The CMS electromagnetic calorimeter supermodule insertion tooling

Abstract

The CMS electromagnetic calorimeter (ECAL) barrel consists of 36 supermodules containing a total of 61,200 lead tungstate crystals. For the ECAL barrel integration it is necessary to develop a dedicated tool to insert the 36 supermodules into the Hadron calorimeter (HCAL) barrel via the rails that are fixed on the inner bore of the HCAL. The requirements on the insertion-tooling design are stringent the supermodules are fragile so all the operations, including the rotations to the right phi-positions, should be smooth; the tooling should have fine-adjustment facilities to avoid any kind of distortion on the supermodules. The CEA Saclay is responsible for the design and manufacturing of the CMS ECAL insertion tooling. The successful insertions of the first two supermodules carried out at the CMS experiment site in April 2006 showed that all the design requirements are fulfilled.