A DELPHI end-cap undergoes a "re-fit"

24 May 2004

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Last week's image showed an "end view" of the "barrel section" of DELPHI, one of four detectors at the Large Electron Positron (LEP) collider at CERN, Geneva. The 10-m tall detector consists of the barrel plus two "end caps" which "close" the barrel. The image above shows one of the end-caps pulled away from the central barrel, during the installation of additional outer components. These were needed to ensure that all particles would be detected when LEP began to run at higher energies from 1996 onwards. The additional detectors (one is visible being raised to the left of the end cap) helped to identify muons, the only particles that would penetrate to the outer layers.

Credit: Physics Photographic Unit, University of Oxford