FDC Weekly Meeting
Date: December 18, 2008
Participants: Daniel, Simon, Mark S., Brian, Roger, Mark I., Beni, Chuck, Elke, Herun, Bill, David, Eugene
Next Meeting: January 8, 2009 @ 1:30 p.m.
Full-Scale Prototype Updates
- Procurements: * Rigid-flex assemblies: * The PR has been given to Elke and was signed as of today. The parts should arrive by roughly the middle of January. * The boards will be given a cursory QA checkout upon arrival and then be test fitted into the cathode frames. Upon successful tests, the remainder of the order will go out. * G10 ring order status: * The order has arrived and has been placed on the shelves in EEL 126. * 110IG Rohacell order status: * Bill contacted the company and the order was delayed. It will arrive at JLab this year, but after the start of break. Mark or Brian will talk to shipping and receiving to find out what will happen if the order arrives during break. * Wire QA studies: * The QA checks for the sense wires are complete. * The W&M folks have not yet gotten started on the field wire tests. * DSC will send Brian info on the SEM studies of the Hall B CuBe wire. * Brian will prepare a final QA report with photos and test results for all wires when all studies are complete. - Mark S. is also responsible for upkeep of the list of procurements for the full-scale prototypes. * Location: M Drive/halld/Electronics, or for more sophisticated folks, /u/group/halld/Electronics. - Bill is working to put the local HV connectors selected by Fernando into the 3D CAD model and to detail how they will be attached (as they are quite massive). Bill will get back to this work when he has a chance.
Wire Frame Construction
- An updated draft of the wire frame assembly document has been prepared and is ready for review: Wire frame assembly document. All comments should go to Bill as he works to prepare a modified draft. DSC provided Bill with comments. All FDC procedure documents should ultimately find their way to the GlueX portal. - See the FDC wire frame specification/tolerance document. - The JLab machine shop has completed additional machining work on the vacuum bagging jig. It should now be back in our possession. - Brian and Mark will work to complete a humidity test of our G10/foam laminate in a dry box. This work should be completed soon so that the vacuum bagging steps can be finalized in the procedures document. - The templates for cutting the foam core pieces have gone out to be anodized to improve surface hardness. They will be back shortly. - Elke has officially notified IUCF of our window for arrival of the four wire frames. The window is the last two weeks of January 2009. Brian indicated that Casy has a job coming into the shop in the third week of January that will need the horizontal mill. Thus we have to be done with all machine shop work for the wire frames by then. - Kim needs to complete the PCB stuffing/cleaning document. This should be done by the middle of February.
- We reviewed the cathode R&D timeline. Folks are reminded to pass on progress updates to Chuck every Wednesday. The current schedule is being kept on the mdrive at: * Location: M:\halld\Individual-Schedules\FDC or for more sophisticated folks, /u/group/halld/Individual-Schedules/FDC * A couple of problems were repaired in the official schedule and a few tasks clarified and added. Please refer to the latest version for reporting. Talk to DSC or Chuck if you have any questions. - See the FDC cathode frame specification/tolerance document. - Mark has been assembling portions of the edge cutting system. A series of parts n' pieces are now being machined at FSU and will be sent to JLab this year. After assembly of the system, we will work through a full test plan before cutting any of our "real" cathodes. - Due to other priorities, the construction document for the cathode frames and cathode sandwiches has not gotten very far. We should plan to have a draft of this document available before the onset of construction of the first 5-micron Cu board in the second half of January. - The cathode R&D plan in the first part of January will focus on construction of a full cathode sandwich. This will include ground connections to the cathode foils and ground connections to the ground plane. After this work is done, we can proceed on the 5-micron Cu cathode (presuming the edge cutter is up and ready to go). - Minor design issues with the cathode tensioning system are being addressed with some work done by the machine shop. The pieces are now done in the shop and are awaiting pickup. - We focussed on the attachment of Roger's rigid-flex assembly to the cathode frame. Bill was worried about the difficulties of having a cut-out on the G10 skin and tolerance issues with attaching the Cu fingers on this board with the cathode board solder pads. We have decided to do away with the cut out and epoxy Roger's boards to the G10 frame. If this proves problematic, we will revisit the issue later. - The first attempt at using the mini-tensioner with a sample of our 2-micron Cu board failed as the system only had four tensioning screws. This did not allow a uniform tension to be set. The machine shop added 4 additional screws to the system. Brian prepared a blank Kapton piece and Eugene set and measured the tension. He was satisfied that the system is ready for the ready cathode board material. Brian and Eugene should complete the distortion measurements this week using a tension of 400 N/m. - We discussed the limitations of our current cathode tensioning system. The best way to try to set a uniform tension is to use a torque wrench on all bolts. We will try to make due with this system as it is for the full-scale prototype cathodes. We have a preliminary design from Bill to upgrade this will air cylinders and springs, but that will wait for now. - Mark performed some handling tests on the 2-micron board that involved lifting with a suctioning system. We decided ultimately to go with a lower-tech solution. This will be developed and tested in January 2009. More to come. - We discussed a bit more the connection of external grounds to the cathode boards and the ground plane. Bill believes the best approach is to leave additional material at half a dozen places on the O.D. and to secure these pieces for connections like he has designed already. More to come.
Cathode flatness measuring system
- Micah completed additional scans of the high-tension cathode board (600 N/m version) and the granite table. See his slides for more details. - Micah has begun the transfer of knowledge on cathode flatness scanning to Mark S. Mark S. demonstrated his expert status by performing several scans himself. More training to be done to let Mark know how to analyze the scan data. - Documentation of the system continues. See the FDC wiki wiki page for details.
- Mark has done some tests of attaching Kapton gas inlets and outlets into the holes on a prototype spacer frame using an injection molding process. He believes that he has worked the kinks out. We want to check to make sure the instant adhesive employed will be chamber safe. - The first two frames will go to the shop shortly and Bill will order the remaining stock needed.
Stack Assembly Procedures
- DSC, Brian, and Bill will work to finalize the stack assembly construction document that has been prepared. This document should be in place before we get too far in the construction process. - Bill has found some plastic threaded rods that could be used to compress the stack. We will be receiving some samples shortly and will carry out some loading tests.
Cooling System Tests
- Fernando is in the process of writing up the results from his cooling system studies. Stay tuned for the GlueX note. - Bill has done some ANSYS modeling to better study the connector that goes from the daughter board card to the cooling loop. These will be added to Fernando's note.
- 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.
- We will be moving the FDC cosmic ray test stand from the Test Lab back to the EEL building. This move should be completed in the next 6 months or so.
- 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.