From GlueXWiki
Jump to: navigation, search

March 24, 2011 FDC meeting


  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


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


- 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.


- 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.


- 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.