KamLandKamLand

By Roy Lehn

Omaha Roncalli

MeansMeans

Kamioka Liquid scintillator Anti-Neutrino Detector

Organizations InvolvedOrganizations Involved Nikolai Tolich Stanford University California Institute of Technology Drexel University IHEP, Beijing LBNL/UC Berkeley Louisiana State University Tohoku University TUNL University of Alabama University of Hawaii University of New Mexico University of Tennessee

Hungary Japan U.S.A.

HistoryHistory

Built in the mine that housed the pioneering Kamiokande experiment

After 4 years’ construction and oil filling periods, KamLAND started data taking on January 22, 2002

LocationLocationOn main island of HonshuTohoku university in Sendai, JapanThe detector is located 1000 meters

underground in the Kamioka Mine in Japan

The main goal will be to investigate the possibility of neutrino oscillations by studying the flux and energy spectra of neutrinos produced by Japanese commercial nuclear reactors

KamLAND is also studyingKamLAND is also studying

the disappearance of electron antineutrinos produced in nuclear reactors

Detect antineutrinos from uranium and thorium beta decays inside the earth

Nearly half of the planets heat is believed to come from such decays

The comparisons with similar measurements from Borexino to calculate the ratio of uranium to thorium in the crust and mantle of the earth

GraphsGraphs

Cool StuffCool Stuff It will be the first attempt to study the solar neutrino puzzle “in the

laboratory” It will be the largest low-energy antineutrino detector ever built Liquid-scintillator allows us to probe lower neutrino energies than

water Chernkov detectors It has a sensitive volume of 1000 cubic meters of scintillator The active scintillator volume is housed in a 2.5 m thick layer of ultra

pure mineral oil that shields it from external neutron and gamma radiation.

Scintillation light is picked up by an array of about 2000 specially developed photomultipliers achieving 3.5 ns time resolution using a very large (17 inch diameter) photocathode.

The liquid scintillator, buffer oil, and photomultiplier tubes combine to weigh 3000 tons (6 million lbs)!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

ScintillatorScintillator

Large light yieldHigh purityFast responseCheapSafe Systematic Uncertainty ~ 5%

ConclusionsConclusions

The detector has shown excellent performance

Further studies on background reduction are ongoing for 7Be solar neutrino detection.

The detector is bigIt’s operating right now

Questions???Questions???

Ask me or…

Bib.Bib.

Go herehttp://neutrino2002.ph.tum.de/pages/transpa

rencies/suzuki/index.htmlOr herewww.awa.tohoku.ac.jp/KamLAND/index.ht

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