University of Minnesota's Ash River lab receives first neutrinos from Chicago
Scientists at the University of Minnesota’s remote underground laboratory near Lake Kabetogama in northern Minnesota say they have received their first-ever long distance neutrinos beamed from the Fermi National Accelerator Laboratory near Chicago.
It’s the world’s longest-distance neutrino experiment — with two huge particle detectors placed 500 miles apart and scientists trying to explore the properties of an intense beam of ghostly particles called neutrinos.
The lab, about 30 miles southeast of International Falls, has been in the works for a decade. The building is valued at $40 million, with the receiver costing upwards of $180 million.
“It’s nice to get it up and running and see that it works,” Alec Habig, University of Minnesota Duluth physicist working on the project, said Wednesday.
The first neutrinos were spotted with just 2 of the detector’s 14 units in place, Habig noted. When all 14 units are installed by the end of 2014, the neutrino detector will be even more sensitive.
Habig is a member of the NOvA collaboration, a group of 208 scientists from 38 institutions in the United States, Brazil, the Czech Republic, Greece, India, Russia and the United Kingdom. Habig is the convener of the “exotics” analysis working group with the Ash River project. His group analyzes the data to look for information that is out of the ordinary.
The experiment will last until at least 2020. But even then, researchers will only have caught about 5,000 neutrinos — fewer than two each day.
Neutrinos are called the ghosts of the universe because they have little or no mass, no electrical charge and tend not to interact with other matter. But they are everywhere — so numerous that even a small mass for each could have huge consequences for understanding the universe.
Any observed change of a neutrino between the three forms, called flavors, of the particle — electron, muon and tau — will allow researchers to begin calculating how much mass they might have. The two detectors of the NOvA experiment are placed so far apart to give the neutrinos the time to oscillate from one flavor to another while traveling at nearly the speed of light.
“Neutrinos could be the key to understanding why matter exists,” said Pier Oddone, director of the Fermi lab, said in a statement announcing the news.
Billions of the particles are shot out of a giant “gun” in the Chicago lab and sent through the earth every two seconds, aimed at the massive detector in Minnesota. The beam also is received at a similar but separate underground detector at the bottom of the Soudan underground mine near Tower, which has been in operation since 2005. Both receivers are operated by the University of Minnesota under a cooperative agreement with the Department of Energy’s Office of Science.
The beam of neutrinos is created by smashing protons into a graphite target, which releases a variety of particles. Scientists use magnets to steer the charged particles that emerge from the energy of the collision into a beam. Some of those particles decay into neutrinos, and the scientists filter the non-neutrinos from the beam.
The beam is aimed directly at the Soudan mine. The Ash River facility catches the edge of the beam, Habig said, which will add to scientist’s knowledge.
Different types of neutrinos have different masses, but scientists do not know how these masses compare to one another. A goal of the NOvA experiment is to determine the order of the neutrino masses, known as the mass hierarchy, which will help scientists narrow their list of possible theories about how neutrinos work.
The experiment receives funding from the U.S. Department of Energy, the National Science Foundation and other agencies