Chamber production status

• 75% of production (of 1st half of detector) reached in May

• Currently ~80% is produced

• 100% (1st half) expected in October.

• End of chamber production expected early 2008

Problems• Unconnected pads/shorted pads:

– Reason: solder problems/carbon fibres connecting 2 channels– < 0.01% of channels affected

• Gain uniformity:– Some chambers (especially largest size) show worse uniformity than

expected.– So far no performance loss expected due to this, but discussion

ongoing.• Leakage currents due to glue:

– Change in formulation of hardener created leakage currents at edge of chambers

– Solution is cleaning of glue surface• First batch of chambers from Dubna (18pc.) damaged due to low air

pressure in plane:– Radiators cracked due to overpressure inside– All, but 2 chambers could be repaired.

Padplane design change

• Removal of copper of the outermost pads.– Reason: create

isolation barrier between anode HV and ground.

– No implications on acceptance.

– Change for 2nd half of detector

Edge of chamber

Chambers->Supermodules

• Chambers (from Bucharest/Dubna/Heidelberg) arrive at GSI. Storage area is available.

• Testing:– Individual testing of chambers in production site (full

set of QA tests)– Before Electronics equipping in Frankfurt, HV test will

be done (check for electrostatic sanity, after transport)– During assembly of SM: leak test of chamber layers.

So far no indication of transport problems.