Minutes of the 3rd meeting of the Cooling Coordination Group  29-Apr-98

Present: P. Bonneau, J. Godlewski, G. Hallewell, S. Ilie, T. Niinikoski, A.
Onnela, H. Postema, M. Price, A. Smith, M. Wilhelmsson.

1. The minutes of the previous meeting were accepted.

2. Status of Phase I tests

Greg reported on recent tests carried out at Marseilles as well as on some of
the aspects of the recent ATLAS cooling meeting. The ATLAS pixel detector has
120 cooling pipes in all, 30 in and 30 out on each end. He had successfully
tested models of staves with -26 C input temperature. He mentioned that M.
Bosteels has proposed an under pressure fluorocarbon system. It was also hoped
to have an underpressure system for the liquid Argon calorimeter.
DELPHI had offered to supply free about 20 litres of fluoroinert for the
monophase tests. This liquid was not of sufficiently good quality to be used
in the DELPHI RICH but was quite acceptable for a cooling system. Greg also
reported that RAL was going to do some work on low temperature monophase
cooling, and Geneva University was already testing such a system.
  Tapio presented a draft document with his suggestions for what should be the
goals for the Phase I and Phase II tests. The Phase I part of this document
was discussed in detail. Tapio himself was setting up a spread sheet to
calculate the essential parameters of a cooling system and he planned to
produce initially figures for C3F8 and C4F10,  but the spreadsheet could be
applied to other liquids and gases of interest. Tapio's suggestion of
including detailed specifications for the final cooling plants in Phase I did
not meet with support. However it was pointed out that tests of prototype
structures had to be included in Phase I as this was part of the reason for
setting up the CCG.
  A lot of the equipment had been ordered for the monophase system of Antti
and Jan, and it was expected to be assembled by the end of May.  They expected
to continue their tests into September but should have most results available
by the end of July.
  CMS was not planning to participate in the evaporative cooling tests but
might adopt such cooling systems if the ATLAS tests looked good.
  The cooling system constructed by M. Bosteels for DESY would not be used in
the Phase I tests.
  Greg's C4F10 system could be moved to CERN from Mareseilles around the
middle of May. It appeared that this would be the optimum time for this to
happen. Tapio planned to complete his Phase I measurements by the end of May,
but after this, his set-up could be used for tests on structures by any
interested users. It appeared that the compressor he was using would not be
ideal for use with C4F10 where the input pressure was expected to be around
200 mb. This would need to be taken into account when interpreting any test
results.

It was agreed that it was essential that all Phase I tests be properly written
up so that conclusions could be drawn from the tests.

3. Phase II tests

This subject was dropped for lack of time.

4. Irradiation tests
 
  Hans had circulated some details on HFE-7100 by E-mail.
  Greg issued several information sheets on prefluorocarbons, some from DELPHI
on interaction with materials, and some on radiation effects.
  Sorin siad that he would be ready to make a presentation in late May on the
irradiation activation of fluoroinerts compared with HFE's and water. He would
then like to have plans made for testing the proposed cooling liquids after
irradiation, for corrosion, production of gases and modifications to
viscosity.

5. Next meeting

The next meeting will take place on Tuesday 26th May at 14h00 in B40 R-C10. It
should include the presentation by S. Ilie and perhaps also one on the results
of the CMS low temperature monophase tests.
  Members of the CCG are encouraged to think about what should be needed in
Phase II.

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