Difference between revisions of "Minutes-5-12-2011"

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# Production
 
# Production
#* Status (Dave)
+
#* Status and plans (Dave)
 
#* Wire tension scan [http://www.jlab.org/htbin/PHYSICS/halld/enote112.pl?nb=notebook&action=view&page=565 logbook page 565] (Lubomir)
 
#* Wire tension scan [http://www.jlab.org/htbin/PHYSICS/halld/enote112.pl?nb=notebook&action=view&page=565 logbook page 565] (Lubomir)
 
# Engineering (Bill)
 
# Engineering (Bill)
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#* Other
 
#* Other
 
# Electronics (Fernando, Chris)  
 
# Electronics (Fernando, Chris)  
#* Status
 
 
#* Rigid-flex stuffing
 
#* Rigid-flex stuffing
 +
#* Other
 
# Chamber testing (Beni, Lubomir)
 
# Chamber testing (Beni, Lubomir)
 +
#* Gas system at Blue Crab
 
#* [http://www.jlab.org/Hall-D/detector/fdc/production/equipment_bluecrab.txt Equipment for Blue Crab]
 
#* [http://www.jlab.org/Hall-D/detector/fdc/production/equipment_bluecrab.txt Equipment for Blue Crab]
 
# Other
 
# Other
  
<!--
 
  
 
= Minutes =
 
= Minutes =
  
Participants: Eugene, Bill, Dave, Roger, Beni, and Lubomir.
+
Participants: Eugene, Bill, Dave, Chris, Simon, Beni, and Lubomir.
  
 
== Production ==
 
== Production ==
  
- Dave: Two cathode frames type 3 (with ground planes with holes) are assembled waiting for the rigid-flexes and ground wires to be glued on them. One wire frame was strung, the wires glued and now being soldered. Expect to be ready by the end of the day, then we will do position and tension measurements. We started also cutting foils for the third cathode plane and the second wire frame is also ready.
+
- Dave: The first two cathodes are assembled waiting for the rigid flexes. Anatoly is cuting the wires on the first wire plane right now. The third cathode is tensioned and the frame glued; next is to tension and glue the ground plane. Fourth cathode is ready to be tensioned. The ultrasonic cleaner is back and Al is installing it now. We will fill it with distilled water. The frame will be cleaned first with Vigon and then put in the ultrasonic cleaner. We are waiting for the tool ring needed to tension the end windows.
  
- We discussed the configuration needed to test the first chamber: end window, cathode type 3, wire plane, cathode type 3, end window, plus empty frames to make the same thickness as of the full package. We will use the plastic gussets. Bill wanted first to do gas leakage tests with these plastic gussets, but actually such test was done before.  
+
- Final results from the position and tension measurements of the first production chamber are shown at page 565 of the FDC logbook. We decided that we have to fix the offset in the pin position of the jig rail. From the position measurements (as explained at page 565) the pitch is short by ~130 microns. Dave measured it directly with a caliper and found ~100microns which is consistent, given the precision of the caliper and the fact that 130microns is the gap averaged over all the wires on both sides. Bill will bring the pin rail to the machine shop for fixing it and will try to expedite this since it stops the wire plane production. His idea is to increase the hole sizes so that one can vary the gap, to map the positions of all the pins and thus to adjust the gap, after that to put pins to fix the position. Tension measurements were done in a half a day, the voltage on the generator was kept 1V for both field and sense wires (before we used 3V for the sense wires). We found one sense wire broken between the solder pad and the glue; it was replaced by Casey. One of the filed wires had lower tension because of its weight touching the lower plate of the weight shielding. This most likely happened because the screw used to attach to the wire was not so tight and the weight slipped. Adding to the procedures: before gluing the wires one should open the shielding and check that all the weights are hanging.
  
