Michigan B184 Update April 29, 2005

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                   43                    3
-------------------------------------------------------------------
Total         240                  203                    3

2. Chambers finished this week:

  BMC:  EIS1A02, EIL2C01, EIS1A06

3. Chambers in progress

  BMC chamber
    EIL2A01: CR data shows one low efficiency channel. Reason needs to
             be found. (usually due to the foam on SHH socket pin)
    EIL2C13: CR data shows that three tubes have about 50 ns longer
             drift time. These tubes are in the region where gas is
             from the bent copper tube. Flushing more gas improves the
             drift time. We found one needs to flush much more gas so
             that the drift time of the tubes in this region is
             normal.
    EIL1C13: Dark current test.

4. Problems and other issues

  a) Two UW students are now working for the 8 BIM chambers that will
     be attached to EIL4 chambers. We also need to help phase 1.9 to
     set up the working area and worked on three chambers together
     with Alex and the student with him.

  b) For EIL1 chambers, after installing gas connection to the ETs, we
     need to certify the leak rate. The certification time is usually
     over night, around 16 hours.

  c) EIL2 chambers have a step and the gas flow has a high impedence
     due to the copper tubing. This cause long drift times for the
     tubes in this region if we use the usual way to flush the chamber
     with gas.

  d) Both EIS1A06 and EIL2A01 have one channel with low efficiency. We
     fixed one by replacing the SHH card. The other one is under
     study. We know this usually caused by the foam on the SHH socket
     pin.

  e) We started to use the CSM4 for the CR test. A difference in
     charge distribution was observed, probably due to a JTAG
     parameter difference, according to Jay. Jay has arranged Tiesheng
     and Jeff to work on the issue.

  f) Rick finished replacing the tubelets on one ML of EIL1A9 (one of
     the two H8 chambers).  He and Dave also have installed copper
     tubing to the ETs on 8 chambers.  The other BMC H8 chamber is
     still at H8.

  g) The platform of bldg184 has to be freed for trucks.  We then have
     to arrange a buffer zone to store some chambers so that we can
     continue working on chambers as usual.

Zhengguo and David
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