Difference between revisions of "Minutes-1-6-2011"

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December 16, 2010 FDC meeting
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January 6, 2011 FDC meeting
  
 
= Tentative Agenda =
 
= Tentative Agenda =
  
 
# Production (David)
 
# Production (David)
#* Blue Crab status [http://www.jlab.org/Hall-D/detector/fdc/pictures/Dsc05425_2.jpg]
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#* Blue Crab status [http://www.jlab.org/Hall-D/detector/fdc/pictures/Dsc05425_2.jpg picture before X-mas]
 
#* ETC change request for FDC [http://www.jlab.org/Hall-D/detector/fdc/budget/ETC_FDC_Tims_budget.pdf Tim's last schedule]
 
#* ETC change request for FDC [http://www.jlab.org/Hall-D/detector/fdc/budget/ETC_FDC_Tims_budget.pdf Tim's last schedule]
 
# Electronics (Fernando, Chris, Roger)
 
# Electronics (Fernando, Chris, Roger)
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#* Rigid-flex inspection
 
#* Rigid-flex inspection
 
#* Cathode foil production  
 
#* Cathode foil production  
#* Foil inspection report [http://www.jlab.org/Hall-D/detector/fdc/reports/Cathode_Foil_Inspection_Report_bills.docx report]
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#* Foil inspection [http://www.jlab.org/Hall-D/detector/fdc/reports/Cathode_Foil_Inspection_Report_bills.docx report]
 
#* Other  
 
#* Other  
 
# Engineering (Bill, David, Lubomir)
 
# Engineering (Bill, David, Lubomir)
 
#* Wire stringing table and movement system control
 
#* Wire stringing table and movement system control
#* Tension measurements [http://www.jlab.org/Hall-D/detector/fdc/pictures/Dsc05389_2.jpg], [http://www.jlab.org/Hall-D/detector/fdc/pictures/Dsc05400_2.jpg]
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#* Tension measurements [http://www.jlab.org/Hall-D/detector/fdc/pictures/Dsc05389_2.jpg], [http://www.jlab.org/Hall-D/detector/fdc/pictures/Dsc05400_2.jpg], [http://www.jlab.org/Hall-D/detector/fdclog/ FDC Log Book, page 548]  
 
#* Other
 
#* Other
# Full-scale prototype (Beni, Lubomir)
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# Full-scale prototype (Lubomir)
#* Studies with methane admixture [http://www.jlab.org/Hall-D/detector/fdclog/ FDC Log Book, page 545]
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#* Studies with methane admixture [http://www.jlab.org/Hall-D/detector/fdclog/ FDC Log Book, page 547]
 
# Other
 
# Other
 
<!--
 
  
 
= Minutes =
 
= Minutes =
  
Participants:  
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Participants: Bill, Fernando, Mike, Dave, Mark, Chris, Roger, and Lubomir.
 +
Mike is our new technician.
  
 
== Production ==
 
== Production ==
  
- Blue Crab status: the clean room construction started this week, walls are erected already.
+
- Dave: the clean room will be ready on Jan. 18, but then Jlab will do the wiring (power and internet) inside, which will bring us to the end of January. Right now Dominion Power is working on the power. In the mean time we will get a temporary staging area.  
  
- Wire frames (Bill): all wire frames inspected, we have 30 ready to go (out of 32), one is a little off the specifications, and another one is way off. Next step: gluing and laminating the PCBs that should start next week at Blue Crab. 16 cathode frames are ready; important is to check the depth of the O-ring groove.
+
- ETC change request: the package full tests are scheduled to start at the beginning of 2012, but will not have enough electronics for one package until Nov. 2012. At the other hand, the installation is supposed to start  at the beginning of 2013. Lubomir will discuss this with Tim.  
 
