KAMLAND
An international team of physicists completed construction on the KAMLAND
detector—short for Kamioka Liquid-scintillator Anti-Neutrino
Detector—in 1997 on the Japanese island of Honshu. KAMLAND detects
antineutrinos, the antimatter opposites of neutrinos, which signal the latter's
presence. The detector uses a telescope made of 1,000 tons of mineral oil and
benzene in a stainless steel tank two thirds of a mile below the Earth's surface to
measure antineutrinos issuing from nuclear power reactors and natural nuclear
reactions. In July 2005, KAMLAND scientists measured the Earth's total
radioactivity for the first time. Their findings will allow them to better
understand what keeps the planet warm, the volcanoes active, the continents
drifting, the magnetic field churning—all things that enable life. Until
this discovery, geologists relied on the reverberations from earthquakes to
estimate the planet's radioactivity.
