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
Neil Jackson
UK-V RAL 8th September 2004
1
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
Neil Jackson
UK-V RAL 8th September 2004
2
• 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!
Neil Jackson
UK-V RAL 8th September 2004
3
• 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
Neil Jackson
UK-V RAL 8th September 2004
4
Redundancy Link Results
• The inclusion of the redundancy links on disc 9 introduced additional
noise
• Investigations identified the following improvements
– Replacement of a 5kW resistor in the ground line with 0W
– An improvement in the redundancy link grounding
• For a full report see
http://hep.ph.liv.ac.uk/~ashley/Disk9_results_050804.pdf
Neil Jackson
UK-V RAL 8th September 2004
5
Extracts from the report
Neil Jackson
UK-V RAL 8th September 2004
6
Results with 0W resistor
+ new links still show a
distortion
at~ 0.3 fC
Occupancies look OK
Neil Jackson
UK-V RAL 8th September 2004
7
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
Neil Jackson
UK-V RAL 8th September 2004
8
• 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)
Neil Jackson
UK-V RAL 8th September 2004
9
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
Neil Jackson
UK-V RAL 8th September 2004
10
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
Neil Jackson
UK-V RAL 8th September 2004
11