Difference between revisions of "Minutes-4-21-2011"

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# Other
 
# Other
  
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= Minutes =
 
= Minutes =
  
Participants: Eugene, Dave, Chris, Simon, Beni, Glenn, and Lubomir.
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Participants: Eugene, Dave, Chris, Simon, Beni, Glenn, and Lubomir. Relatively short meeting.
  
 
== Production ==
 
== Production ==
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- we found discoloration spots on the first cathodes that were produced at Blue Crab. The spots are brown but have blue color at the periphery. There's one spot covering several thin traces close to a connector. Eugene explained the finding done with electron microscope by Olga: chlorine was found, so most likely this is copper chloride (brown) and copper chloride dihydrate (blue). We suspect chlorine is left from the etching procedure (have to verify that Allflex uses ferric chloride for etching). Then the effects we see is due to the wetting of the foils, this is needed for the alignment and gluing the panels together. So far we exclude the possibility that the copper reacts with the new packing paper. This is due the fact that we see more spots on the first article foils than on the production foils. Still, we are waiting to hear from Andy Wu who will do independent analyses. Eugene, Lubomir and others agreed that Allflex should continue with the foil production.  
 
- we found discoloration spots on the first cathodes that were produced at Blue Crab. The spots are brown but have blue color at the periphery. There's one spot covering several thin traces close to a connector. Eugene explained the finding done with electron microscope by Olga: chlorine was found, so most likely this is copper chloride (brown) and copper chloride dihydrate (blue). We suspect chlorine is left from the etching procedure (have to verify that Allflex uses ferric chloride for etching). Then the effects we see is due to the wetting of the foils, this is needed for the alignment and gluing the panels together. So far we exclude the possibility that the copper reacts with the new packing paper. This is due the fact that we see more spots on the first article foils than on the production foils. Still, we are waiting to hear from Andy Wu who will do independent analyses. Eugene, Lubomir and others agreed that Allflex should continue with the foil production.  
  
-   
+
- Dave: many problems this week. Still waiting for some signatures on some of the procedures. Yesterday there was a problem with the AC (due to transformer problem, second of this type) in the clean room; the humidity went up to 70%. It was fixed but Ron Bartek suspects a problem in the design. The power went out this morning, maybe related to Surry power plant shut down. It turned out according to Rusty Sprouse, we can't use the temporary light that we have outside of the clean room. The heater in the ultrasonic cleaner doesn't turn off; the ultrasonic cleaner was shipped back to the manufacturer for repair.
  
- the first production cathode was glued tensioned and the frame was glued to it; cutting the flaps and the holes is next. Some ofhese procedures still require signatures. Cutting the second production cathode started with problems with the cutter. Bill thinks it is the granite surface that damages the blades. Using harder blade and treating the granite surface must help. Bill also made modifications to the cutter to prevent wobbling of the blade.
+
- The granite plate used for cathode flatness measurements was successfully moved to Blue Crab. Eugene suggested to check the flatness of at least one cathode, but it doesn't have to be the first one. We will do it later; don't want to spread our efforts to many projects when we are late with the first production chamber.  
  
- a PCB ring was glued to be used for the first production wire frame. Tests with light show the surface at the seams is not perfectly flat. Anatoly will work on this. Next steps: trimming the Rohacell OD on the wire frame and laminating the PCB ring. We will accelerate this so that we can work on the wire frame in parallel with the cathodes. Bill asked if it will be acceptable to use parafin to cover some parts of the Rohacell OD that is needed for the ultrasonic cleaning. Lubomir will investigate this.
+
- After several improvements in the cutter (stronger blade and very importantly cutting on wet plastic tape as proposed by Anatoly) it's not wobbling now. Second cathode foil was glued. Second PCB ring was glued. As of now, the highest priority is the wire frame lamination, so that we can continue with the stringing. Then, in parallel we will work also on the cathodes.   
 
