energy distribution of neutrinos as they leave the reactor,” Heeger said.
One explanation for the apparent neutrino deficit is the possible existence of a fourth type of neutrino known as a "sterile" neutrino. The interplay of the three known neutrino types and a sterile neutrino could result in a unique oscillatory pattern in the observed rate of neutrinos in the PROSPECT detector. Sterile neutrinos would represent a new form of matter.
Yet the apparent deficit might also be explained by shortcomings in theoretical models used to predict reactor neutrino abundances. For example, the fission cross-sections that lead to neutrino emission may not be that well known. A major goal of PROSPECT moving forward will be to probe these questions further.
“PROSPECT represents almost four years of dedicated research and development by our team of national laboratories and universities,” said Nathaniel Bowden, co-spokesperson for PROSPECT and a physicist at Lawrence Livermore National Laboratory. “Drawing on our extensive expertise in neutrino physics, liquid scintillator development, and reactor monitoring applications, PROSPECT has a mature, construction-ready system design that will result in a world-leading measurement.”
Brookhaven National Laboratory (BNL) chemists working with scientists at the National Institute of Standards and Technology (NIST) have been involved in developing the liquid scintillator – material that emits light in response to interactions with subatomic particles—that will fill the PROSPECT detector. This liquid contains an isotope of lithium that is readily able to absorb neutrons produced by the neutrino interaction. The excited lithium then produces a unique signature in the scintillator that allows scientists to tease out the signals produced by neutrinos from other subatomic particles entering the detector.
Le Moyne Assistant Professor Christopher Bass conducted preliminary research on liquid scintillator during his postdoctoral fellowship at the NIST Center for Neutron Research. “We were able to produce and characterize liquid scintillator containing enriched lithium and then demonstrate its neutron detection capabilities,” said Bass. “The liquid scintillator used in PROSPECT draws on this preliminary research and our collaboration’s extensive experience in scintillator development in neutrino experiments."
“These types of collaborations are indicative of the high caliber of the research programs at Le Moyne,” said Le Moyne President Linda LeMura. “Under Dr. Bass’s leadership, our students will have opportunities to be part of an initiative that is truly groundbreaking. We are absolutely thrilled to be part of the PROSPECT experiment.” Dr. LeMura noted that Le Moyne is the only institution collaborating on the experiment that is not a national laboratory or Research 1 university (as classified by Carnegie Classification of Institutions of Higher Education).
Institutions collaborating on PROSPECT include: Brookhaven National Laboratory, Drexel University, Georgia Institute of Technology, Illinois Institute of Technology, Lawrence Livermore National Laboratory, Le Moyne College, National Institute of Standards and Technology, Oak Ridge National Laboratory, the University of Tennessee-Knoxville, Temple University, the University of Waterloo, the College of William and Mary, the University of Wisconsin-Madison, and Yale University.
For more information about PROSPECT, click here.