FDC Weekly Meeting
Date: April 9, 2009
Participants: Daniel, Beni, Brian, Mark S., Simon, Roger, Mark I., Eugene, Fernando
Next Meeting: April 16, 2009 @ 1:30 p.m.
Full-Scale Prototype Updates
- Cathode Board Orders * Cathode boards: The PR has been signed and is in the JLab Procurement Office. Bill provided Roger a final list of changes to the boards that will be incorporated. Roger has sent these on to Allflex and is awaiting feedback. Roger will finalize with the sales representative the final rinsing procedure. We will also send Allflex our transport box shortly. Delivery is being specified as 6 weeks, but the Allflex representative believes it should actually be closer to the first week of May. The final order will have 7 sets of 2 micron Cu boards and 1 set of 5 micron Cu boards. * Cathode daughter boards: the PR is essentially ready and will go out shortly. Turn around for the order will be less than 2 weeks. - Chamber Wire: * We are waiting for the W&M SEM folks to finish training their folks on the new SEM and then they will finish our wire QA checkout. 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 the middle of May. This will probably be O.K.. We need to make sure that this work is planned and coordinated.
Wire Frame Update
- Status: The linear transducer has finally been sent off for refurbishment It should be back and reinstalled in about 2 weeks. - Folks who have not read Bill's IUCF trip report (GlueX -doc-1229) should look it over and provide feedback. - Bill has been updating the wire frame construction document based on lessons learned from the prototype frames. He is working to incorporate some more relevant photographs. The newest version is located at /u/group/halld/Engineering/PRELIMINARY DOCUMENTS. - 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. Bill will complete the design and get the drawings to the shop shortly. - 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. 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 - Progress updates: * Frame construction has now begun in earnest and should be done by the end of next week. All Rohacell pieces have been cut and 3 foam annuli have been put together. One G10/foam laminate has been made. Bill will communicate all details to Eugene so that we can arrange to have the machine shop work done by the second week of May. We plan on making up 8 cathode frames. * The second 5 micron Cu board was attached to our last complete support frame and is stored flat in the Lucite box. This board may be used in the full-scale prototype. * The first 2 micron Cu board was laid up. There were some issues with epoxy seepage onto the face of the boards. We discussed an alternative procedure to eliminate this problem and it will be tried out on the next 2 micron Cu board. * The 2 micron Cu board was put into the tensioner for Eugene to work on. The cathode was stretched to 450 N/m. The same pressure by the springs produced 650 N/m for the 5 micron Cu cathodes. There is a "gradient" along the strips 370-500 N/m, see sample 9 in http://www.jlab.org/~gen/gluex/Foil-tension-2.xhtml. * Due to work on other things, the attachment of the rigid-flex assemblies to the cathode sandwich mechanical prototype has not been completed yet. We discussed again what needs to be done and this work will be done shortly (I promise). * Bill has been working on the cathode construction document. He will circulate a draft shortly. - We will need to make up the metal cooling bracket pieces that attach to the preamp cards and lock the Cu cooling loops to the readout. We will go with aluminum for the prototype tests and hope that they are good enough. If necessary, they can be made from copper.
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.
Stack Assembly Procedures
- 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.
Cosmic Ray Test Stand
- We will be moving the FDC cosmic ray test stand from the Test Lab back to the EEL building. Beni is working on designing the room layout in EEL 126. The move of the cosmic ray test stand from the Test Lab does not need to happen in April as the planned magnet tests have been detailed for the time being. Still, we need to get things over to EEL for testing. - 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. - We would like to put together a bench test plan for the full-scale prototype within the next couple of weeks. This preliminary test plan will be used to provide information on what test stand fixtures to support the chamber we will require. Bill can then work on the design and get things prepared in the shop. Also, we would like to layout a design for the electronics before too much longer so that we can reduce time from when the full-scale prototype is constructed to when we get into the test plan. - 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.