- End window material. Bill found two options: 1mil available now, and 2mil roll for ~$1500 total that we can have in ~2 weeks. For the first two end windows we decided to use the 1mil material.
+
== Engineering ==
  
- Wire position measurements. We had problems finding the field wire positions: the laser sensor doesn't see about 20% of them while sees all the sense wires. Possible explanations: vibrations due to HVAC on the top of the clean room; one can actually see the weights vibrating. It could be also the surface of the field wires is somehow different in reflecting the laser beam. Before for the test wire frame all the field wires were seen by the sensor, but we used different type of field wires. Two samples of our field wires will be analyzed with electron microscope by Olga. It turned out that if the sensor doesn't see the wire, a tiny move along the wire is enough to see it. This is the way all the wires of the first chamber were scanned before gluing them. These results are compared with the old results for the test chamber at page 564 of the logbook linked above. In between the two stringing the jig rail was modified to fix the ~250microns offset in one pitch, but now it looks like we have ~80 microns in the opposite direction. Eugene also mentioned the difference in the slope in the above plots before and after for which we couldn't find an explanation.  
+
- Bill: problem with one machine at "Vision Machine" and that's why we are still waiting for the ring needed to tension the end windows and for the jig plate needed for the chamber assembly. Hopefully we will have these at the beginning of next week. The parts for the ultrasonic cleaner and the tool to tape the wires (with Kapton dots) are in the machine shop. Finally we have the four penetrations in the clean room done. We don't have to vent the gas out of the clean room, so the bubbler for the tests will be inside.
  
- We were able to fix all the sense wires that were off by more than ~60 microns (6 wires in total) by re-taping them. Also right after gluing we scanned all the sense wires. It took ~1 hour and in principle you could correct the wire positions if you have to, since the glue is still not hard enough.
+
- Tools and parts needed for the package assembly (and also for the first chamber testing): Bill prefers to have one gusset for one side of the package instead of many sectors, though it will be more expensive. The tooling will be similar to the one we used for the full-scale prototype, some parts (like the hubs) are now on the prototype, but Bill will make a second set so that one can be used for testing and the other for assembly. For the first chamber tests we will take the parts from the full-scale prototype. Eugene suggested not to disassemble the prototype so that we can do comparative tests if we have to. Therefore we will take only the hubs and replace the gussets with plastic ones.
 +
 
 +
- After the meeting Bill, Dave and Lubomir went to 126 to discuss the procedure for the partial disassembling of the prototype. We decided that the best is to transport the prototype to Blue Crab and replace some of the parts needed for the first chamber assembly and testing. Such replacement will be done sector by sector so the prototype will be affected minimally. We need to take the hubs and some of the rods. This will happen beginning of the next week and we better use a van in which we put the chamber horizontally on a flat Lexan plate.
  
 
== Electronics ==
 
== Electronics ==
  
- Lubomir talked to Fernando about assembling by Chris the rigid-flexes that are needed for the first chamber. If we can have the assembled flexes back from the company within a week that would be fine, but if not we should consider doing it here. We should decide about this by next Monday. Also there was a question to Fernando: what kind of tests have to be done with the assembled rigid-flexes before gluing them to the cathodes.
+
- Chris: hopefully we will have the first 100 rigid-flexes populated at the end of the next week. Then we need another week for gluing them and then one more week for assembling the chamber and setting up the tests. We decided we couldn't delay the tests that much and we need to populate 18 rigid-flexes manually. Lubomir already discussed with Fernando a week ago if Chris can do this for us.
  
- Roger brought the second batch of the rigid-flexes, to be moved to 117.
+
- Chris: the last 16 (of the first 50) signal cables have arrived and tested, they are OK.
 
+
== Engineering ==
+
 
+
- Bill: the ultrasonic cleaner that was fixed by the manufacturer will be back next week. Bill was looking also for a storage for the produced chambers.
+
  
 
== Chamber testing ==
 
== Chamber testing ==
  
- The parts needed for the chamber testing at Blue Crab are listed above by Beni. Mark will help him with the gas connectors. We have now only one Bertan supply that we have to share between 126 and Blue Crab. The second supply has to be fixed but they asked for $1700 just to look at it; Mark will try to fix it. We need also blind penetration in the clean room walls to have gas inside. Eugene will try to expedite the work order made weeks ago.
+
- For the gas system Beni wanted to have the right connectors instead of using putty at several places. Bill will order these (not from Lowes).  
 
+
- Beni connected a pressure sensor to measure the pressure difference between the top and middle chamber of the prototype package, but the readings fluctuate because of the bubbling. The best is to connect the sensor to the extra tubes on the spacer rings, but those are broken and the fix them most likely will require disassembly of that package.
+
  
-->
+
- Lubomir: the first chamber (as well as the packages later) will be tested in 126 in two positions: vertical, for gas leakage and with a source, and horizontal, with cosmics. For the horizontal position we will use additional plates/frames as with the full-scale prototype to make the construction stiffer. For the first chamber we will take these parts from the full scale prototype.

