FDC Weekly Meeting
Date: April 23, 2009
Participants: Daniel, Beni, Brian, Mark S., Simon, Roger, Mark I., Eugene, Chuck, Bill
Next Meeting: May 7, 2009 @ 1:30 p.m. (Note: No meeting next week)
Full-Scale Prototype Updates
- Cathode Board Orders * Cathode boards: Roger has reviewed the order with the Allflex folks. We are still expecting delivery by the beginning to middle of May. Mark S. will send the transport box up to Allflex by tomorrow. Roger still has to send up a note on packing and shipping instructions. This will happen soon. The issue of board corrosions and steps to mitigate this further are being considered at the company. They will update Roger shortly. * Cathode daughter boards: Roger has received quotes and the PR is being finalized. Not much longer until this goes out. Expected turn around time is 2 weeks. - Chamber Wire: * Brian announced that the SEM studies of our wires should be complete 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: * Greg Arnold's group will not be available for our work until maybe the end of May. It looks like we can get manpower if needed through Chris Cuevas' group so that delays on the wire board Phase 2 soldering and the connection of the rigid-flex assemblies to the cathodes is not delayed. We may need to borrow the wave solder machine from Greg's group. More to come as schedules come into focus. * To avoid concerns with melting the epoxy on the cathode boards during soldering of the rigid-flex assemblies, we want to do a test to make sure that there are no problems. Mark and/or Brian will set this up. - We are now sharing the clean tent with Hall B. The Hall B folks will need about 2 to 3 weeks of time to finish their work. - Bill received an estimate to make up 22 new cooling system clamps. The price is about $100 apiece. This PR has been signed and we expect the pieces back within a couple of weeks. - We reviewed remaining tasks to complete the design of the FDC design. DSC showed a preliminary list (see FDC design task list). This needs to be looked over and fleshed out by folks. DSC reminded folks to give him feedback about this list. - Bill will put together the order for the o-ring material for the full-scale prototype.
Wire Frame Update
- Status: The linear transducer has finally been sent off for refurbishment It should be back and reinstalled in about 1 week. - As the IUCF work has been delayed, DSC has requested a no-cost extension for one month and talked to Sharon Williams. This work will be completed shortly. - 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. This is not a high-priority job at the moment. - The bearing for the rotatable platter for the Phase 2 soldering is in hand. Mark will put this jig together in the next couple of weeks. - Mark will test fit the wire frame protective cover to be sure it is idiot-proof and does the required job.
- We reviewed the cathode R&D timeline. - Progress updates: * The 8 cathode frame laminates and G10 annuli have been given over to the JLab machine shop. It will be decided in the next day or two whether the work is done in house or on the outside. The job will then take two weeks to complete. * 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 have been handed over to the machine shop. * To deal with issues of epoxy seepage through our Kapton tape, we have done a test of a modified procedure where we first put removable tape on the copper side of the boards. After applying the Kapton tape to the back of the boards and allowing for it to cure, the tape on the front side is removed. This worked very well and we will do a few more test with some dummy boards before laying up the last 2 micron Cu board set. For this work, we cannot float the boards in alcohol as it desolves the glue on the removable tape. Water has been shown to work as a reasonable alternative. Trying to lay the cathode panels up without water or alcohol does not work as the ends of the boards tend to curl up. * Some progress on the mechanical prototype. The power connectors have been soldered to the rigid-flex assemblies and the preamp card connectors have been added to the wire frame. Next week this system will be put together for design checks. This will include the cooling lines for the preamp cards. * Bill has been working on the cathode construction document. He will circulate a draft shortly.
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 will want to scan our 5 micron Cu cathode and then to scan our 2 micron Cu cathode once we have a frame to mount it to. This is important input on the minimum tension values. The 5 micron Cu board is ready for scanning and the 2 micron Cu board will have to wait until we have a frame to mount it to.
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. - 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.
Cosmic Ray Test Stand
- We will be moving the FDC cosmic ray test stand from the Test Lab back to the EEL building. Beni has come up with plans for the room layout in EEL 126. We will be working to remove the big storage shelf system to clear up space and try to get this out of the room in the next 2 to 3 weeks. - 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.