Difference between revisions of "Minutes-2-23-2012"
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# Other | # Other | ||
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= Minutes = | = Minutes = | ||
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== Production == | == Production == | ||
− | - Dave: Deadened the first wire plane of package 3 with the larger diameter using the procedure with increased current and the same time as for the smaller diameter, but adding extra polishing cycle. Working on four cathodes now and on the last wire frame for the third package. One more cathode to finish the package. We | + | - Dave: Deadened the first wire plane of package 3 with the larger diameter using the procedure with increased current and the same time as for the smaller diameter, but adding extra polishing cycle. Working on four cathodes now and on the last wire frame for the third package. One more cathode to finish the package. There's not much space now to start the fourth package. Testing the chambers of the third package will be the bottleneck since it takes time to flush the chambers with gas. We will try to use weekends for that if possible. Third package was started partially end of November, so less than three months ago. Still we need to work on the subsystems for both package 2 and 3. |
− | - | + | - First cell of the third package was assembled yesterday, flushed with gas over night on today we were able to apply HV which by now is already the nominal one. The dark currents are very low. If it holds over the night we will assume that the wire deadening procedure works and we will continue tomorrow with the deadening of the next wire plane. Tomorrow also we will test the first cell and if everything is OK will try to assemble the second cell so that we can use the weekend to flush it. |
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+ | <!-- | ||
== First package testing == | == First package testing == | ||
− | - Beni showed results posted in the new FDC Elog linked above, entries #9-13 | + | - Beni showed results posted in the new FDC Elog linked above, entries #9-13. |
- Lubomir: good start for the first package, all wires working, no HV trips below 2150V with 50/50 Ar/CO2, while two channels tripped at 2200V which corresponds to a high gain of >10^5. Changing the HV from 2100/-500V to 2200/-500V (entry #12) improved the efficiency significantly. Now testing 21500/-500V. On the other hand we should try different ways to reduce the noise. One is to improve the LV distribution that contributes now to the noise problem due to voltage drops over the cables. After the meeting Beni installed new LV cables from Chris, one per plane, and the noise was reduced so that we have now 15V threshold. | - Lubomir: good start for the first package, all wires working, no HV trips below 2150V with 50/50 Ar/CO2, while two channels tripped at 2200V which corresponds to a high gain of >10^5. Changing the HV from 2100/-500V to 2200/-500V (entry #12) improved the efficiency significantly. Now testing 21500/-500V. On the other hand we should try different ways to reduce the noise. One is to improve the LV distribution that contributes now to the noise problem due to voltage drops over the cables. After the meeting Beni installed new LV cables from Chris, one per plane, and the noise was reduced so that we have now 15V threshold. |
Revision as of 19:37, 23 February 2012
February 23, 2012 FDC meeting
Agenda
- Production Construction Tracking (Dave)
- Production status
- Testing at Blue Crab (Lubomir)
- First package tests FDC ELOG (Beni, Lubomir)
- Engineering update[1],cooling manifold (Bill)
- Electronics update (Nick)
- Other
Minutes
Participants: Bill, Dave, Nick, Elton, Mark, Simon, Beni, and Lubomir.
Production
- Dave: Deadened the first wire plane of package 3 with the larger diameter using the procedure with increased current and the same time as for the smaller diameter, but adding extra polishing cycle. Working on four cathodes now and on the last wire frame for the third package. One more cathode to finish the package. There's not much space now to start the fourth package. Testing the chambers of the third package will be the bottleneck since it takes time to flush the chambers with gas. We will try to use weekends for that if possible. Third package was started partially end of November, so less than three months ago. Still we need to work on the subsystems for both package 2 and 3.
- First cell of the third package was assembled yesterday, flushed with gas over night on today we were able to apply HV which by now is already the nominal one. The dark currents are very low. If it holds over the night we will assume that the wire deadening procedure works and we will continue tomorrow with the deadening of the next wire plane. Tomorrow also we will test the first cell and if everything is OK will try to assemble the second cell so that we can use the weekend to flush it.