Studies of data transmission on long polyimide cables

Tracking detectors for ATLAS and CMS experiments will have to be replaced after an LHC luminosity upgrade, due to radiation damage and more stringent performance requirements. The new sub-systems will be larger in scope of instrumented area, and therefore will feature more tightly integrated modules. A basic building block of both strip and pixel sub-systems of the ATLAS Upgrade is the ¿stave¿, a collection of modules with common mechanical support, thermal management system and readout. The data readout is planned to be done via thin polyimide cable which covers the full length of a stave, of up to 1.2 m, and supplies data I/O for each module. The large number of modules placed on the stave, and large track multiplicity at the upgraded detectors necessitate faster readout speed than in present ATLAS detector. We are investigating the signal integrity in polyimide cables at 160 and 320 Mbps, and as a function of system parameters in order to determine the plausibility of using the cables as the data transport method of the staves for the ATLAS Upgrade.