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Michigan B184 Update October 29, 2004 |
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1) Chambers re-working
a) Total number of chambers need to be reworked: 30
b) Total number of chambers that have been re-worked: 12
c) Chambers re-worked this week: EMS5A08, EMS5C16, EMS5C12, EML3A15,
EML3C01, EML4A09, EML4C09, EML4A01
Thanks to Li and Guocai, they worked so hard and effectively that
they managed to have this record.
2) Problems and other issues
- Manpower redistribution. Starting from this Monday, 3 our
students fully worked for UW chambers. Now 2 UW chambers are ready
for CR test.
UW has total 9 chambers that need to start from gas leak
certification, 44 chambers that need to be re-worked, of which 16
have no T sensor/inplane system cables.
- Generally speaking, the reworked UM chambers show good
quality. However, we found:
a. One string of T sensors failed re-test. We have to replace the
cable. The question is it was tested, how can this happen?
b. We found one hot channel/tube on EML4A11. The old data didn't
remove noise, and at that time we were suffering using mezz card
with large offset. This hot channel/tube was not easy to find
there.
Both chambers mentioned in (a) and (b) are early chambers.
- DAQ system for CR test. 3 are working fine. The 4th one has to go
back to the old version. Jeff tested it by mezz card HV on scan. We
have not used it to go through the entire process of CR test yet.
- CSM So far we have only 3 workable CSM1. So we cannot make full
use of the 4 daq system. it would be nice if we could have 5, one as
spare. It's crucial that we should have 4 fully workable DAQ
systems. This is particulary true once we start re-work UW chambers,
and then BU chambers since our predicted speed is 3-4 chambers per
day.
- Gas system in bldg 184. There was no gas last night. I urgently
called the CERN technical supporting group and we had gas this
morning. I also raised this question to Joerg. Since we re-work 8
chambers per week, gas system is also a key to us. So far we try to
prepare the chambers in such a way that we have chamber to be
flushed overnight, and other two chambers take CR data overnight.
- Chamber transportation. We had a big problem to get chambers in
time since bldg 180 was so busy that we could not get the crane for
our chambers. Fortunately we have 4 chambers in bldg157 and we
managed to have them, with great help from Joerg, Bernard.
After many rounds of pushing, we now have 10 chambers stored in bldg
184 and this will keep us alive for one week.
Zhengguo Zhao