Difference between revisions of "Minutes-3-24-2011"

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== Production ==
 
== Production ==
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- Dave: The first test cathode was finished using a "good" third panel. It will be tensioned nest week. The PC used for tensioning was fixed by the CC. The stringing table is now in the clean room. Some additional fixes on the strongback are needed and will be done separately outside of the clean room.
 
- Dave: The first test cathode was finished using a "good" third panel. It will be tensioned nest week. The PC used for tensioning was fixed by the CC. The stringing table is now in the clean room. Some additional fixes on the strongback are needed and will be done separately outside of the clean room.
  
 
- Bill is ready with the FDC drawings needed for the review, except two on which Rich Getz is working. Dave is working on the procedures. We will post for the review all the procedures
 
- Bill is ready with the FDC drawings needed for the review, except two on which Rich Getz is working. Dave is working on the procedures. We will post for the review all the procedures
−
needed to start the production even if some of them are nor approved yet. The main reason is that there are some details and parameters reflecting the new design that can be establish only during the production of the first chamber layer. Still these procedures are needed for the review even if they may be changed. Bill will work on "FDC CUTTING CATHODE FOIL HOLES AND SLOTS", "FDC CATHODE GROUND FLAPS AND PANEL CONNECTIONS", "FDC END WINDOW GLUING AND TENSIONING" and also on cathode and ground tensioning, the latter require information from the tensioning done before. Dave will take care of "FDC WIREPLANE CUT WIRES AND REMOVE TAPE", "FDC FABRICATE O-RINGS", "ATTACHING THE DAUGHTER CARDS TO CATHODE FRAME", and "ATTACHING THE DAUGHTER CARDS TO THE CATHODE FOIL". We decided in the latter procedures to assume using conductive tape, of course later we can modify it if it is needed. Beni will work on "SINGLE LAYER TESTING" procedure, and Lubomir on wire position and tension measurements. Depending on the needs, Lubomir and Beni will help Dave with the other procedures, as well.  
+
needed to start the production even if some of them are nor approved yet. The main reason is that there are some details and parameters reflecting the new design that can be establish only during the production of the first chamber layer. Still these procedures are needed for the review even if they may be changed. Bill will work on "FDC CUTTING CATHODE FOIL HOLES AND SLOTS", "FDC CATHODE GROUND FLAPS AND PANEL CONNECTIONS", "FDC END WINDOW GLUING AND TENSIONING" and also on cathode and ground tensioning, the latter require information from the tensioning done before. Dave will take care of "FDC WIREPLANE CUT WIRES AND REMOVE TAPE", "FDC FABRICATE O-RINGS", "ATTACHING THE DAUGHTER CARDS TO CATHODE FRAME", and "ATTACHING THE DAUGHTER CARDS TO THE CATHODE FOIL". We decided in the latter procedures to assume using conductive tape, of course later we can modify it if it is needed. Beni will work on "SINGLE LAYER TESTING" procedure, and Lubomir on wire position and tension measurements. Depending on the needs, Lubomir and Beni will help Dave with the other procedures, as well. Dave has updated the QA plan waiting now for signatures. As for the safety documents, linked also at the review page, Bill asked about the flammability of the ethanol we want to use to clean the wireframes in the ultrasonic cleaner. Example: 40% ethanol solution with water is flammable at 26degC. Need the help of the EH&S people for that. 
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== Electronics ==
 
== Electronics ==
  
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- Chris: expects the parts for the rigid-flexes soon. As of now, in the Gerber files, the flex contacts are tinned but we have not decided yet about that (see discussions of the flex gluing below). We have received 34 signal cables that were re-worked and are one feet shorter. Soon we will receive the rest 16 of the first article.  
+
- Lubomir explained the need to have testing step pulse with a variable amplitude from fADC125 fed on the pre-amps to easily check the linearity of the electronics. Gerard and Fernando are needed for this discussion.  
  
