FDC Weekly Meeting
Date: July 9, 2009
Participants: Daniel, Rich, Mark S., Simon, Bill, Beni, Mark I., Eugene
Next Meeting: July 16, 2009 @ 1:30 p.m.
General Construction Updates
- The parts for the assembly jig on which the detector stack will be constructed are in our possession. Mark S. and Brian will assemble the jig when they have time and do some test fits. - Bill will take on the preparation for a stack assembly document. A draft will be prepared before assembly of the full-scale prototype and then fleshed out during the process with relevant photographs taken. - Cable preparations: * The LV cables have arrived and will be tested in the near future. * Fernando reported that the HV cables have been made and tested. He recommends that we test them with the new CAEN HV modules as there have been some recently reported problems with this type of module here at JLab. * The signal cables and connectors are in hand and Mark and Brian will begin construction as they have time. * We still need to decide how much of the outer jacket and braid will be stripped off the signal cables. - Brian and Mark S. will begin making up the composite frames for the two gas windows. They should be ready within a couple of weeks. - Mark S. prepared the PO for the cables that will be used to attach to the cathodes for the external ground. He will also order the sealing epoxy that is used to cover the conducting epoxy. - We discussed some proposed modifications to the cathode tensioning facility that Bill would like. As it turns out that the most recent cathode that we made with weights turned out quite well (i.e. no air bubbles). In light of this, we decided not to pursue this discussion too far and to revisit it after we have made a couple of more cathodes. - The parts for the second gusset ring have been delivered.
Wire Frame Update
- Repair work on the second frame (P2) has been on hold as we lost our microscope and it has taken us some time to scramble a bit and find a suitable alternative. We are very close and Brian and Mark S. will get back on making repairs. Rich has started to look at the frame P4, which was alledgedly the worst of the frames mechanically, and he claims that it seems to have less problems than the others. Still awaiting full details. - We have found that the boards are quite dirty and have quite a bit of solder flux. We are starting to develop cleaning plans and will ensure the boards are clean before stack assembly. - We need to have a dedicated meeting to design what the schedule for work on the Phase 3 wire winding will be. The highest priority for work scheduling will be doing work on upgrades of the wire winding facility. This includes a better strongback design, the design and construction of precision combs, modification to the wire winding table, and a list of other items with the system. Stay tuned, more to come. - We are pushing hard to begin wire frame construction early next year and begin wire winding before the end of 2010. Hopefully this can all procede. We are now working to complete the simulation studies with Simon to determine if we want to offset neighboring wire layers. More to come in the upcoming months. - The wire frame construction document is located at: /u/group/halld/Engineering/PRELIMINARY DOCUMENTS. We will include the information on the wire electroplating process shortly. - Bill is now designing the jig for the wire electroplating operation and it will be ready for submission to the shop at some point in the future. We will make a decision shortly if/when we will electroplate the wires for the full-scale prototype. - Brian received the SEM scans for our wire from the W&M folks. He will generate a final QA report with photos and test results for all wires in the next several weeks.
- Progress updates: * Mark S. has completed edge sealing and gas hole inclusion and sealing in 5 of the 8 cathode frames. He is working on this as he has time. * Cathode construction progress: - All 7 cathode panels (2 5-um Cu and 5 2-um Cu) have been prepared. - 3 cathodes (1 5-um Cu and 2 2-um Cu) have been tensioned and laminated to their laminate rings. - 1 cathode (5-um Cu) is in the tensioning facility now and has been tensioned. Presently studying the tension relaxation with time before completing the lamination process. - 1 cathode (2-um Cu) has been attached to the second transfer ring and is awaiting tensioning and lamination early next week. - 2 completed cathode panels are hanging in the clean tent. * Each cathode constructed this far has some sort of problem or non-ideal feature. Mark S. is keeping track of these in our log. One of our 7 cathode panels (a 2-um Cu) has a significant amount of epoxy +/-5 inches about each panel seam and most likely will not be usable. We are looking into way to try to remove the epoxy, but it will take some chemistry. We shall see. * We have a plan in place to get the completed cathode boards back under environmental control. Hopefully this will happen next week (but of course I said this last week and the week before and the week before ...). * We have a bit of a back up doing the flatness scans of the completed cathodes. DSC will talk to Mark/David/Micah to find out where we are. * Mark S. tensioned the second 5-um cathode board this week, but he saw a 15-18% decrease the next day. We discussed how to proceed. The nominal tension on each board should be set to 500 N/m. We will allow the board to sit overnight and remeasure the tension the next day. If is is stable to within 10%, we will complete the lamination. If it is outside of this bound, we will retension and relaminate. Note that relative humidity should be recorded for each measurement. - The Fast Electronics group will complete the soldering of the rigid-flex assemblies within about 2.5 weeks. A small number will be made available on a shorter time frame for Mark S. to practice soldering them to the cathode with the epoxy on the front. Mark S. will be responsible (for now) for soldering the rigid-flex assemblies to the cathodes. - The current draft of the cathode construction document being worked on by Bill is located at /u/group/halld/Engineering/PRELIMINARY DOCUMENTS. As new pictures are taken, they are being incorporated. As procedures are modified or fine tuned, the document is being updated. - We are standing by waiting for information on the PR for the 2-um board material. - Roger needs to prepare a document for QA/stuffing/cleaning for the cathode boards and a similar document for the cathode daughter boards and ground boards.
Cooling System Tests
- Fernando is in the process of writing up the results from his cooling system studies. Stay tuned for the GlueX note. He indicated that he is back to work on this document and it should be done shortly.
Cosmic Ray Test Stand
- Beni is continuing work to setup the cosmic ray telescope and test system in EEL 126. Progress has been slow but steady with getting CODA and the DAQ working. There is still much to do, but things are coming along. In the past week, Beni has gotten a VXS VME crate from the Fast Electronics group and a 250-MHz JLab FADC. - We still have some mysterious behavior with the small-scale prototype response with wiggles in the X vs. Y distributions that need to be understood. We decided to have a separate meeting to discuss what work we would like to do on the small-scale prototype. - Beni has started a bench test plan for the full-scale prototype and is presently working on it after incorporating feedback. It was also suggested to send it to Curtis for feedback. He will post it as a GlueX-note shortly. - The machined parts for the support/rotation of the full-scale prototype in the cosmic ray stand have been delivered. We are awaiting some purchased parts to arrive. After we have everything in hand, it will be assembled and test fitted. - Safety paperwork for the cosmic ray test stand has been turned in for signatures, but the process is slow. Upon approval we will fill the chambers with gas and be able to turn on the high voltages. At present, we have decided to locate the gas bottles outside of the EEL building.
- The FDC short-term work list has been posted on the FDC web site. This is continually being updated and DSC welcomes any feedback or comments from the group.
Minutes prepared by Daniel. Send any comments or corrections along.