Feedthrough Meeting 04/07/97

present:  P. Birney, T. Hodges, M. Lefebvre, P. Poffenberger

- News from BNL
  Michel talked to Dave Rahm.
  - They are busy producing the warm feedthroughs for the various
    test cryostats.
  - Looks unlikely that the full assemblies (this is what we are
    interested in following closely) will be done before end of
    September.

- Pof on vacuum system parts
  Pof is making great progress in getting quotes for various parts.
  In particular, varian and Leybold have given quotes for the
  "non-dry" He leak tester (about $CAN27k, not much less than the
  dry version).  Awaiting Balzers.

- Paul and Pof have investigated the time needed to pump down a 
  small volume from a rough out state (10**-2 mbar) to a state
  where the RGA multiplier could be turned on (10**-7 mbar).
  This is an important test for the viability of the use of the
  RGA as a quick turnaround leak tester.
  They have obtained about 3 minutes.  This is very encouraging.

- Paul and Pof on testing ideas
  Paul presented where his and Pof's thoughts were with respect 
  to the test setup.  The RGA (and ion pump) and the He leak tester
  will be centralised, with plumbing going to the warm tests on one
  side, and the cold tests on the other side.  
  - Warm tests:
    - Paul has a modular scheme for the warm tests that allow easy 
      switch between warm tests of pin carriers, flanges, bellows and 
      funnel.
    - Terry pointed out that we could envisage pressure tests at warm
      for the pin carriers.  This would also lead to an increased
      leak sensitivity.
  - Cold tests:
    - The current design (sketch distributed by Paul) allows for cold
      tests of the cold flange and funnel (with all the pigtails) alone, 
      or of the full assembly.
    - Michel and Dave Rahm have agreed that there is no need for us in
      UVic to test any mechanical movement of the bellows (this is a
      problem essentially limited to the barrel).
    - The cooling could use a combination of LN2 and the cryocooler.
    - We are not considering tilting anything, as done at BNL.
      After cool down and leak tests, we could put LN2 on the cold 
      flange, boil it off, and repeat the leak tests.  A few Watts
      of power could be provided by resistors at the cold flange
      attachment.  Needs careful thoughts with respect to the
      temperature gradient on the cold flange.
    - It was agreed that we should rough out the funnel (cold box) 
      before cooling.  Paul looking into including this in the design.
    - Michel reminded all that the security issue is important.  
      Effort should be made in the design to ensure as much as possible
      the security of the people using it (ie, as physicist proof as
      possible).

- We all agreed to start thinking about ways of keeping track of all the
  parts and tests that we will handle.  Paul mentioned the use of bar
  codes, or the use of engraving.  
  Michel reminded that tracability of parts is very important and must
  be possible at the end of the day.