Feedthrough Meeting 22/08/97

present:  P. Birney, M. Fincke-Keeler, T. Hodges, 
          R. Keeler, R. Kowalewski, M. Lefebvre, 
          R. Langstaff, P. Poffenberger

- Feedthrough overall design
  - Terry received from Pailler French Pressure Code
    documentation.
    The plan is for Terry to agree on the pressures to be
    used for the final FEA, then to contact Pailler for
    approval.  Then to contact D. Rahm.
  - A set of Drawings is to be obtained from BNL early in
    September.
  - Terry is to run an FEA on the cooling rate on a flange
    with carriers. [done].
  - A note on Terry's FEA work can be found in 
    /user/lefebvre/endcap/feedthrough/fea
    and the subdirectories.
    In particular, the file fea.ps is the postscript file of the 
    document I have so far put together.  
    Let me know if you have problems reading it (be patient, 
    it is 33MByte in size).
  - Margret has made much progress understanding the cable budget
    for the feedthroughs.  Michel to meet with Margret to go
    over the list.
  - Margret made a very useful little maquette of the vacuum
    cables conected to the flanges, have a look!

- Trip to BNL
  - Richard distributed his notes from the BNL trip (Margret, 
    Richard and Ernie Neuheimer).
  - Richard proposed that we should produce a plot of the
    current per PA vs the total heat loss per feedthrough
    assembly for various kapton temperatures of the vacuum
    cable.  
    We could then present this to our colleagues and find out 
    the desired operating point.
  - Terry's latest FEA shows that with 208 mA/PA the kapton
    gets 60K hotter then the hottest end of the vacuum cable.
    Terry found that there are just enough pins allocated
    for low voltage transport to allow 208 mA/pins and satisfy
    MPI's proposed PA warm operating currents.  Some PA then
    require 2 pins, others 3, while most need only one.
    The vacuum cable used has full width signal traces.
  - Richard to prepare a note on the low voltage issue [done].
  - The total flex solution is now being investigated by
    Ernie.

- Leak Test Station
  - Paul presented his latest drawing of the leak test station.
    The discussion focussed on the test of the weld of the warm
    flange.  More study needed.
    The design is now at a stage where custom parts can be ordered 
    (two 6-way crosses, estimate US$950 a piece, Paul to investigate
    the procurement time).
    A list of needed off-the-shelf parts will be prepared.
  - Paul proposes tack welding during the assembly procedure, before
    proper weld is done.  It was pointed out that this might not
    be acceptable to the welder.  
    It was realised that welding considerations affect the assembly
    procedure and tooling.  We need to tackle the welding problem
    first.
  - Pof reported on his progress on the purchase requisition for
    the RGA gauges and leak detector package.  A package for
    $51.3k is prefered.  The order should be placed soon.

- PC and DAQ
  - Margret reported that both PC are up and running.
    Work has started on familiarisation to LabView.

- Electric Tests
  - Margret is to contact the "DC" testbox company for further
    information, in particular concerning an upcoming model
    controlable by computer.
  
- ATLAS meetings dates:
  - Sep 08 - Sep 12  :  Standard ATLAS week
  - Sep 15           :  GSC visit to UVic
  - Oct 06 - Oct 10  :  LARG week
  - Oct 13 - Oct 15  :  Feedthrough and Cryostats Review 
  - Nov 17 - Nov 21  :  Overview ATLAS week
  - Dec 08 - Dec 12  :  ??  LARG week  ??