Super Kamiokande

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Photomultiplier, National Museum of Nature and Science, Tokyo

Super-Kamiokande (also: Super-K ) is a neutrino detector that went into operation in 1996 near the Japanese community of Kamioka (today Hida ) and is the successor to the Kamiokande detector . As with its predecessor, it is hoped, in addition to the observation of neutrinos the proton decay observed. In 1998, among other things, data from Super-Kamiokande provided indications of the neutrino oscillation . The detector is also part of the Supernova Early Warning System .

Super-Kamiokande's detector consists of a tank filled with 50,000 tons of ultrapure water . This tank contains 11,200 photomultipliers from the Japanese manufacturer Hamamatsu Photonics , which register the Cherenkov radiation from free electrons and muons , which are created by the interaction of the neutrinos with the water molecules. The facility is located about 1000 meters below the earth's surface to shield off cosmic rays . The tank is divided, there are 32,000 tons of water in the center, 18,000 tons are in a shell around the center. This shell shields radioactivity from the surrounding rock and helps to distinguish muons from cosmic rays from electrons: muons can penetrate the wall between the inner and outer tank and are thus observed inside and outside. Electrons, on the other hand, generally cannot penetrate the wall. Therefore, the probability is very high that it is an electron that was only generated in the tank when Cherenkov radiation is only registered inside.

In November 2001, several thousand photomultipliers imploded in a chain reaction. The damage was then temporarily repaired and completely repaired in 2006, and measures were taken to avoid future photomultiplier failures.

Development started in the early 1990s after the success of Kamiokande. US scientists were also involved (including with parts of the Irvine-Michigan-Brookhaven experiment, which has expired ).

The spokesman for the collaboration and director of the Kamioka Observatory is Yōichirō Suzuki . The chief scientist in the detection of the neutrino oscillations was Yōji Totsuka .

The collaboration received the Asahi Prize in 1999 .

Hyper-Kamiokande

In 2011, plans were released for a successor to the Super-Kamiokande called Hyper-Kamiokande . In the summer of 2017, the Hyper-Kamiokande experiment was included in the MEXT roadmap of the Japanese government. The first experiments are planned for 2026 Template: future / in 5 years.

Web links

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  1. ↑ Claus Grupen: Astroparticle Physics: the universe in the light of cosmic rays. Vieweg Verlag, Braunschweig / Wiesbaden 2000, pp. 68-84 - 6.2 Neutrino-Astronomy , ISBN 978-3528031589
  2. ↑ JA Thomas, PL Vahle (editor): Neutrino Oscillations: Present Status and Future Plans. World Scientific Pub Co, Singapore 2008, pp. 19-43 - Chapter 2 - The Super-Kamiokande Experiment - by CW Walter , ISBN 978-9812771964
  3. ↑ Official report on the 2001 incident (PDF file in English; 167 kB)
  4. ^ The Hyper-Kamiokande Project is in the MEXT Large Projects Roadmap. hyper-k.org, August 4, 2017, accessed February 3, 2018 .
  5. ↑ arxiv : 1704.05933 .

Coordinates: 36 ° 25 ′ 0 ″  N , 137 ° 18 ′ 0 ″  E