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Michigan B184 Update January 14, 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
1. Summary table
N(total) N(finished) N(this week)
UM 80 79 0
BMC 80 0 0
UW 80 44 1
List of chambers finished this week: EMS3A08
2. Chambers in progress
EIL4C11: Taking CR data
EIL4A09: CR test done
EIL4C09: CR test done
EIL4C13: Taking CR data
EIL4A11: Fixed the leaks in bottom ML and recertified it.
EIL4C13: dealing with high dark current on tube ML1-1-54.
EML1A09: Taking CR data.
EML2C05: CR test done. Are testing T sensors and inplane system.
3. Problems and other issues
a) Crane operation. There has been a safety review and test on
moving the crane in Bldg180 and Bldg 184 right after the Xmas
break. This process seems has been finished. The operation in
Bldg184 formally started since last week. However, the moving of UM
chambers at Bldg180 is not yet unblocked. I heard that final process
like signature and documentation was not yet finished. Joerg is
making effort on this problem.
Its now not allowed to move two chambers together with the crane. Its
requested, and we agreed, that US must have one person there when
moving chambers in Bldg180.
b) Since EIL4 chambers are special, the determination of the T
sensors for them has been the bottleneck till yesterday. Matt is
now making an effort on this problem and we have to move over this
step so that these chambers that have past CR test could be moved
away, otherwise they occupy space and reduce our working efficiency.
c) Tube ML1-1-54 of EIL4C13 has high dark current, about 0.3 mA at
3.4kV. Negative HV didn't help getting rid of the high dark
current. We also cleaned the location between endplug and signal
cap. The resistance of the wire is normal (~138 Ohms, the same as
the nearby tubes). We are still working on this tube. If that is
still the case, this tube may has to be disconnected.
d) We are now working with UW chambers, mainly EIL4. a station with
2 BMC chambers with be set up this Friday. We will start working
with BMC chambers once Alex arrives at CERN.
We need to define the working package for BMC chambers. This will be
done with Alex after we work out 1-2 BMC chambers.
e) Attached is a file drafted by me, and discussed with all senior
personal who are participating the phase I work and at CERN so
far. A meeting was held to announce and discuss our task of phase I
for this year.
In summary, we have following work to be done at Bldg184 this year
UM:
a) 1 chamber to be moved back to change Mezz card and redo CR test.
b) ~25 chambers in Bldg184 need to modify the HV grounding, install
DCS box (about one week for 2 persons)
c) Repair EML4A07 chamber (dropped in Bldg180)
UW: Total 44 chambers to go, including the two H8 chambers that need
to be apply epoxy and recertify leak rate.
BMC: Total 80 chambers need to be reworked, including the two H8
chambers that need to replace tubelets, recertify leak rate. Working
package for BMC chambers need to be defined.
We now divided our chambers operators to three groups. On average,
each group needs to finish 2 chambers per week.
Also, please tell me who should be added to this e-mail list from each site.
Zhengguo Zhao