Difference between revisions of "Minutes-9-4-2008"
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==Work List== | ==Work List== | ||
− | - The FDC short-term work list has been posted on the | + | - The FDC short-term work list has been posted on the [http://www.jlab.org/Hall-D/detector/fdc/ 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. | Minutes prepared by Daniel. Send any comments or corrections along. |
Revision as of 16:26, 4 September 2008
FDC Weekly Meeting
Date: September 4, 2008
Participants: Daniel, Simon, Fernando, Mark, Kim, Roger, Chuck, Eugene, Bill, Micah, Herun, Jim, Beni
Next Meeting: September 11, 2008 @ 1:30 p.m.
Contents
Full-Scale Prototype Updates
- Clean Room: * Brian is working to put our clean room/tent together. He has gathered sticky mats, gowns, hats, gloves, shoe covers, cleaning equipment, trash cans, etc.. He has ordered a few things such as sticky rollers to clean the area that will arrive soon. He will get a bench and a storage closet soon. * Brian and I are now finalizing a procedure for entering into and leaving the clean space that we will all have to follow. After this procedure is finalized, we will all meet at the clean tent have a walkthrough of everything. As of now, we will be following full clean room procedures in the tent. * Someone unplugged the clean tent and we do not know who. Simon will post signs on the clean tent for contact information should there be any questions. * Alexandre Deur's group needs 220 V power and has asked if they could borrow our outlet. There is another outlet on the side of the clean room by the viewing window that can be used potentially. DSC will talk about this with Brian upon his return from vacation next week. - Procurements: * Roger is still working to finish the design work for the cathode rigid-flex assemblies. He still has several days of design work to do and hopes to put the order together in the next several weeks. We will be ordering enough of these assemblies to outfit the entire full-scale prototype. The final number (roughly 70) has yet to be finalized. * Kim has completed the PR for the signal cable connectors and for the manufacture of the LV cables. No word yet as to delivery date. * Elke asked us to prepare a spreadsheet listing all expenditures for the full-scale prototype. Kim has started to prepare this including all of her procurements (including those through Fernando) and those of Bill. She still needs input from Brian, Roger, Lorelei, Simon, and anyone else who has order parts n' pieces. We will post a draft of this spreadsheet in an accessible place shortly. * Brian is working on the procurement of the sense and field wires for the full-scale prototype. DSC has prepared two documents for our wires: Wire Specifications Document and Wire Testing Document. These documents have been passed on to the wire suppliers. More discussion on this when Brian returns. These documents are posted on the FDC procedures web page. - Fernando has considered how we will make the connections from the HVTBs to the power supplies. He has identified a connector that will connect to the baby cables soldered to the HVTB and the cables that go to the power supply. Bill is working to put the connectors into the 3D CAD model and to detail how they will be attached (as they are quite massive). Once we get some of these details worked out, we will discuss when we want to place the order. - Brian identified a group that can do our SEM wire studies. Brian brought them our already prepared sample from our earlier SEM tests to see if they are content with our slide. Note that our new SEM contact can be used to study a sample of the cathode board that we received from Allflex. Fernando has prepared the sample and given it to DSC.
Cathode Planning
- Roger heard from Allflex on Tuesday. Five of the six 2 micron Cu boards were done and they are working on the sixth. Once this is done, they will move onto the 5 micron Cu boards. We should expect delivery in about 1 week. - We have not yet devised methods for handling the boards when they arrive from Allflex. This will have to be developed once the boards arrive. Presently we are planning on doing a battery of QA checks on all boards in the first order. - Bill has not done any more work on the system to cut the cathode edges. More to come when he gets back to this. - Bill has gotten a hole punch for cutting out the center of the cathode boards. He will gather the necessary parts and pieces to do some test cuts. It also turns out that Allflex will send us the punch that they had purchased for our job (before we told them not to do this). This work will proceed shortly. - The nominal plan as of now is to set the cathode tension on the boards and then to add the central hole. We also are not planning to add additional gas holes in the active region of the cathodes. - DSC and Chuck have completed work (for now) on preparing the R&D schedule for the cathodes. Copies of the plan have been circulated to all folks involved. Please consult this regularly as you plan your work to understand better the order and the time assignments. Contact DSC with questions. - Cathode flatness measuring system: * All parts n' pieces have arrived. The machined parts from FSU have apparently not arrived. Bill will check into this. * Mark has prepared the stabilizers for the granite table and is working on attaching the pieces for the rail installation. * The plan is to move the granite table to the EEL building early-ish next week. * Micah is standing by to install/attach his parts n' pieces to the system once Bill and Mark are done. * Micah reported on work that he has been doing to generate contour plots of the surface flatness from the 2D data. He has sent around some sample plots for folks to look at, but he still has some work to do. * We will have to work out a time-sharing plan for the laser measurement head for the flatness measurements and the tension measurements. - Eugene has posted GlueX-doc-1090 containing all details regarding his studies on the cathode tension measurements and the allowed flatness variations. He believes that if we can keep the flatness within 200 microns, we will be in good shape. - Brian and Bill should begin to layout a detailed outline for the cathode construction steps and circulate for feedback.
