FDC Weekly Meeting
Date: May 14, 2009
Participants: Daniel, Mark S., Simon, Mark I., Fernando
Next Meeting: May 21, 2009 @ 1:30 p.m.
Full-Scale Prototype Updates
- Cathode Board Orders * Cathode boards: The cathode boards are being prepared this week and should be here at JLab by May 18 or so. Allflex is still considering the procedure of adding a second rinse stage to clear off developer and other potential corrosive chemicals. Roger is awaiting word. Roger has prepared a draft of the shipping requirements and will pass this on to Allflex. * Rigid-flex assemblies: The order for the rigid-flex assemblies (readout + ground boards) is out. Roger has ordered 60 of each type. Delivery expected within about a week. - Chamber Wire: * The SEM studies of our wires should be completed very shortly. This includes a check of the ovality of our sense wire and the mass spectroscopy reports. Stay tuned. Brian will prepare a final QA report with photos and test results for all wires when all studies are complete. - Soldering Work: * Fernando's group will handle the Phase 2 soldering work for the wire frame boards. This work should be able to begin on May 22 if Mark S. gets back from IUCF on schedule. DSC has contacted Kim to see if we can get the soldering equipment from Greg Arnold for this work. * DSC contacted Kim to set up Greg's group to do the soldering for the rigid-flex assemblies (preamp connectors + addressing resistors) in early June. The cathode soldering work should be ready to proceed by the third week of June. * To avoid concerns with melting the epoxy on the cathode boards during soldering of the rigid-flex assemblies, a test was carried out. There were no problems whatsoever mechanically. The issue was the lack of control of the height of the solder joint. This needs to be looked into to develop better controls. * Fernando was asked to finalize the component values for the preamp card addressing resistors for the wire frames and cathode frames. This work is in progress. - We are sharing the clean tent with Hall B. The Hall B folks will need about 2 to 3 weeks of time to finish their work. We need to work out a reasonable schedule for our work in the clean tent to be sure that we have no conflicts with FDC work. - The cooling clamp assemblies for the preamp boards are in our possession. There are enough pieces for the full-scale prototype. Note that there are several different types of these assemblies to allow mating with the cooling ring loop. This was news to some of us, but at least now we know! - Bill will put together the order for the o-ring material for the full-scale prototype. We will also make sure that we have enough of the epoxies, syringes, and applicator tips that we nominally use. - We need to make sure that we have the support rods that go through the full-scale prototype on hand. DSC will follow up on this. Also we need to make sure that we have the appropriate pins for the construction jig. - We will use 5 existing 5-mm thick G10 rings for supporting our cathodes in a flat position after construction. - Fernando reported that the HV cable has been received and we are now waiting on the connectors. The signal cable and connectors are in hand are Mark S. will make the signal cables for the FDC and CDC prototypes. Kim is ordering the LV cables.
