Minutes-3-19-2009
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FDC Weekly Meeting
Date: March 19, 2009
Participants: Daniel, Beni, Brian, Mark S., Mark I., Kim, Eugene, Fernando
Next Meeting: March 26, 2009 @ 1:30 p.m.
Contents
Full-Scale Prototype Updates
- Cathode Board Orders * Cathode boards: Roger received price estimates from Allflex. The remainder of the cathode order for the full-scale prototype will be about $13k. The design work on the boards is done and Roger should have the cathode board PR to Eugene by Monday or Tuesday of next week. * We have seen evidence of corrosion on both the 2 micron Cu and 5 micron Cu boards. Mark has taken photographs and will have Greg Adams take some more. Next week when Simon comes back, we will compare the original board photographs with the latest to see if there is any evidence of corrision since the boards arrived. Roger has already had some communications with Allflex on this, but we will provide them more information shortly. Allflex has already proposed adding a second deionized water rinse in the manufacturing process to remove any additional developer. More to come. * Cathode daughter board: The board is design is done and checked. This order will go out shortly after the cathode board order is complete. - Chamber Wire: * Brian talked to the SEM folks and their new machine has arrived. The operators are getting trained and they should be ready to complete our wire measurements in the next couple of weeks. Brian will prepare a final QA report with photos and test results for all wires when all studies are complete. - Mark S. is 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.
Wire Frame Update
- Status: Two wire frames (P4 and P1) have been wound. A series of tension measurements and position measurements have been completed and the data has been transmitted to us. * The tension measurements for both the sense and field wires appear to be reasonably within our 5% tolerance specification after we account (qualitatively) for the wire load distortions of the wire frames on the strongback. Bill wants to do some better FEA modeling to understand the wire frame distortions. * The position measurements show a systematic issue that gives the same behavior on both wire planes. After investigation, two issues have arisen. The first is that there is a plastic seal/covering on the linear transducer that is broken and aged right at the position where the position anomalies appear. Also, there appears to be a discrepancy between the encoder data at the readout computer and at the readout electronics. We do not believe that we have accurate measurements for the wire positions. IUCF believes that the true wire positions are better than the position data reveals. This is based on studies with the Moire pattern mask. * The third wire frame is being glued today and will be soldered tomorrow and the fourth wire frame will be glued and soldered in the first part of next week. * The company that made the linear transducer still exists and can refurbish the piece for $1.5k and claim a 7 business day turn around. We have given IUCF the go-ahead to have this work done and charged to the Phase 2 contract. Bill feels that this is essential to do. - 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. A new version will be posted when his work is done. - Brian will be working on fine-tuning of the wire electroplating process using one of the full-scale wire planes from Phase 1. This work will take place on Tuesday. Brian will produce a procedures document with photographs of each step for this work. - 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 after his return.
Cathode Construction
- We reviewed the cathode R&D timeline. We did not have an updated schedule to go over as both Chuck and Bill are away this week. 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: * All cathode boards from the first order have been trimmed. The work was deemed quite satisfactory. We should prepare a procedures manual for this work including our lessons learned. * The G10 pieces for the cathode frames are on order and should arrive at JLab within 2 weeks. * As we don't have the associated frames, we decided to go ahead and make up 3-piece cathode panels and put them in storage. So far, one 5 micron Cu board panel has been prepared. It will be moved to storage this afternoon. Work on further panels will continue this week and next. * We will use Roger's sample cathode daughter boards with the mechanical cathode sandwich prototype to study the clearance and space between neighboring cathodes. This will happen next week. * 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.
Stack Assembly Procedures
- We 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.
Documentation
- 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. This move should be probably take place in April. - 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 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.
Work List
- 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.