Scientists at DoE's Fermi National Accelerator Lab began a five-year project to explore neutrinos by sending a stream of them from the Lab west of Chicago to an abandoned iron mine in Minnesota.
They will travel almost 450 miles, going beneath Wisconsin, in 2.5 msec. And they don't need a tunnel. Subatomic neutrinos rarely interact with atoms of ordinary matter, so they pass through air, water, rocks, and people without a trace. The Main Injector Neutrino Oscillation Search (the Minos project) will probe the secrets of these elusive subatomic particles, which could explain how stars function. The subatomic particles could also one day be harnessed for communication or used like X-rays to explore the human body and search for oil and other minerals below the Earth's surface.
In the experiment, neutrinos produced at Fermilab's Main Injector accelerator will travel straight through the earth to a 6,000-ton particle detector a half-mile below the Earth's surface. The detector, a 5-kiloton magnetized tracking calorimeter, will search for neutrinos that may have changed from one type of neutrino to another during the trip. The 100 ft-long detector consists of 486 octagonal planes, each a sheet of steel 25-ft high and 1-in. thick, covered on one side with scintillating plastic.