Neutrino research

Weighty detector is unlocking secrets of the universe

A team of Tufts physicists has built a vital component of a 6,000-ton underground detector in northern Minnesota that will determine the mass scale of subatomic particles called neutrinos.

The Fermilab National Accelerator Laboratory

The mass is determined by measuring the interactions in the detector of neutrinos fired from the Department of Energy's Fermilab National Accelerator Laboratory near Chicago. Tufts is one of the founding institutions for this experiment, which is considered fundamental to advancing the field of elementary particles.

"We built an intricate switchyard for the optical signals from the detector that provide the picture of the neutrino interactions," said William Oliver, professor and chair of physics and one of the lead researchers. "The data will be fundamental to physicists and astronomers seeking to understand the building blocks of the universe."

The $300,000 optical switchyard that Tufts built was constructed by precisely guiding thousands of tiny fibers to the photodetectors that transform the optical signals to electrical signals. Neutrinos are subatomic particles that current research suggests change from one state to another among their three identities, similar to Clark Kent switching to and from Superman. They play an important role in the generation of energy in stars and other stellar objects.

In addition to Oliver, the Tufts team includes Jacob Schneps, Vannevar Bush Professor of Physics; W. Anthony Mann, professor of physics; and research scientist Hugh Gallagher. Schneps, a pioneer in this field, founded the Tufts High-Energy Physics Group in 1956 during a time of rapid development in physics research during the post-war era.

The Tufts physicists worked with Fermilab and other universities on the Main Injector Neutrino Oscillation Search project, known as the MINOS Experiment. It is the only underground neutrino project in the United States investigating the deepest structures of matter. (For more about MINOS, go to http://www-numi.fnal.gov).

Three years ago a team from the Tufts High-Energy Physics Group played a key role with Fermilab in proving the existence of the tau neutrino, the final member of the group of fundamental particles that comprise all matter.