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

2. 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

3. 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

4. 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

5. 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

6. 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

7. 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

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

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

10. 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

11. 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

12. 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

13. 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

14. Material Budget & Engineering for upgrade
Power cables
Current power cables are possibly at the practical limit of their current capacity (Total current more than 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

15. 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

16. 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

17. 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