Status and Prospects of Tracker Services Hans Postema (CERN) 13 September 2007 Material Budget & Engineering for upgrade

Material Budget & Engineering for upgrade Services overview Cooling pipes Cables from power supplies Control power cables Optical fibres for readout and control Gas flushing pipes for inertion and humidity control 13 September 2007 Material Budget & Engineering for upgrade

Cooling pipes and cooling loops There are about 200 cooling loops installed This amount is a compromise between: Loss of detector surface when one loop fails, currently about 1 square meter Silicon detector per loop Increased system complexity due to a large number of loops Choice was well balanced when the concept was established 1 square meter of silicon was considered a maximum 200 loops was also considered the acceptable maximum System complexity is high. About 20 km of pipe was installed which took about 4 months despite serious schedule pressure. 13 September 2007 Material Budget & Engineering for upgrade

Cables from power supplies About 2000 cables Number of cables mainly a function of detector geometry, I.e. one cable per TOB rod. Average length 30 meters Installation of 60 km of cable, (more than 20 tons) is taking about 3 months despite high schedule pressure. 13 September 2007 Material Budget & Engineering for upgrade

Material Budget & Engineering for upgrade Control cables About 400 cables Average length 30 meters Installed together with Power Cables 13 September 2007 Material Budget & Engineering for upgrade

Material Budget & Engineering for upgrade Optical fibres 600 Optical ribbon cables with 8 ribbons, containing 12 fibres each The number of fibres is defined by the detector geometry and the fact that the entire detector is read out in an analogue fashion. Total length to be installed is 36 km Installation time is estimated as one month R&D, engineering, design etc. has consumed a total of 10 manyears. 13 September 2007 Material Budget & Engineering for upgrade

Material Budget & Engineering for upgrade Gas flushing pipes Flushing dry nitrogen or dry air to keep a low humidity level During operation, nitrogen is used for inertion (fire safety) During maintenance and shutdown, dry air is used (for safety of personnel) 24 pipes routed with cooling pipes (cold gas) 4 pipes routed for warm gas 13 September 2007 Material Budget & Engineering for upgrade

Material Budget & Engineering for upgrade YB0 Complexity (1) 13 September 2007 Material Budget & Engineering for upgrade

Material Budget & Engineering for upgrade YB0 Complexity (2) 13 September 2007 Material Budget & Engineering for upgrade

Material Budget & Engineering for upgrade Services conclusions A considerable amount of time and effort is invested in the current services The EB services are interleaved with the Tracker services Redoing TK services thus means dismounting, remounting and retesting of EB services, certainly not an elegant scenario. It seems unlikely that dismounting and reinstallation of new services will fit inside a “normal” say 6 months shutdown.. 13 September 2007 Material Budget & Engineering for upgrade

Material Budget & Engineering for upgrade The Question Can we envisage a new Tracker that uses the currently installed services? 13 September 2007 Material Budget & Engineering for upgrade

Material Budget & Engineering for upgrade Upgrade, assumptions Increased luminosity Increased data rate Increased power consumption Increased cooling requirements 13 September 2007 Material Budget & Engineering for upgrade

Material Budget & Engineering for upgrade Cooling The current Fluorocarbon loops are at the practical limit of their flow. Extra cooling capacity can be achieved by accepting a larger delta T. Generally this is not preferred since non uniform temperatures usually degrade detector accuracy. Possibly, another concept, such as a CO2 cooling can provide more cooling power with the same pipework. It seems useful to investigate the options. 13 September 2007 Material Budget & Engineering for upgrade

Material Budget & Engineering for upgrade Power cables Current power cables are possibly at the practical limit of their current capacity (Total current more than 15.000 Amps) If future electronics operate at lower voltages, even the same power consumption would pose problems. The current cables could probably safely operate at a somewhat higher voltage. It seems useful to investigate the possibilities of powering circuits in a serial way. 13 September 2007 Material Budget & Engineering for upgrade

Material Budget & Engineering for upgrade Optical fibres Currently the optical fibres transmit analogue signals. It is estimated that by using digital signals, the installed fibres have sufficient bandwidth for the SLHC data rates. 13 September 2007 Material Budget & Engineering for upgrade

Material Budget & Engineering for upgrade Control power cables Quantity and composition are a direct results of the current detector layout Difficult to estimate how they could be used in an upgraded detector Cables are smaller and fewer than main power cables Could envisage installing additional cables of this type, on top of or between the currently installed services 13 September 2007 Material Budget & Engineering for upgrade

Material Budget & Engineering for upgrade Gas flushing pipes Most likely fully sufficient for a next generation Tracker. 13 September 2007 Material Budget & Engineering for upgrade