+
- New schedule: we discussed the feasibility of the package full tests scheduled to start at the beginning of 2012. For that we will need enough electronics to equip one full package: 12 F1TDCs, 36 fADCs, 24 anode and 108 cathode cards. According to Fernando we will have the cards and the fADCs by June 2012 and the F1TDCs by Sep 2012. Eugene looked at the last schedule for the electronics and concluded that actually we will have a good fraction of the electronics ready by the beginning of 2012. A delay is expected with the F1TDCs and we discussed options to replace those with other types of TDCs. Beni raised the question about the additional modules needed for the DAQ, since we are going to have at least two crates. All these questions require additional information from Fernando and other people, so we will continue the discussion off-line and on the next meeting.  
+
  
 
== Electronics ==
 
== Electronics ==
  
- Chris cleaned and tested with 2500V channel by channel all the first article PCBs. So, now we have two sets of PCBs ready to be laminated. For the cleaning, he used first Vigon bath but was not enough, so he did the final cleaning with Flux-off bottles. The rest of the PCBs that were sent back to the company for cleaning are still there. Fernando ordered two solder types for the wire soldering that we will test.  
+
- Chris: almost all the PCBs were tested channel by channel and all they are holding 2500V. They were cleaned very well. Fernando: the only operation that is needed is to fill the vias that were not sealed, with humiseal or epoxy. The only concern in doing this (Bill) is the thickness of the humiseal that is need; we need to make sure it doesn't interfere with the wires during stringing.  
  
- Roger who is now at the Allflex facility in Minnesota, informed us that the production of the first foils started. On Tuesday two panels were produced, one of them developed a wrinkle during the photo-resist stripping. We can still use such foils for practicing; it's good we have a lot of spare material. We don't know yet when they are going to ship the first article. Still, we decided to move two tables inside the Hall B clean room tomorrow afternoon, so that we have the place ready for the foil inspection.
+
- The first 25 rigid-flex boards have arrived. Fernando and Chris found them acceptable from electrical point of view. Bill will check mechanically how do they fit on the cathodes.  
  
- Bill informed us about accelerated aging tests done with the 3M conductive tape: the specialists are confident that it will last for 10 years, but the company is not going to state this officially. Bill will try another type (7303) of such tape that has pure epoxy.  
+
- Roger showed us pictures from the foil production at the Allflex facility. Bill had suggestions how to improve different procedures.
 +
 
 +
- We discussed the foil inspection report, linked above. Generally, the first article foils are acceptable but we have several remarks and requirements. Bill will work on the document and we will send it to Allflex a.s.a.p.
 +
 
 +
- Fernando: first article signal cables are arriving (40 in total) and Chris is going to check them channel by channel.  
  
 
== Engineering ==
 
== Engineering ==
  
- Wire stringing: almost all the parts needed for the stringing table are ready. Bill showed details on the attached to the agenda figures.
+
- Wire stringing: the micrometers have to be installed and we will be ready to start exercising. This is our first priority right now and we will start stringing on Monday. We need help with the software to control the movement system. Tomorrow a Parker representative will come to help us. Dave: if needed we may consider hiring him to write the software.
  
- The controller for the stepper motor should be here within a week. Two people representing Acuity were at JLab today demonstrating their laser sensors. It turned out that the new sensor that has higher sampling rate (9.6kHz compared to 1.2kHz that we have now) has bigger spot size and doesn't see the 25um wires on the first prototype. They proposed to use another two-dimensional sensor but it is not clear if it can see our wires, and also the price is high. Casey will string several field wires with the nominal tension of 20g directly on the granite table, and we will try to measure the tension using our old laser sensor.
+
- The tension on all the wires of a full-scale prototype wire frame (P2) were measured using our new procedure. These tensions were measured also at IUCF few years ago. The results are summarized at page 548 of the FDC logbook: apart from a ~5% systematic deviation, our result reproduces very well the IUCF measurements wire by wire. It means: 1)that our procedure is reliable, and 2) that the chamber tension didn't deteriorate during these years. The systematic deviation can be explained by the additional pins used now to stretch the wire frame on the strongback, or by some differences in the measurement procedures. Lubomir suggested to add adjustemnt of the magnet horizontal position, to make the wire oscillating strictly vertically. The main problem of the procedure is making contact with the wire pads. This can be improved on the HV side (Fernando) by using the HV pads and shorten the 1M resistors.
 +
On the readout side there were different ideas: clamping directly the wires (Bill) or even using the wires as they are with the weights and lifting one wire at a time with a hook to make contact (Lubomir).  
  
