The Sun goes down on another successful season for IceCube
Work during the austral summer of 2006–07 ended on 15 February at the IceCube Neutrino Observatory at the South Pole. During a successful season, scientists and engineers positioned 13 strings of optical sensors deep in the polar ice. Each string carries 60 digital optical modules (DOMs), designed to capture evidence of cosmic neutrinos. This more than doubled the number of DOMs, taking the total to 1320 out of the 4800 sensors that will make up the observatory when it is completed in 2011 (CERN Courier May 2006 p24).
Despite the challenges presented by the extreme working conditions at the pole, the IceCube team made more progress than expected this year and is optimistic for future seasons. Another major accomplishment was the construction of the new IceCube laboratory, which houses the computers to collect, sort and store the data recorded by the DOMs. A small percentage of the most interesting data will be transmitted north via satellite, while the rest will be shipped to the US on magnetic tapes.
Physicists from more than 30 institutions in Belgium, Germany, Japan, New Zealand, the Netherlands, Sweden and the US are already evaluating the data from the DOMs installed so far. "With one fourth of the detectors already in place, we can do science now. We don't have to wait until 2011," says Francis Halzen, from University of Wisconsin and principal investigator of the IceCube project.
In addition to continuing to build IceCube, team members have also been studying the data taken with nine strings. A preliminary study has observed 234 neutrino candidates in 138 days of nine-string data, consistent with expectations for atmospheric neutrinos.
Israeli minister sees the progress on work on ATLAS
On 18 January, the Israeli minister of education, Yuli Tamir, visited CERN. She toured the hall where the muon chambers of the ATLAS experiment are being assembled, a project in which Israeli institutes are involved. She was then taken down into the cavern where the huge experiment is being installed, before a attending meeting with CERN's director-general, Robert Aymar. She also visited the Computer Centre.