FDC Weekly Meeting
Date: July 23, 2009
Participants: Daniel, Mark I., Bill, Simon, Brian, Fernando, Mark S., Rich, Eugene
Next Meeting: July 30, 2009 @ 1:30 p.m.
General Construction Updates
- Mark S. will be working exclusively on the solenoid for the next 5 days. We will have to absorb the manpower hit and deal with it. - The parts for the assembly jig on which the detector stack will be constructed will be put together as there is time. - Bill will take on the preparation for a stack assembly document. A draft will be prepared before assembly of the full-scale prototype and then fleshed out during the process with relevant photographs taken. - The composite frames for the two gas windows are in progress. So far the Rohacell core has been laminated to a G10 ring. One more G10 ring to go to complete the frame construction. The exposed Rohacell will then be sealed with epoxy. - Mark S. prepared the PO for the cables that will be used to attach to the cathodes for the external ground. He will also order the sealing epoxy that is used to cover the conducting epoxy. The cables and associated pins should be here in a couple of weeks. The epoxy order has not yet been placed. - Rich will only be working with us for another couple of weeks before going back to UMass. - We need to be out of the clean room by the end of September. We are also thinking of carving out more space in EEL 126 for addition of a clean tent for construction.
Wire Frame Update
- Brian repaired a third wire plane (called P4). Efforts were made to clean the solder flux off the boards, but residue remains. Rich has done a series of high voltage tests. One of the field wire busses on the HTVBs is drawing sizeable current. After visual inspection for debris and cleaning the PCB for a second and third time, the current on the supply dropped from 50 uA to 15 uA. We are still devising better ways to clean the boards. Of course the boards should have been cleaned at IUCF immediately after the soldering was done. This will be mark of the Phase 3 discussion. - During inspection of the P4 wire frame, it was discovered that some of the components had the wrong values, some components were not properly soldered, some components were missing, and some were bad. A full check out has been done and Rich has prepared a list of components for repair. All other wire frames will also have to be rigorously checked. - We need to have a dedicated meeting to design what the schedule for work on the Phase 3 wire winding will be. The highest priority for work scheduling will be doing work on upgrades of the wire winding facility. This includes a better strongback design, the design and construction of precision combs, modification to the wire winding table, and a list of other items with the system. Stay tuned, more to come. - The wire frame construction document is located at: /u/group/halld/Engineering/PRELIMINARY DOCUMENTS. We will include the information on the wire electroplating process shortly. - The parts of the jig to use for the wire electroplating operation are in our hands. They will be assembled as we find time. - Brian received the SEM scans for our wire from the W&M folks. He will generate a final QA report with photos and test results for all wires when he gets a chance.
- Progress updates: * The edge sealing and gas hole inclusion has been completed on all of our cathode frames. * The 7th and last cathode has been tensioned and will be laminated to its frame this afternoon. * It was found that two of our 2 um Cu cathodes were made incorrectly with the center panel rotated by 180 deg. Bill has come up with a way to modify the frames and to modify a couple of cooling clamps to get around this. These two frames will have to be on the outside faces of the chamber. The layer with the two 5 um Cu boards will be in the middle of the prototype. * We will modify the layout of our cathode panel alignment fiducials to allow us to catch panel rotations. Details will be passed on to Roger. * One of our completed cathode boards is really contaminated with epoxy near the two seams. The epoxy manufacturer is sending us a solvent that they believe should allow the epoxy to be removed. It will arrive next week and we will carry out some tests. * The completed cathodes are sitting in a nitrogen environment to reduce the oxidation problems. * We have a bit of a back up doing the flatness scans of the completed cathodes. Mark S. has taught Brian how to complete the scans and a scan will be done this afternoon. - Bill stepped us through a work plan for the construction of the two cathode sandwiches for the prototype. This work will begin next week with the tensioning of the ground planes. - Bill is devising a work plan for the prototype construction that he will give to Chuck to put into a schedule for tracking. - The Fast Electronics group is handling the soldering of the rigid-flex assemblies. They now have all of the necessary components. The boards arrived poorly packaged and were noticeably warped. This has made the assembly tougher. Fernando came up with a scheme to deal with this, and the work to mount the components is underway. A QA plan for the finished boards needs to be put in place. - Bill has been working on the cathode construction document building in the pictures that are being taken. The current draft of the document is located at /u/group/halld/Engineering/PRELIMINARY DOCUMENTS. - We are standing by waiting for information on the PR for the 2-um board material. We have learned that the order has gone out, but the Japanese company has still not indicated whether they will fill the order. A second company that can produce the board material has been identified. - 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.
Cooling System Tests
- Fernando is in the process of writing up the results from his cooling system studies. Stay tuned for the GlueX note. He indicated that he is back to work on this document and it should be done shortly.
Cosmic Ray Test Stand
- Beni is continuing work to setup the cosmic ray telescope and test system in EEL 126. Progress is slow and steady. The gas tubing is in hand and will be laid out shortly. - 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 is presently working on it after incorporating feedback. It was also suggested to send it to Curtis for feedback. He will post it as a GlueX-note shortly. - The machined parts for the support/rotation of the full-scale prototype in the cosmic ray stand have been delivered. We are awaiting some purchased parts to arrive. After we have everything in hand, it will be assembled and test fitted.
- 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.