| CERN PhotoLab / Experiments and Tracks | CERN-EX-0302019 |
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Insertion of the first half-barrel of the ATLAS electromagnetic calorimeter into its cryostat
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The first cylinder of the ATLAS electromagnetic calorimeter barrel and the presampler have been inserted in the cryostat.The ATLAS electromagnetic calorimeter is intended to detect electrons, positrons and photons by measuring the energy they deposit on being absorbed. The cylinder of the calorimeter is in two halves, that will be sunk in a liquid-argon bath cooled to 90 kelvin (-180°C). Each half-barrel is 3.2 metres long, 53 cm thick and formed by assembling 16 modules. Each module is made up of alternate lead absorbers and electrodes pressed into 64 layers folded accordion-fashion. The presampler, set up inside the cylinder, is an integral part of the calorimeter system: It measures the energy lost by a particle before it reaches the calorimeter. To ensure an ultra-clean environment, a tent (visible here) was erected round the calorimeter and entry point to the cryostat. The detector and presampler, fitted together, could then be slid gradually into the cryostat like a drawer. To do so, the insertion team had to fine-tune the alignment of the rails in the cryostat and the guides on the calorimeter, with a high degree of precision. The system of hydraulic glides at the rail ends allowed the detector to be slowly moved into place. Here we see the calorimeter, prior to insertion, from inside the cryostat. The rails on the inner surface of the cryostat are clearly visible.
Photo 01: From left to right: Didier Laporte, Didier Steyaert, Jean-Pierre Recour, Gilles Decock and Michel Chalifour. Le calorimètre avant son insertion, vu depuis l'intérieur du cryostat. De gauche à droite: Didier Laporte, Didier Steyaert, Jean-Pierre Recour, Gilles Decock et Michel Chalifour.
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Total images: 2
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Record created 2003-02-27, last modified 2024-11-20
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