−
- Roger: no news from Alflex, expecting the next set of panels by March 25.  
+
- Beni learned that for the discriminator boards there's already a translator from LVDS to ECL used in Hall B. So the design exists and we just need to make several for our FDC package tests. Chris will discuss it with Fernando.
  
−
- Fernando was not at the meeting and we didn't discuss the fADC125.
+
- Chris: all the 34 signal cables arrived and have been tested: all are OK. Another 16 will come soon. As for the tinning of the rigid-flex cotacts he wanted to know when we will decide about the technique of the soldering. Bill thinks that one can use conductive tape even with tinned contacts. To test this we will tin three flexes manually, solder them using conductive tape, and do the same tests as with the non-tinned samples that we have already.
  
 
== Engineering ==
 
== Engineering ==
  
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- The second attempt to glue the flex to the cathode using conductive tape was successful. A sample was shown at the meeting. In the previous attempts the flex was glued to the wrong side and as a result connecting all the signal traces to the cathode ground, while the ground traces were connected to the rigid-flex ground. Still, in the first trials one could check some of the connections and they were not OK. The important now was that Casey was able to align the connector pins by using back-light through the g10 plate. Aslo we used thermal conductive silicon to make the pressure over the contact more equal. Later, however, we saw we had an epoxy blob on the back of the g10 that made the plate not parallel to the surfaces of the tool. So, maybe the procedure will work even without conductive silicon.  
+
- Bill was working on some tooling: for sanding the outer 3mm of the Rohacell on the wire frames (ready), for the wire stringing sensors, and also on the new jig table that will be used for the package assembly. We decided that at the beginning, for the package assembly we will use the existing jig plate and the gusset from the prototype.
  
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- To investigate the longevity of the gluing there were several suggestions. Eugene: to put the sample in and out of the fridge for several days and check it. This will simulate temperature and also (Beni) humidity changes. The radiation effects can easily be studied in HallA/C; one day there will be equivalent to tens of years at Hall D. Our techs will make more samples for testing. Any other suggestions to investigate the life time of the conductive tape gluing are welcome. This procedure will save us a lot of time and troubles, but the main question now is how reliable it is. In that respect we will postpone the decision about the flex tinning and Chris will inform the vendor about that possible change.
+
- So far we have 5 samples with conductive tape putting them daily in and out of the fridge. To accelerate the testing we will try some extremes: putting the samples in liquid N and also in hot water. Eugene was skeptical about the value of such tests, assuming they will not pass. Still it doesn't hurt to try it with some of the samples. Beni will contact target group to help with the liquid N.
  
 
== Chamber testing ==
 
== Chamber testing ==
  
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- Beni made some improvements in the testing set-up adding more amplifiers to the external Indiana chambers. Now we can cover almost the whole FDC chamber but we need also another F1TDC module.
+
- Lubomir is analyzing the data from the scan of one half of the prototype after calibrating the strips. The relative calibration is based on the fact that the top and bottom strips see the same charge and that one top (or bottom) strip from one card "crosses" all the bottom (or top) strips from another card. After the calibration the position resolution improves by ~20%. It was found also that two strips (out of 192) are not showing signals. We are considering to open the prototype chambers soon after the review. For that we may want to use the jig plate to transport the prototype to Blue Crab where it will be opened.
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+
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- Lubomir finished with the scanning of the prototype as it is upside-down. He showed a 3D plot for the top/bottom strip asymmetry at standard and upside-down positions. It clearly shows the effect goes with the gravitation and is maximal in the middle of the chamber. There's some "fine" structure visible for all the runs that can be flattened out by improving the electronics calibration. One can upturn the problem: the ratio of the top/bottom strips can be used to calibrate the electronics. Including in addition the wire amplitudes one will have redundancy and thus a good cross-check.
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Latest revision as of 16:13, 7 April 2011

March 24, 2011 FDC meeting

Agenda

  1. Production
  2. Electronics (Fernando,Chris)
    • fADC125
    • Other
  3. Engineering (Bill)
    • New tooling
    • Conductive tape gluing
    • Other
  4. Chamber testing
    • Electronics calibration (Lubomir)
  5. Other

Minutes

Participants: Bill, Dave, Chris, Simon, Beni, Eugene, and Lubomir.

