University of Chicago scientists are learning how to collect and comprehend the small, elusive particles known as neutrinos thanks to a nuclear reactor at an Illinois energy facility.
The scientists used a small detector to take the first observations of neutrinos coming from a nuclear reactor at Constellation’s (previously Exelon) Dresden Generating Station near Morris, Illinois. These particles are incredibly difficult to detect because they interact with matter so seldom, yet power reactors are one of the few sites on Earth where they are abundant.
Prof. Juan Collar, a particle physicist who conducted the study, stated, “This was an exciting chance to profit from the tremendous neutrino production from a reactor, but it was also a difficulty given the loud industrial environment directly next to a reactor.” “Neutrino physicists have come the closest to replicating a commercial reactor core. Thanks to Constellation’s willingness to accommodate our experiment, we obtained unique expertise operating a detector under these circumstances.”
With this information, the team plans to conduct further measurements in the hopes of finding answers to puzzles concerning the underlying rules that govern particle and nuclear interactions.
Because neutrinos can inform scientists what’s going on in the core of the reactor, the technology might be beneficial in nuclear nonproliferation. As a precaution, detectors might be put near reactors to monitor whether they are being utilized for energy generation or to create bombs.
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Because neutrinos flow through practically all matter unseen, they are frequently referred to as “ghost particles.” (Billions have already sped past your body today, on way from somewhere else in space, without your knowledge.) If you can capture them, they can inform you about what’s going on in their home universe as well as the basic features of the cosmos.
Scientists are particularly interested in learning about certain characteristics of neutrino activity, such as whether they have electromagnetic properties (for example, a “magnetic moment”) and if they interact with previously discovered particles or in novel ways with existing particles. It may be feasible to narrow down these options by taking thorough measurements of as many neutrinos as possible.
Collar’s team was drawn to nuclear reactors by the necessity for a large number of neutrinos. “By orders of magnitude, commercial reactors are the greatest generator of neutrinos on Earth,” he added. Nuclear reactors generate huge amounts of neutrinos each second in regular operation. They occur when atoms within the reactor disintegrate into lighter elements, releasing part of the energy as neutrinos.
There is, however, an issue. Because neutrinos are so light and interact so seldom, scientists usually have to seek for them by filling a massive tank with detecting fluids and looking for the telltale indication that a passing particle has caused one of many known reactions in it.
A multi-ton detector, on the other hand, would not fit inside a commercial nuclear reactor. Something much, much smaller was required by the researchers. Collar, fortunately, is a specialist in the field, having previously led a team that created the world’s tiniest neutrino detector.
In a second stroke of luck, Illinois is one of the top nuclear energy states, with nuclear reactors providing almost half of the state’s power. Collar was given permission to test the detector at Dresden Generating Station, one of the country’s first commercial nuclear facilities.
Collar and his colleagues had previously tested their small detectors at Oak Ridge National Laboratory in Tennessee, where they were able to precisely regulate much of the environment in order to get a decent signal. However, in order for the detector to operate in Dresden, they had to create a second version that was better suited to the considerably louder environment of a commercial reactor in operation.
Collar said, “You get radiation, heat, vibration from the turbines, RF noise from the pumps and other gear.” “However, we were able to overcome all of the obstacles that were in our way.”
To protect the detector from additional stray particles that may pollute the data, they constructed it with a complicated multi-layered shielding. They were eventually able to keep the detector running unsupervised for many months while collecting data.
The team plans to collect data at Constellation’s Braidwood Generating Station, as well as the Vandells nuclear station in coastal Spain, in the near future. Collar said, “This technology can substantially add to our knowledge of neutrino characteristics.” “Our data can be used to derive a lot of theoretical information.”
It’s also in great demand to know how to operate tiny detectors in such loud conditions. “The nuclear nonproliferation group is interested in installing detectors near reactors because they can tell you what’s going on in the core, indicating any deviations from the stated usage,” Collar added.
Because the emission of neutrinos varies depending on the kind of fuel used in the reactor and what it produces, detectors should be able to spot warning indications of weapons manufacturing or fuel being surreptitiously redirected elsewhere. However, such detectors would have to be tiny, sturdy, and simple to use in order to achieve this aim; Collar said the Dresden experiment helps collect vital data to make such detectors practical.
Neutrino detectors might potentially be used for a variety of different purposes. “For example, once we have sufficiently sensitive neutrino detectors, we might use them to scan the interior of the Earth—maybe even identify oil or other important reserves,” Collar said. “There has been a lot of thought along these lines, but it is still in the future.”
Collar was reminded while working on the design that his school laboratory is continuing a line of research started by Prof. Willard Libby in the 1950s to figure out how to utilize carbon-dating to determine the age of an item.
“To locate a relatively modest signal amid a huge number of background noise, these pioneers had to come up with strategies that we still use today,” he added. “It’s gratifying to know that our efforts are part of a long-standing local tradition. For these reasons, Illinois is a unique location for nuclear power production.”
University of Chicago graduate student Mark Lewis observes the compact detector next to the containment wall of the Dresden-II reactor. Credit: University of Chicago