Scientists at Fermilab, located just outside Chicago, are making significant progress in building a powerful new beam of neutrinos for the Deep Underground Neutrino Experiment (DUNE). Neutrinos, often referred to as the “ghosts of the subatomic world,” have fascinating properties that make them difficult to study. They interact very weakly with ordinary matter and can change their identity, or flavor, as they travel. Understanding this behavior could provide insights into why our Universe looks the way it does.
DUNE aims to shoot a beam of neutrinos from Fermilab’s campus in Illinois to a detector complex located 1,300 kilometers away in South Dakota. The detectors will be housed at the Sanford Underground Research Facility (SURF), an abandoned gold mine in the city of Lead. The experiment will generate the world’s most intense beam of high-energy accelerator neutrinos.
The recent milestone achievement for DUNE was the completion of the excavation of the caverns that will house the detectors. Over the past three years, teams of miners have dug out nearly 1 million tons of rock a mile underground. The caverns span an area equivalent to about eight soccer fields. The next step involves installing all the necessary infrastructure, such as electricity, ventilation, and climate control, to prepare for the installation of the detectors themselves.
Once operational, DUNE will consist of four large detectors housed in three gigantic caverns. Each detector will contain 17,500 tons of liquid argon, which serves as the material to detect neutrinos. Argon is normally a gas but can be transformed into a transparent liquid when purified and chilled to extremely low temperatures. When neutrinos pass through the liquid argon, a small percentage of them interact and produce a flash of light and electrical signals. Scientists can analyze this data to determine the nature of the interaction and whether the neutrino changed its flavor during its journey.
The installation of the detectors is expected to begin after the infrastructure is in place. While prototype detectors have been successfully tested, the operational detectors are still under construction. The first detectors could start collecting data as early as 2028, with additional detectors coming online in subsequent years. The advantage of working with neutrinos is that they interact so rarely, posing no danger to researchers and construction crews. This allows for the installation of follow-on detector components while the initial detectors collect data.
DUNE’s primary goal is to study the transformation properties of neutrinos and their antimatter counterparts. Antimatter is a cousin of ordinary matter and interacts very weakly, similar to neutrinos. The experiment will produce a beam of muon neutrinos and observe how many transform into different flavors as they travel to the distant detector. This process will be repeated using a beam of antimatter muon neutrinos. The accepted theory, known as the standard model, suggests that the transformation properties should be the same for matter and antimatter neutrinos. However, if they are different, it could help explain the mystery of why our Universe is predominantly made of matter and not antimatter.
The first physics results from DUNE are expected to be available by the end of the 2020s. By studying the transformation properties of neutrinos and their antimatter counterparts, scientists hope to gain insights into the fundamental nature of our Universe and potentially solve the matter-antimatter mystery. The completion of the excavation of the caverns marks a significant step forward in this groundbreaking experiment, bringing us closer to unraveling the secrets of the subatomic world and understanding the origins of our Universe.