CERN Neutrinos to Gran Sasso

The CNGS experiment ( CNGS stands for English CERN Neutrinos to Gran Sasso ) is a physical experiment that should provide important insights into the neutrino oscillation.

Design and function

At the SPS accelerator at the CERN research center near Geneva, a neutrino beam is produced, which then pass over a distance of 730 km through the Earth's interior to the Gran Sasso laboratory in Italy and will be detected there during the OPERA and ICARUS experiments.

Generating the beam, protons are shot on a graphite target in a helium-filled container with an energy of 400 GeV. The resulting positively charged pions and kaons are then focused by a magnetic lens system into a parallel beam and then disintegrate in a 1 km long evacuated tube to muon - neutrinos and muons. The resulting neutrinos retain their flight toward the Gran Sasso laboratory, while the remaining protons, pions and kaons are absorbed by an iron / graphite plate. The Myonenstrom, the same crosses the plate as the neutrinos is then measured in order to determine the number of dispatched neutrinos. Finally, the muons are absorbed by the rock and only the neutrinos continue their journey.

It is expected that some of the muon neutrinos traveling into other neutrino types convert (almost exclusively tau neutrinos ), which should then be detected by the OPERA detector. This evidence would mean an experimental confirmation of neutrino oscillation and allow their quantitative study.

History

The start of the experiment was originally planned for May 2006, after leaks in the hydraulic systems found the first two weeks of jet activity in October 2007.

In September 2011 it was announced by OPERA, that statistical analysis of measurements between 2009 and 2011 lead to the conclusion that neutrinos can travel faster than the speed of light. However, this measurement was faulty, and new measurements have correspondence with the speed of light arise. For more details see measurements of neutrino speed.