Procuring and putting together the cables for these detectors has been a very long and difficult task.
One important change for this detector compared to previous generations is that the data (for CMS) is shipped out all on optical fibre. There are about 50,000 fibres to read the 10M channels of the tracker, and 10,000 fibres to read out the crystals for instance. Some of the detectors send out data which is digitized locally and serialized while others send out an analog signal which is converted to optical for transmission. All this optical cable reduces the noise seen in the detectors (from cross-talk for instance), and there is a lot less cable volume than we would have with copper.
Sadly we haven't yet figured out how to get the power in without using a lot of copper, so most of the cables are there to bring power to the detectors.
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Procuring and putting together the cables for these detectors has been a very long and difficult task. One important change for this detector compared to previous generations is that the data (for CMS) is shipped out all on optical fibre. There are about 50,000 fibres to read the 10M channels of the tracker, and 10,000 fibres to read out the crystals for instance. Some of the detectors send out data which is digitized locally and serialized while others send out an analog signal which is converted to optical for transmission. All this optical cable reduces the noise seen in the detectors (from cross-talk for instance), and there is a lot less cable volume than we would have with copper. Sadly we haven't yet figured out how to get the power in without using a lot of copper, so most of the cables are there to bring power to the detectors.