Wire Frame Construction
- The frame that was used for our wire tension load test (which is discussed in the FDC TDR) has been modified to include the pockets for the rigid-flex assembly and the bolt holes. It was machined to the nominal I.D. and O.D. of our wire frames. The foam core and the G10 skin were removed to an I.D. of 1032 mm to account for the problem with the HV decoupling capacitor placement. The plan is to redo our loading tests and measure the in-plane and out-of-plane distortions of the wire frame up to a load of roughly 50 lbs (the full wire load is about 35 lbs). Bill is working on the FEA calculations to determine the loading limits for the frame. This will also tell us how high in tension we can go with our load test, which uses a single wire down the middle of the frame (which is significantly worse that the distributed load of the real frame). - The nominal wire frame construction plan devised by Brian will be updated by Bill before the start of wire frame construction. The current version of the plan is posted on the FDC web page under the procedures link. It will be updated when Bill is done working his magic. - We are presently planning on borrowing an A-frame for EEL 126 for the wire frame construction (that Tim arranged). No other frames could be found in storage that we could claim. - The PCBs for the FDC will need to be handled by all folks involved with more care. Many of the boards have sustained damage to the fragile lap ends. The damage is not severe enough to cause any construction worries, but handling procedures do need to be established and followed. - Kim has started to move the decoupling capacitors on the back side of the STBs. She has nearly completed work on one board. All capacitors will be inward of D=1020 mm! The o-ring lives again.
Test Frame Wire Winding
- IUCF has supplied the official report from the Phase 1 wire winding continuation and an official budget for Phase 2. We will have a teleconference with IUCF upon Elke's return from vacation.
Spacer Design
- Since our last meeting more thinking about the design of our spacer ring has been done. Last week we discussed the possible advantages of laminating the ring directly to the face of the cathode. Bill is souring on this idea as this would not give us the freedom to interchange the cathode boards due to the required positioning of the gas inlets and outlets on the spacer. For the full-scale prototype Bill is content to live with a spacer ring with two o-rings. - Bill has not yet finalized a choice of material. It looks like the best choice may be polypropylene. He would prefer nylon-6 due to its superior mechanical properties, but nylon-6 absorbs water like a sponge. One problem with polypropylene is that it is very difficult to epoxy to it. If this ring has o-rings on both sides, there is no problem here, but Bill needs to be able to attach the gas inlet and outlet tubings. He described a number of potential work arounds. - We will be working to make a mechanical prototype as soon as the design is finalized.
Stack Assembly Procedures
- DSC, Brian, Tim, 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 use 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.
Gas System Design
- Slava is working 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. Slava provided some drawings that DSC will review. We will then 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. - 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.
Small-Scale Prototype
- Simon and Fernando are in the home stretch on completing the specification of the cathode and anode ASIC dynamic range. All required measurements have been completed and work is ongoing to finalize the test results in the document. What we have so far is posted as GlueX-doc-1070. - Yves Van Haarlem from CMU visited JLab yesterday to meet with Simon and Fernando on the work to specify the ASIC dynamic range for the CDC. Simon will post minutes from this meeting shortly on the GlueX wiki under the Tracking Meeting link. - We still have the lingering issue of the problematic x-y plots from the 2-micron Cu cathodes. Simon will revisit this problem by taking some new pulser calibration data to see if this makes the apparent problem go away.
CAD Model
- We discussed a bit about making sure all relevant design features of the FDC are in the full CAD model. Tim will have Slava work to put in the capacitors and resistors on the wire frame PCBs into the model.
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.