Difference between revisions of "Minutes-12-11-2008"
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assembly drawings. The PR will be given to Elke in the next | assembly drawings. The PR will be given to Elke in the next | ||
couple of days. | couple of days. | ||
− | * The boards will be given a cursory QA checkout upon arrival | + | * The boards will be given a cursory QA checkout upon arrival |
− | then be test fitted into the cathode frames. Upon | + | and then be test fitted into the cathode frames. Upon |
− | tests, the remainder of the order will go out. | + | successful tests, the remainder of the order will go out. |
* Wire QA studies: | * Wire QA studies: | ||
* The QA checks for the sense wires are complete. | * The QA checks for the sense wires are complete. |
Revision as of 13:22, 12 December 2008
FDC Weekly Meeting
Date: December 11, 2008
Participants: Daniel, Bill, Mark S., Micah, Chuck, Roger
Next Meeting: December 18, 2008 @ 1:30 p.m.
Contents
Full-Scale Prototype Updates
- Procurements: * Rigid-flex assemblies: * Fernando and Roger have finished the design review and are now finalizing the language on the order specification and the assembly drawings. The PR will be given to Elke in the next couple of days.
* 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. * Wire QA studies: * The QA checks for the sense wires are complete. * Brian has prepared a slide for the SEM studies of the field wire and given it to the SEM folks. They will complete their work in the next few days. * Brian will prepare a final QA report with photos and test results for all wires when all studies are complete. * Brian checked with the purchasing agent responsible for the wire order to find out what QA qualifications were part of this order if any. Apparently they were not part of the order. It is not clear what happened. Was this a miscommunication or a did somebody drop the ball? * G10 ring order status: * No new news. Expected delivery date is any day now. This order includes the G10 for all FDC wire and cathode frames. * 110IG Rohacell order status: * No new news. Expected delivery date is Dec. 17. This order includes the G10 for all FDC wire and cathode frames. - 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 - Bill has completed a draft of a specification/tolerance document for the wire frames. - Bill has worked with the JLab machine shop to do some tests of the system to do vacuum bagging on the G10/foam laminate. While things did not work fully has Bill had hoped, he declared that we are ready for preparation of the G10/foam laminates once the orders arrive. - The test laminate that was made by Mark (consisting of G10/foam) was seen to be highly warped last week. This week it is flat as a board. Neat! The issue is due to humidity. We will modify the construction document to give some time for the frame to sit in vacuum to pull out all water before machining and assembling. - The templates for cutting the foam core pieces have been completed in the JLab machine shop and are in our possession. Bill will look into having these pieces anodized (to make them more resistant to nicks and dents). We will also consider having their surfaces treated in a simple way to avoid oxidation. - We reviewed the remaining machine shop work for the wire frames. After construction of the G10/foam laminates is completed, these pieces will be machined for through-holes. These pieces will then be laminated to the PCB annuli using our vacuum bagging procedure on the construction jig fixture. - The Phase 2 contract with IUCF for winding the full-scale prototype has now been signed by all parties. Our window for getting the completed wire frames to IUCF is from the middle to end of Jan. 2009. - Kim has provided a draft of a procedures document for the Phase 1 and Phase 2 wire frame PCB component attachment. She has merged this document with Fernando's cleaning and handling document. The document is being finalized with some additional language on soldering iron temperature vs. time profiles. It must be completed before the start of the Phase 2 component soldering.
Cathode Planning
- 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 * Bill has asked for some modifications to the specific tasks for the cathode edge cutter. DSC will work on the language and pass this on to Chuck for inclusion. * Copies of the timeline were handed out to folks for reporting on their work progress. * DSC will replace Micah's name on schedule with Mark S.'s name for all work required in 2009. - Bill has completed a draft of a specification/tolerance document for the cathode frames. - Bill has completed the design of the cathode edge cutting system. He is finalizing the fabrication drawings and then the procurement will begin. Some of the parts actually have already been ordered and delivered to JLab. Some machining work is necessary and we are trying to figure out the quickest delivery/lowest cost option now. After assembly of the system, we will work through a full test plan before cutting any of our "real" cathodes. - Still waiting on an updated version of the cathode construction document. Bill has this now and will get back to it soon. This will need some priority soon. - Before construction of our first "real" cathode for the full-scale prototype, all tasks must be prototyped with final procedures! We will be making (at least) one more cathode mock-up using the final procedures. Note: The tensioning of the cathode will be done with a full cathode frame laminate, not just a G10 annulus. DSC will talk to Brian about this. - Minor design problems with the cathode tensioning system are being addressed with some work done by the machine shop. Some of the work has been completed (adding a filler piece on the aluminum jig plate) and others are in progress (associated with the arm holding the laser). - We need to begin considering construction of the cathode sandwich prototype. It may be that we will want to construct a prototype before making our first "real" cathode for the full-scale prototype. This discussion will take place next week. There may be issue with connecting the ground plane that will require study and machining of frames. - We looked at the ground connection prototype and will talk about it more at our next meeting (where more folks will be present). - Brian has cut off a piece of the 2-micron cathode prototype and put it into a mini-stretcher. Eugene and Brian found that the design of this tensioner (square with only 4 tightening bolts - 1 in each corner) was inadequate. It caused board puckering, resulting in different tensions in different portions of the board. The mini-tensioner has been given to the JLab machine shop for modifications. The board will be tensioned to 400 N/m and the distortions of the electrodes parallel and perpendicular to the strips will be measured. Studies of the board distortion on this real board material are crucial to our design approach. More to come soon. - Mark will perform some handling tests on the 2-micron board that will be typical during construction to ensure that we have techniques in place to reduce handling defects. More to come.
Cathode flatness measuring system
- It was verified that the problems seen in the scan data presented last week by Micah were due to rail misalignment problems. The rail was reset and the granite table surface rescanned. It seems that a rail misalignment still remains, although at about half the level it was at before. - The JLab Survey Group came in and surveyed the granite table. It is very flat (as it should be darn it). Details from their report were provided in a data document provided by Bill. - Micah showed some data from scans of the high-tension (600 N/m) cathode at 4 different rotation angles. See his talk slides for details. Presently Micah analyzed the data using a linear correction function for the rail misalignment. We discussed the preferred mode of actually subtracting the granite table measurement from the cathode data. This is a bit tricky now due to data handling. We may revisit this issue. There was a problem with the data that Micah acquired that he found that the frame was fully tightened down to the granite table. Micah will redo the scans. - Bill has asked for Micah to remeasure the granite table surface as a reproducibility check of the system. - Micah would like feedback from the FDC Group on what data we would like back from the scan. DSC talked to David after the meeting and discussed two types of data: 1). data that shows the electrode surface bowing, which can be somewhat coarse in binning (say 1 in by 1 in bins), 2). data on with finer grid size to look for sharp surface defects. - 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. - Documentation of the system continues. See the FDC wiki wiki page for details.
Spacer Design
- Bill has declared that the spacer ring will have two o-ring grooves. This is the best solution (and most viable). He will move to have the machine shop prepare the polyethylene and poly propylene rings. These will be complete spacers, and thus, will include the o-ring grooves and the gas plumbing. Bill will also order the remainder of the material needed for the full-scale prototype.
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.
Gas System Design
- Slava has worked on a preliminary layout of the gas handling system for the CDC and FDC. He provided two options for the FDC system design that were essentially a basic version and a fancier version. Slava's design work was based on the original concept that Brian came up with long ago. We will continue the design work as we have time.
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.
Small-Scale Prototype
- 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.
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.