Installation into CMS

The pixel detector was inserted into CMS after the installation and cabling of the silicon strip detector had been completed. The BPIX detector fits into the small volume limited by the outer radius of the beam pipe at 2.9 cm and the inner radius of the first layer of the strip tracker at about 21 cm. A system with bending rails on top and bottom inside CMS had been designed to insert the pixel detector and the supply tubes along the beam pipe. A clearance of 7-8 mm to the beam pipe had been calculated in simulations and checked with the help of a design model. The transport box with the pixel detector was placed on an insertion table and the rail system inside the box was joint with the rail system inside CMS using temporary extension rails (see Fig. 8.14). In this way, the pixel detector could slide out of the transport box into its final position. At the end, the service lines were connected at the so-called patch panel 0 (PPO) to the detector infrastructure. 

The detector infrastructure in the CMS cavern had to be ready well in advance of the detector installation. This included the installation and commissioning of the power supply system and the detector safety system. The cables and fibers between 

On April 25, 2008 the commissioning system was shipped to CERN and a test installation took place. The system was craned down to the cavern through the main shaft, lifted to the installation table and inserted into CMS. The installation of the commissioning system went smoothly and was finished within less than 4h. The power cables and the optical fibers of fhe equipped sector were connected at the PPO and the correct cable lengths were verified. The installation test did not reveal any need for mechanical adjustment before the final installation. 

The two halves of the BPIX final detector system were transported to CERN on July 15, 2008. After the transport, we tested the system in the surface hall at P5 and no additional damage was found. The installation of the final system started on July 23. Both halves of the detector were lowered into the cavern on the same day. The insertion of the inner shell was completed without any problems and all the connections were made, a total of 40 power and control cables and 18 multi-fiber ribbons. In order to make a fast check-out possible a temporary cooling system was set up. The second half of the BPIX detector was inserted the following day. The first attempt failed due to a collision of the detector end-flanges of the two detector halves. This problem was solved by mechanically modifying the suspension of the insertion wheels to enlarge clearance between the two half shells, and allowed us to finalize the insertion successfully. 

All power and control cables and all optical fibers of the BPIX detector were connected by July 24. A picture of the detector in the final position and the connection area PPO is shown in Fig. 8.15. The BPIX services had to be disconnected again when the final cooling tubes were joined and when the forward pixel detector was installed. 

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The detector halves together with the supply tubes were integrated in two 5 m long transport boxes custom-built for the installation into CMS. Within the transport box the detector is placed on wheels on a rail system which then can be used to slide the pixel detector inside CMS. A picture of the pixel detector with the two supply tubes inside the transport box can be seen in Fig.8.13. 

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