|
|
Michigan B184 Update July 15, 2005 |
Back to B184 updates * Previous * Next
ALL US MDT CHAMBERS FOR THE PHASE I HAVE NOW COMPLETED PHASE I!
We very much appreciate all who contributed to this work.
1. Phase I
EIL1C09, EIL2A03, EIL2A11 finished CR test and phase 1.9
work.
UW:
Four BIM chambers: HV cards from Italy have arrived and been
installed. UW people are responsible for working on these
chambers.
2. Phase 1.9
Four chambers are doing photogrammetry.
3. Problems and other issues
i) EIL2A11 has a sunk (low-efficiency?) region about 40 cm wide. The
maximum drift time of about 20 tubes in this region, most of the ML1
are about 20-40 ns longer than that the normal tubes, even after we
have done pressure recycling 7 times.
The longer drift time became shorter and shorter after flushing more
and more gas. We kept this chamber in B184 for further study of this
problem.
ii) EMS5A08 has cracks on endplugs of 9 tubes. Since there are over
100 endplugs of the same batch used, we decided to apply DP190 epoxy
to the endplugs of ALL tubes of this chambers. 5 days' measurement
of the leak rate done (by Bingyun) since 7/12 gives the results of
0.78 and 1.13 mbar/day for ML1 and ML2, respectively. So the gas
tightness for this chamber is still pretty good.
iii) I think it's a time for me to sign off sending you the weekly
report since phase I work is done.
Zhengguo and David