Wire Frame Update
- Status: IUCF is working to wind the fourth frame. They thought that there was a problem with the tensions of the wires on the table as they had sat for about 1.5 months. The table was cleaned off and then they found that there was a mistake in their calculations. They wound the table with the remaining sense wire and field wire and it was not enough for a full plane (84 sense wires instead of 96). They will use wire on both sides of the table and be able to wind the full plane. The wire soldering will be done by early Tuesday and measurements of position and tension will follow on Tuesday and Wednesday. - Mark S. will drive out to IUCF next Wednesday and pick up the frames on Thursday. - The systematic problems with wire placement on the first three frames have been linked to systematic problems with the Moire mask. IUCF did optical measurements and sent us a report. For the fourth plane, we will position the wires using a 30-cm length of the Moire mask that is in reasonable shape. - IUCF is now working on the budget for Phase 3 (production winding). This will be delivered to JLab by the end of May (the end of the contract). - Bill will send Keith some information on which sections of the wire winding procedures document needs input from them to filling in holes. The start of this procedures document is included in Bill's IUCF trip report (GlueX-doc-1229). - Bill has been updating the wire frame construction document based on lessons learned from the prototype frames. The newest version is located at /u/group/halld/Engineering/PRELIMINARY DOCUMENTS. Please read it over and give him feedback. - Brian will gather all the bits n' pieces for a write-up on the wire electroplating and post his document on the mdrive for feedback. - 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. He will get back to this work after the tagger review is done. - Mark and Brian completed work on the turntable for the soldering techs. This system has a magnifier mounted across it. Protective covers for the wires are nearly done. - Mark found that our the rigid-flex assembly solder clearance slots on the back of the fifth wire frame that we have (with the solder mask boards) had very noticeable non-uniformities in the depths of the slots. Some problem from machining. DSC asked Keith at IUCF to check the slots on the frames that he has. If the problems are there too, we will have to do something about this. Bill is aware of the problem and will think of a solution (after the Tagger review). - We are starting to consider moving up production winding to the end of next year. DSC and Eugene are now in discussions. - Eugene will look into the state of the agreement with Hampton University for FDC construction in their clean rooms. The loop on this needs to be closed soon.
- Progress updates: * The 8 cathode frame laminates and G10 annuli will be done in the machine shop on May 21. * Other JLab machine shop work: The aluminum clamp ring for the tensioning facility will have its I.D. increased to give better access; One of the G10 tensioning rings will have its I.D. increased and will get a skim cut to remove old glue and Kapton; the thin G10 rings that make up the remainder of the cathode frame laminates will have all the through-holes and gas holes added. These pieces will also be done on May 21. * Bill has been working on the cathode construction document. He will circulate a draft shortly. He has been tied up with the tagger review. - The cathode cutter is ready for action once the cathode boards arrive from Allflex. - The company that makes our 2 micron Cu board material will end production of this line in the next few months. We are looking into purchasing the amount needed (~1500 ft) for the full production run of the boards. The raw material will be stored in an inert environment until needed for construction. Roger is getting an estimate now for the material. - As the rigid-flex assemblies will be soldered onto the cathodes directly over a region where the Kapton is laminated to the G10 skin, we were worried about delamination that could occur due to the heat from the solder gun. A test was done and a rigid-flex assembly was soldered onto a test piece. Robustness/destructive tests are still planned as part of this work. - Additional space on the walls of EEL 126 has been set up for storage of our completed cathodes. - 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.
Cathode Flatness Measuring System
- Documentation of the system continues. See the FDC wiki page for details. - In order to make decisions on the tension settings for the cathode planes, we want to understand the surface flatness. We have scanned the flatness of our 5 micron Cu cathode and are going through the data now. We will also scan our 2 micron Cu cathode once we have a frame to mount it to. This is important input on the minimum tension values.
Stack Assembly Procedures
- Brian agreed to start a draft of the stack assembly document. This document should be in place before we get too far in the construction process. - Bill has some design work to do to finalize the plans for stack compression. He is starting to think about this more.
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
- We will be moving the FDC cosmic ray test stand from the Test Lab back to the EEL building early next week. Beni has come up with plans for the room layout in EEL 126. The room has been prepared for the move. - 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 we discussed his preliminary document briefly. He will circulate it for feedback and we will continue to flesh it out. We want to make sure that we do some checks of gas leakage with the prototype. We agreed that the best procedure would be to use the P5 gas mixture (non-flammable). Bill and/or Brian will start to think about designing a system to rotate the prototype from vertical to horizontal. - For the full-scale prototype tests, we will have roughly 30 preamp boards stuffed (to be shared among everyone), 3 125 MHz FADCs, and "plenty" of TDCs. We need to flesh out a plan for who gets what and when. Beni is starting to work on this. - We discussed the thoughts regarding a beam test for the full-scale prototype. It looks like there may not be enough time and readout, but no final decision has been made. For now, we are pursuing what we can learn with cosmics and sources.
- 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.