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Dr. Kent Leung, an Assistant Professor in �鶹��ý����’s Department of Physics and Astronomy, has received a Department of Energy research grant. Titled “Development of measurement cells for the neutron Electric Dipole Moment experiment at the Spallation Neutron Source,” the grant is a sub-award from the  and is expected to total $436,000 over five years. Leung joined �鶹��ý���� in September 2021 following research professor positions at NC State and Duke Universities.

The focus of the funded research is a measurement of the electric dipole moment of the neutron. While neutrons are (as their name implies) electrically neutral, they are composed of component particles called quarks, which are themselves charged. An electric dipole moment is a measure of how those charges are separated within the neutron. The neutron’s electric dipole moment is extremely small and has never been measured. Determining its value could shed light on fundamental problems in physics, such as how matter formed during the Big Bang or the existence of new particles that might explain dark matter.

“We are thrilled that Prof. Leung brings a new and exciting research field to our department—that of low-energy neutron physics”, says Marc Favata, chairperson of the Physics & Astronomy Department. “In addition to contributing to world-class research, this award will provide great hands-on experiences for our students—introducing them to state-of-the-art hardware and technology.”

Professor Leung is leading the development and construction of measurement cells—toaster-sized containers that will hold ultracold neutrons. These cells are cooled to 0.4 Kelvin (-459 F or less than half a degree above absolute zero); the neutrons they contain will have temperatures around 2 milli-Kelvins. The measurement cells will be installed in a building-size experiment at Oak Ridge National Laboratory in Tennessee. The goal of the experiment—which involves 22 universities and research laboratories—is a factor 100 improvement upon prior attempts to constrain the neutron’s electric dipole. To put the expected precision in scale, if the neutron were as large as the Earth, the experiment would be sensitive to charges separated by less than the width of a single virus particle.

We are like watch-makers poring over all the intricate parts of a complex experiment that we built—looking for tiny deviations in how our watch ticks.

Read and listen to the story about the project in an .