Prof. Werner Tornow spent two and a half weeks in Japan to help with the refurbishment of the so-called Outer Detector of the main KamLAND detector located in the Kamioka mine adjacent to the Super-Kamiokande detector. The Outer Detector was built with Prof. Tornow as Principle Investigator in the years 2000 and 2001 by members from the TUNL consortium using funds provided by the United States Department of Energy. The Outer Detector is a water Cherenkov detector employing 225 large (20” diameter) photomultiplier tubes, which were recycled from the old Kamiokande detector. During the past decade more than half of these photomultiplier tubes failed, reducing the efficiency for vetoing cosmic-ray muons to a level unacceptable for another decade of operation. Therefore, the Japanese government provided funds to install 140 new 20” photomultiplier tubes. After discovering neutrino oscillations and detecting anti-neutrinos from the Earth’s crust and interior, the main research thrust of the KamLAND collaboration is now focusing on the search for neutrinoless double-beta decay of 136Xe.
PHOTO on right: Prof. Tornow (left) and the Japanese team during a break on the KamLAND Outer Detector refurbishment work.