Production

- Dave: The first test cathode was finished using a "good" third panel. It will be tensioned nest week. The PC used for tensioning was fixed by the CC. The stringing table is now in the clean room. Some additional fixes on the strongback are needed and will be done separately outside of the clean room.

- Bill is ready with the FDC drawings needed for the review, except two on which Rich Getz is working. Dave is working on the procedures. We will post for the review all the procedures needed to start the production even if some of them are nor approved yet. The main reason is that there are some details and parameters reflecting the new design that can be establish only during the production of the first chamber layer. Still these procedures are needed for the review even if they may be changed. Bill will work on "FDC CUTTING CATHODE FOIL HOLES AND SLOTS", "FDC CATHODE GROUND FLAPS AND PANEL CONNECTIONS", "FDC END WINDOW GLUING AND TENSIONING" and also on cathode and ground tensioning, the latter require information from the tensioning done before. Dave will take care of "FDC WIREPLANE CUT WIRES AND REMOVE TAPE", "FDC FABRICATE O-RINGS", "ATTACHING THE DAUGHTER CARDS TO CATHODE FRAME", and "ATTACHING THE DAUGHTER CARDS TO THE CATHODE FOIL". We decided in the latter procedures to assume using conductive tape, of course later we can modify it if it is needed. Beni will work on "SINGLE LAYER TESTING" procedure, and Lubomir on wire position and tension measurements. Depending on the needs, Lubomir and Beni will help Dave with the other procedures, as well. Dave has updated the QA plan waiting now for signatures. As for the safety documents, linked also at the review page, Bill asked about the flammability of the ethanol we want to use to clean the wireframes in the ultrasonic cleaner. Example: 40% ethanol solution with water is flammable at 26degC. Need the help of the EH&S people for that.

Electronics

- Lubomir explained the need to have testing step pulse with a variable amplitude from fADC125 fed on the pre-amps to easily check the linearity of the electronics. Gerard and Fernando are needed for this discussion.

- Beni learned that for the discriminator boards there's already a translator from LVDS to ECL used in Hall B. So the design exists and we just need to make several for our FDC package tests. Chris will discuss it with Fernando.

- Chris: all the 34 signal cables arrived and have been tested: all are OK. Another 16 will come soon. As for the tinning of the rigid-flex cotacts he wanted to know when we will decide about the technique of the soldering. Bill thinks that one can use conductive tape even with tinned contacts. To test this we will tin three flexes manually, solder them using conductive tape, and do the same tests as with the non-tinned samples that we have already.

Engineering

- Bill was working on some tooling: for sanding the outer 3mm of the Rohacell on the wire frames (ready), for the wire stringing sensors, and also on the new jig table that will be used for the package assembly. We decided that at the beginning, for the package assembly we will use the existing jig plate and the gusset from the prototype.

- So far we have 5 samples with conductive tape putting them daily in and out of the fridge. To accelerate the testing we will try some extremes: putting the samples in liquid N and also in hot water. Eugene was skeptical about the value of such tests, assuming they will not pass. Still it doesn't hurt to try it with some of the samples. Beni will contact target group to help with the liquid N.

Chamber testing

- Lubomir is analyzing the data from the scan of one half of the prototype after calibrating the strips. The relative calibration is based on the fact that the top and bottom strips see the same charge and that one top (or bottom) strip from one card "crosses" all the bottom (or top) strips from another card. After the calibration the position resolution improves by ~20%. It was found also that two strips (out of 192) are not showing signals. We are considering to open the prototype chambers soon after the review. For that we may want to use the jig plate to transport the prototype to Blue Crab where it will be opened.

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