Latest revision as of 09:27, 13 May 2011

May 12, 2011 FDC meeting

Agenda

  1. Production
  2. Engineering (Bill)
    • Tooling
    • Package assembly design
    • Other
  3. Electronics (Fernando, Chris)
    • Rigid-flex stuffing
    • Other
  4. Chamber testing (Beni, Lubomir)
  5. Other


Minutes

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

Production

- Dave: The first two cathodes are assembled waiting for the rigid flexes. Anatoly is cuting the wires on the first wire plane right now. The third cathode is tensioned and the frame glued; next is to tension and glue the ground plane. Fourth cathode is ready to be tensioned. The ultrasonic cleaner is back and Al is installing it now. We will fill it with distilled water. The frame will be cleaned first with Vigon and then put in the ultrasonic cleaner. We are waiting for the tool ring needed to tension the end windows.

- Final results from the position and tension measurements of the first production chamber are shown at page 565 of the FDC logbook. We decided that we have to fix the offset in the pin position of the jig rail. From the position measurements (as explained at page 565) the pitch is short by ~130 microns. Dave measured it directly with a caliper and found ~100microns which is consistent, given the precision of the caliper and the fact that 130microns is the gap averaged over all the wires on both sides. Bill will bring the pin rail to the machine shop for fixing it and will try to expedite this since it stops the wire plane production. His idea is to increase the hole sizes so that one can vary the gap, to map the positions of all the pins and thus to adjust the gap, after that to put pins to fix the position. Tension measurements were done in a half a day, the voltage on the generator was kept 1V for both field and sense wires (before we used 3V for the sense wires). We found one sense wire broken between the solder pad and the glue; it was replaced by Casey. One of the filed wires had lower tension because of its weight touching the lower plate of the weight shielding. This most likely happened because the screw used to attach to the wire was not so tight and the weight slipped. Adding to the procedures: before gluing the wires one should open the shielding and check that all the weights are hanging.

Engineering

- Bill: problem with one machine at "Vision Machine" and that's why we are still waiting for the ring needed to tension the end windows and for the jig plate needed for the chamber assembly. Hopefully we will have these at the beginning of next week. The parts for the ultrasonic cleaner and the tool to tape the wires (with Kapton dots) are in the machine shop. Finally we have the four penetrations in the clean room done. We don't have to vent the gas out of the clean room, so the bubbler for the tests will be inside.

- Tools and parts needed for the package assembly (and also for the first chamber testing): Bill prefers to have one gusset for one side of the package instead of many sectors, though it will be more expensive. The tooling will be similar to the one we used for the full-scale prototype, some parts (like the hubs) are now on the prototype, but Bill will make a second set so that one can be used for testing and the other for assembly. For the first chamber tests we will take the parts from the full-scale prototype. Eugene suggested not to disassemble the prototype so that we can do comparative tests if we have to. Therefore we will take only the hubs and replace the gussets with plastic ones.

- After the meeting Bill, Dave and Lubomir went to 126 to discuss the procedure for the partial disassembling of the prototype. We decided that the best is to transport the prototype to Blue Crab and replace some of the parts needed for the first chamber assembly and testing. Such replacement will be done sector by sector so the prototype will be affected minimally. We need to take the hubs and some of the rods. This will happen beginning of the next week and we better use a van in which we put the chamber horizontally on a flat Lexan plate.

Electronics

- Chris: hopefully we will have the first 100 rigid-flexes populated at the end of the next week. Then we need another week for gluing them and then one more week for assembling the chamber and setting up the tests. We decided we couldn't delay the tests that much and we need to populate 18 rigid-flexes manually. Lubomir already discussed with Fernando a week ago if Chris can do this for us.

- Chris: the last 16 (of the first 50) signal cables have arrived and tested, they are OK.

Chamber testing

- For the gas system Beni wanted to have the right connectors instead of using putty at several places. Bill will order these (not from Lowes).

- Lubomir: the first chamber (as well as the packages later) will be tested in 126 in two positions: vertical, for gas leakage and with a source, and horizontal, with cosmics. For the horizontal position we will use additional plates/frames as with the full-scale prototype to make the construction stiffer. For the first chamber we will take these parts from the full scale prototype.