Neil JacksonUK-V RAL 8th September 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 JacksonUK-V RAL 8th September 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 JacksonUK-V RAL 8th September 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 JacksonUK-V RAL 8th September 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 JacksonUK-V RAL 8th September 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

Neil JacksonUK-V RAL 8th September Extracts from the report

Neil JacksonUK-V RAL 8th September Results with 0W resistor + new links still show a distortion at~ 0.3 fC Occupancies look OK

Neil JacksonUK-V RAL 8th September 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 JacksonUK-V RAL 8th September 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 JacksonUK-V RAL 8th September 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 JacksonUK-V RAL 8th September 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