 
== Full-scale prototype tests ==
 
== Full-scale prototype tests ==
  
- Beni was working with 40/60 Ar/CO2 comparing fADC and F1TDC resolution. With this gas mixture, compared to 90/10, the resolutions are closer still F1TDC gives better resolution. We switched today to Ar/methane/CO2 gas. Beni is also implementing the new fADC125 library from Bryan Moffit. 
+
- Lubomir: in general using methane reduces significantly the after pulses. Bill: if we want to use methane it has to be discussed first with the safety people, so that we can have a plan for the gas system well in advance.
 
+
- Simon is studying the resolution for different gas mixtures with Geant simulations. Comparing 90/10 and 40/60 (pages 543 and 544) the spread of the drift time is smaller for 40/60 in the region up to 2mm, but bigger at 3-5mm. Expect more results for the next meeting.
+
 
+
== Other ==
+
 
+
- The Allflex company asked for permission to mention our detector in their trade journals and advertisements. Eugene will inquire about the procedure for such a permission.
+
 
+
-->
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Latest revision as of 19:44, 6 January 2011

January 6, 2011 FDC meeting

Tentative Agenda

  1. Production (David)
  2. Electronics (Fernando, Chris, Roger)
    • PCB inspection
    • Rigid-flex inspection
    • Cathode foil production
    • Foil inspection report
    • Other
  3. Engineering (Bill, David, Lubomir)
  4. Full-scale prototype (Lubomir)
  5. Other

Minutes

Participants: Bill, Fernando, Mike, Dave, Mark, Chris, Roger, and Lubomir. Mike is our new technician.

Production

- Dave: the clean room will be ready on Jan. 18, but then Jlab will do the wiring (power and internet) inside, which will bring us to the end of January. Right now Dominion Power is working on the power. In the mean time we will get a temporary staging area.

- ETC change request: the package full tests are scheduled to start at the beginning of 2012, but will not have enough electronics for one package until Nov. 2012. At the other hand, the installation is supposed to start at the beginning of 2013. Lubomir will discuss this with Tim.

Electronics

- Chris: almost all the PCBs were tested channel by channel and all they are holding 2500V. They were cleaned very well. Fernando: the only operation that is needed is to fill the vias that were not sealed, with humiseal or epoxy. The only concern in doing this (Bill) is the thickness of the humiseal that is need; we need to make sure it doesn't interfere with the wires during stringing.

- The first 25 rigid-flex boards have arrived. Fernando and Chris found them acceptable from electrical point of view. Bill will check mechanically how do they fit on the cathodes.

- Roger showed us pictures from the foil production at the Allflex facility. Bill had suggestions how to improve different procedures.

- We discussed the foil inspection report, linked above. Generally, the first article foils are acceptable but we have several remarks and requirements. Bill will work on the document and we will send it to Allflex a.s.a.p.

- Fernando: first article signal cables are arriving (40 in total) and Chris is going to check them channel by channel.

Engineering

- Wire stringing: the micrometers have to be installed and we will be ready to start exercising. This is our first priority right now and we will start stringing on Monday. We need help with the software to control the movement system. Tomorrow a Parker representative will come to help us. Dave: if needed we may consider hiring him to write the software.

- The tension on all the wires of a full-scale prototype wire frame (P2) were measured using our new procedure. These tensions were measured also at IUCF few years ago. The results are summarized at page 548 of the FDC logbook: apart from a ~5% systematic deviation, our result reproduces very well the IUCF measurements wire by wire. It means: 1)that our procedure is reliable, and 2) that the chamber tension didn't deteriorate during these years. The systematic deviation can be explained by the additional pins used now to stretch the wire frame on the strongback, or by some differences in the measurement procedures. Lubomir suggested to add adjustemnt of the magnet horizontal position, to make the wire oscillating strictly vertically. The main problem of the procedure is making contact with the wire pads. This can be improved on the HV side (Fernando) by using the HV pads and shorten the 1M resistors. On the readout side there were different ideas: clamping directly the wires (Bill) or even using the wires as they are with the weights and lifting one wire at a time with a hook to make contact (Lubomir).

Full-scale prototype tests

- Lubomir: in general using methane reduces significantly the after pulses. Bill: if we want to use methane it has to be discussed first with the safety people, so that we can have a plan for the gas system well in advance.