| The Main Injector Neutrino Oscillation Search, or
MINOS experiment, located
half a mile underground in the historic
Soudan iron
mine in northeastern Minnesota, will probe the secrets of
subatomic particles called
neutrinos . The neutrinos will be produced by a particle
accelerator at Fermi National
Accelerator Laboratory" near Chicago. Beginning in February
2005, neutrinos in the NuMI (Neutrinos at the Main Injector) beam
will be directed 450 miles straight through the earth, from
Fermilab to Soudan--no tunnel needed.
In Minnesota, a 6,000-ton steel detector will search for
neutrinos that have changed from one kind to another during the
split-second trip. More than a trillion man-made neutrinos will
pass through the MINOS detector each year. Because neutrinos
interact so rarely, only about 1,500 of them each year will
collide with atoms inside the detector. The rest will pass through
with no effect. The 200-plus MINOS
experimenters will use the change from one type of neutrino to
another as the key to unlocking neutrinos' secrets: Where do they
come from, what are their masses and how do they change from one
kind to another? How are neutrinos related to the mysterious
dark matter that makes up almost a quarter
of our universe? |
