DELPHI's end in site

17 May 2000

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As the Large Electron Positron (LEP) collider at CERN, Geneva, provides collisions at the highest energies the machine has achieved, the four big detectors - ALEPH, DELPHI, L3 and OPAL - are collecting their final burst of data before LEP shuts down in October, to make way for CERN's next machine, the Large Hadron Collider (LHC). The image above shows the symmetrical arrangement of components in the central "barrel" of the DELPHI detector. When in position in LEP, the pipe carrying the counter-rotating electron and positron beams passes through the centre of the barrel, which is seen here from one end. The detector stands over 10 m tall and altogether (including two end-caps which "close" the barrel) weighs 3500 tonnes. The segmented structure of the detector, with layers with different roles in identifying particles, is also seen in computer images of the particles detected, either in an "end view" or in a more 3-dimensional view.

Credit: CERN Photo