Module to Disc Assembly

Neil Jackson UK-V RAL 8th September 2004 1

Module to Disc Assembly

• Infrastructure

– Services and test box

– Evaporative cooling system

– Disc Handling

• Tests on disc 9

– Redundancy link results

– Cooling performance

• Current Inventory

• Future plans


Infrastructure• Services and test box

– Optical Fibres and DCS in place– Test cables terminate in patch panels

allowing the connection to PPF0 through a short length of ribbon cable

– Test box is equipped with simple removable aluminium covers front and back


• Evaporative cooling system

– 4 heat exchangers have been constructed

– Pipe-work, valves and distribution blocks have been installed

– Connections are made using flexible stainless steel pipe-work

– Leak testing is very time consuming!


• Disc Handling– The disc handling jig

using the crane has been modified to optimise the smooth attachment and removal of discs for both the mounting tooling and the test box

– Further modification will be required for transferring the disc to and from the tooling to mount the disc in the end-cap cylinder


Redundancy Link Results• The inclusion of the redundancy links on disc 9 introduced additional

noise

• Investigations identified the following improvements

– Replacement of a 5k resistor in the ground line with 0– An improvement in the redundancy link grounding

• For a full report see

http://hep.ph.liv.ac.uk/~ashley/Disk9_results_050804.pdf


Extracts from the report


Results with 0W resistor + new links still show a distortion

at~ 0.3 fC

Occupancies look OK


Cooling Performance• The cooling system tests have involved running the Cold

Room with a low dew point (<-25C) but operating at room temperature– Test box is flushed with dry air

• The evaporative cooling for Disc 9 was turned on quadrant by quadrant (no power load)– Each quadrant will cool down to –25C but when all

four operate together one quadrant was not cooled efficiently

• The suspect heat exchanger has been replaced– All quadrants now cool together to –25C– Need to check performance with power on all

quadrants


• One problem is that the programmed switch-off mode for the cooling rig allows the temperature to fall to –40C– Simple cure is to enter the cold room very briefly and

close valves feeding the disk– Can also investigate possibility of modifying the code

in the controller• 8 Hybrids and 4 modules were mounted without thermal

grease, powered and clocked with ambient temperature of ~20C– the hybrids temperatures varied between 6C and 13C

(Ambient in test box ~ +10C)– Hybrids ran cooler ~ 6C-8C, modules at ~12C-13C

• Modules with grease run ~ 5C cooler (ambient ~ 20C)


Current Inventory

• Disc 9C has been accepted and is in use

• Disc 8C has arrived and is awaiting acceptance tests

• Disc 7C is expected next week

• In terms of modules we currently have in Liverpool

– 171 (Good + Pass) outer modules

– 76 (Good + Pass) Middle modules

– 15 Outers and 29 Middles being processed


Future Plans

• There is a proposal to mount the least good modules on Disk 9 (~10 bad channels)

• Next step is to mount all the lower modules using correct tooling and thermal grease

– Electronic characterisation

– Thermal tests with thermal camera

• Mount the remaining modules and characterise a completed disc

• In parallel perform acceptance tests on discs 8 and 7

Module to Disc Assembly

Documents

Transcript of Module to Disc Assembly