+
- Dave is working on the paperwork for making holes in the clean room. We decided to have 4 holes: two in the cathode area and one in each of the small rooms. The holes will be used for nitrogen, compressed air and chamber gas mixture supply.
+
   
+
- We received the solder wire (0.65mm) from UVA that we will use for wire soldering at the beginning. Al has progress with the software (for the Parker controller) used to find the wire position.
+
  
 
== Electronics ==
 
== Electronics ==
  
- Chris: nothing new, waiting for quotation for the rigid-flex tinning.
+
- Chris: discussing the price and details for the additional tinning of 50 rigid flexes, out of 100.  
 
+
- Yesterday at the tracking meeting we discussed possible modifications for the fADC125: increase of the gain to cover the whole 12 bit range that was requested by the CDC people. This is not acceptable for the FDC and as seen in the document linked above we are happy with the current version. Eugene insisted that we don't want to have two fADC125 versions which will delay their production and increase the costs, and that this will not solve the problem with the dynamic range. Now they are considering modification of the termination of the CDC pre-amps. In any case for us the fADC125 will not change.
+
 
   
 
   
 
== Engineering ==
 
== Engineering ==
 +
 +
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- Bill is working on the package assembly jig plate and placed orders for: the new 3M tape gluing tool, cutter modifications, and spacer ring needed for the end window gluing.  
 
- Bill is working on the package assembly jig plate and placed orders for: the new 3M tape gluing tool, cutter modifications, and spacer ring needed for the end window gluing.  

Revision as of 16:23, 21 April 2011

April 21, 2011 FDC meeting

Agenda

  1. Production (Dave)
    • Cathode production, copper discoloration
    • Wire plane production
    • Other issues
  2. Electronics status (Fernando,Chris)
  3. Engineering status (Bill)
  4. Chamber testing (Lubomir)
  5. Other


Minutes

Participants: Eugene, Dave, Chris, Simon, Beni, Glenn, and Lubomir. Relatively short meeting.

Production

- we found discoloration spots on the first cathodes that were produced at Blue Crab. The spots are brown but have blue color at the periphery. There's one spot covering several thin traces close to a connector. Eugene explained the finding done with electron microscope by Olga: chlorine was found, so most likely this is copper chloride (brown) and copper chloride dihydrate (blue). We suspect chlorine is left from the etching procedure (have to verify that Allflex uses ferric chloride for etching). Then the effects we see is due to the wetting of the foils, this is needed for the alignment and gluing the panels together. So far we exclude the possibility that the copper reacts with the new packing paper. This is due the fact that we see more spots on the first article foils than on the production foils. Still, we are waiting to hear from Andy Wu who will do independent analyses. Eugene, Lubomir and others agreed that Allflex should continue with the foil production.

- Dave: many problems this week. Still waiting for some signatures on some of the procedures. Yesterday there was a problem with the AC (due to transformer problem, second of this type) in the clean room; the humidity went up to 70%. It was fixed but Ron Bartek suspects a problem in the design. The power went out this morning, maybe related to Surry power plant shut down. It turned out according to Rusty Sprouse, we can't use the temporary light that we have outside of the clean room. The heater in the ultrasonic cleaner doesn't turn off; the ultrasonic cleaner was shipped back to the manufacturer for repair.

- The granite plate used for cathode flatness measurements was successfully moved to Blue Crab. Eugene suggested to check the flatness of at least one cathode, but it doesn't have to be the first one. We will do it later; don't want to spread our efforts to many projects when we are late with the first production chamber.

- After several improvements in the cutter (stronger blade and very importantly cutting on wet plastic tape as proposed by Anatoly) it's not wobbling now. Second cathode foil was glued. Second PCB ring was glued. As of now, the highest priority is the wire frame lamination, so that we can continue with the stringing. Then, in parallel we will work also on the cathodes.

Electronics

- Chris: discussing the price and details for the additional tinning of 50 rigid flexes, out of 100.

Engineering