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Special Gas Coordinantion Panel (Pressure Reg.)
Description
Present:
Rolf Lindner, David Mcfarlane, Christoph Schaefer, Sandro Palestini, Tom Meyer, Ray Gregory, Allain Gonidec, Stefan Haider, Serguei Konovalov, Anatoli Romaniouk , Ferdi Hahn
Short Recap of the Meeting:
Pressure Regulator Contract (details see transparencies):
For the adjudication CERN is considering two bidders (Zimmerli and Backofen). The problem is that the regulators from both companies do not give full satisfaction in terms of purity.
1) Zimmerli: has supplied two test regulators, one of them was tested in the chemical analysis and was accepted. The test revealed no silicon contamination, but non-negligible hydrocarbon pollution. Both regulators were tested in the TRT ageing setup and both failed with a moderate ageing rate of ~10% amplitude drop after 100h (acceptance threshold is 2% after 250h)
2) Backofen: has supplied also two regulators: One was tested in the chemical analysis, and was accepted (no silicon, but small hydrocarbon signal). The two regulators were tested in the ageing test, and both failed with quite large ageing signal (50% amplitude drop after 90h).
Following the presentations we had a long and controversial discussion on the acceptance of the regulators:
Ageing tests: both regulators failed the ageing test, though the Backofen gives a very large signal (which might not necessarily be due to Si contamination). The Zimmerli regulator causes a more moderate ageing, which might eventually diminish after further flushing. This has been experienced also for other components. More tests are needed to be more conclusive
Influence on the construction work: This regulator is needed for three modules (Mixer, Distribution and Pump), which are currently under construction. If this contract needs to be re-tendered changes on the construction program have to be done.
Comments from Experiments: Great scepticism from ATLAS, such components could be accepted for the RPC’s but not for the other systems. CMS, ALICE and LHCb are considering to proceed with at least the majority of their systems.
Conclusions and decisions:
It was decided to postpone the purchasing decision until the 1st of November. This will allow two things:
1) To contact the suppliers and understand more precisely their procedures for handling and cleaning, and eventually find a weak point that contaminates the devices (Follow up Ferdi)
2) To do further ageing tests with the devices after additional flushing (Serguei K.)
The Component Validation Policy:
The agreed procedures were re-presented (see transparencies).
FH.