Michigan B184 Update April 8, 2005

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Definitions of the numbers listed in Summary table:
N(total) = number of chambers to be worked or reworked at CERN in phase I
N(finished) = number of chamber that have been finished
N(this week) = number of chamber finished this week

1.  Summary table
              N(total)    N(finished)    N(this week)
UM             80            80               0   
UW             80            80               0         
BMC            80            30               8
-----------------------------------------------------
Total         240           190               8
                                                                 
2. Chamber finished this week: 

  BMC:  EIS2A02, 12, 14, 16;  EIS2C04, 06, 08, 10

3. Chambers in progress

  BMC chamber

    EIS2C12: HV/SHH cards mounted; dark current tested; installing Mezz
             cards and cables.
    EIS2C10: CR data taking
    EIS1C16: CR data taking
    EIS1C14: Waiting for updating mezz card DB to continue CR data
             taking.

4. Problems and other issues

  a) Mezz cards mounted on EIS1C14, EIS2C12 are not in the current
  data base we downloaded. Claudio is working on it, and Tiesheng has
  been informed. There are might be more chambers have the same
  problem and we cannot move on with these chambers before fixing the
  problem.

  b) ML1 HV tripped at 3080 kV, we opened the FC and found that for
  ML1-1-28 (HV side), the signal cap is too close (~1 mm) to a tubelet
  passing by it, causing HV trip. sometimes we can even hear the sound
  of sparking. We solved the problem by tuning the distance between
  the tubelet and the signal cap.

  c) It's very hard to change HV connectors for grounding, and deal
  with loose ETs, or change Mezz cards for these chambers due to the
  way how the chamber box was made. We are now trying to use the
  existing crane in Bldg184 to lift chamber out of box if
  necessary. However, if we use the frame from Boston, it needs to be
  safety certified, which needs quite some paper work and also takes
  long.  Dave and Curtis are thinking about a solution.

  Is the frame safety certified in Boston and do you have the
  document?

  d) The two dropped UM chambers (EML4A07, EML4C07) have been moved
  out of bldg184. EML4A07 went to 188 for x-ray tomograph and EML4C07
  to bldg180.

  e) B sensor test with EML1C11 chamber was not fully successful. We
  can test individual B sensor but not the chain with 2 or 4
  sensors. Claurnt from Saclay promised to do some test in his office
  and work with the relevant people. Then he will come back to test it
  next week. Bing is pushing hard to test B sensors since this is a
  work has never been really test in real life. Also Bing pushed hard
  to get 20 B sensors for the first sector.

  To test B sensor, one need to follow strictly the instruction, which
  Claurent promised to provide. The incorrect connection between
  cables and sensors will destroy the B sensor.

  Checking the B sensor platform position and direction is
  requested. 

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