The CMS Magnet Test and Cosmic Challenge (MTCC)
Operational Experience and Lessons Learnt
for the CMS collaboration
The CMS detector is under construction for imminent operation at the LHC machine at CERN. Since all the installation and commissioning is being done in a surface hall before all the disks and wheels will be lowered, and the magnet will be tested before lowering, a unique opportunity exists to operate all the sub-detectors and sub-systems together. This is called the MTCC – Magnet Test and Cosmic Challenge. The participating systems oinclude a 60 sector of the Muon System comprising gas detectors like the drift tubes,
cathode Strip Chambers and Resistive Plate Chambers, both in the Barrel and Endcaps. The tracking system comprises elements of the Silicon Tracker, Electromagnetic and Hadronic Calorimeter each subsystem participating at least at the 10% level. Other exercises include manouevering large elements of the detector, operation in magnetic field, coherent running of subsystems, operational and safety procedures.
Fig. 1: The ‘Cosmic Challenge’ participation of the CMS detector is seen; fig. 1a shows a sketch of the central barrel wheel with muon chambers, hadron calorimeter modules at ‘4 and 5 o’clock.’ In Fig 1b an overlap of the endcap chambers on the same sectors can
Fig. 2a shows the installed and commissioned endcap Muon Chambers; in fig 2b are shown cosmic muons measured with the CSCs.