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ICARUS ( English Imaging Cosmic And Rare Underground Signals ) is a neutrino observatory , i.e. a large-scale physical experiment for the investigation of neutrinos . It is carried out in the Laboratori Nazionali del Gran Sasso (LNGS).

The experiment uses the further development of a type of particle detector proposed by Carlo Rubbia in 1977 , the Liquid Argon Time Projection Chamber (LAr-TPC). It should combine the advantages of a bubble chamber with an electronic readout process.

Several such detectors were built as part of the ICARUS program. In 2010 the ICARUS T600 detector in the LNGS with 760 tons of liquid argon was put into operation as the largest detector of its kind. To investigate neutrino oscillations and related fundamental questions, both neutrinos from astronomical sources and CNGS neutrinos (which are also used by the OPERA experiment ) are measured. The CNGS neutrinos come from the Super Proton Synchrotron at CERN at a distance of approximately 730 km. This is why the terms CNGS1 (OPERA) and CNGS2 (ICARUS) are also used.

The CNGS measurements also became significant when the OPERA group announced the alleged measurement of faster-than-light neutrinos in September and November 2011. The ICARUS group then published a study according to which the energy spectrum of neutrinos cannot be reconciled with the speed of faster than light. This was based on a work by Cohen / Glashow (2011), according to which intense bremsstrahlung in the sense of the Cherenkov effect would have to emanate from superluminal neutrinos ( vacuum Cherenkov effect ). In March 2012, the ICARUS group also published a direct measurement of the speed of seven CNGS neutrinos. The result agrees with the speed of light within the scope of the measurement accuracy. In August 2012, a more precise measurement was presented, which also corresponds to the speed of light. For details see measurements of neutrino velocity .

Web links

Individual evidence

  1. ^ Rubbia, C .: The liquid-Argon time projection chamber: a new concept for neutrino detector . In: CERN-EP / 77-08 . 1977.
  2. ^ ICARUS Collaboration: Underground operation of the ICARUS T600 LAr-TPC: first results . In: Journal of Instrumentation . 6, No. 07, 2011, p. 7011. arxiv : 1106.0975 . doi : 10.1088 / 1748-0221 / 6/07 / P07011 .
  3. a b ICARUS Collaboration: Measurement of the neutrino velocity with the ICARUS detector at the CNGS beam . In: Physics Letters B . 713, No. 1, June 18, 2012, pp. 17-22. arxiv : 1203.3433 . doi : 10.1016 / j.physletb.2012.05.033 .
  4. ICARUS Collaboration: A search for the analogue to Cherenkov radiation by high energy neutrinos at superluminal speeds in ICARUS . In: Physics Letters B . 711, No. 3-4, 2012, pp. 270-275. arxiv : 1110.3763 . doi : 10.1016 / j.physletb.2012.04.014 .
  5. ICARUS collaboration: Precision measurement of the neutrino velocity with the ICARUS detector in the CNGS beam . In: Journal of High Energy Physics . No. 11, 2012, p. 49. arxiv : 1208.2629 . bibcode : 2012arXiv1208.2629A . doi : 10.1007 / JHEP11 (2012) 049 .