Background Suppression
Most neutrino experiments must address the flux of cosmic rays that bombard the Earth's surface. The higher energy (>50 MeV or so) neutrino experiments often cover or surround the primary detector with a "veto" detector which reveals when a cosmic ray passes into the primary detector, allowing the corresponding activity in the primary detector to be ignored ("vetoed"). For lower energy experiments, the cosmic rays are not directly the problem. Instead, the spallation neutrons and radioisotopes produced by the cosmic rays may mimic the desired physics signals. For these experiments, the solution is to locate the detector deep underground so that the earth above can reduce the cosmic ray rate to tolerable levels.
Read more about this topic: Neutrino Detectors
Famous quotes containing the words background and/or suppression:
“They were more than hostile. In the first place, I was a south Georgian and I was looked upon as a fiscal conservative, and the Atlanta newspapers quite erroneously, because they didn’t know anything about me or my background here in Plains, decided that I was also a racial conservative.”
—Jimmy Carter (James Earl Carter, Jr.)
“Fashion required the suppression of all naturalness—’to walk upright, with unbending joints; to shake hands after the pump- handle formula; to look inexpressibly indifferent towards everybody and everything; and speak only in a mincing voice was to be a decorous member of society.’”
—For the State of Rhode Island, U.S. public relief program (1935-1943)