Difference between revisions of "Minutes 11-8-2007"
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Latest revision as of 19:40, 8 November 2007
FDC Weekly Meeting
Date: November 8, 2007
Participants: Daniel, Brian, Simon, Roger, Bill, Kim, Chuck
Next Meeting: November 15, 2007
Contents
Manpower Update
- DSC reviewed (briefly) the manpower time-lines and work plans that he has prepared. He and Simon will meet with Elke this afternoon to go over the plans and then DSC will talk to the individuals matrixed into the project. - Several points of good news regarding manpower. 1). Kim will be changing over to 95% Hall D starting next week (she has been at 50%). 2). Elke has arranged for 50% of a Hall B technician to work on the FDC project starting soon (details to come). The plan is to have this person work to alleviate pressures on both Simon and Brian.
Magnetic Field Tests
- Simon has been working on the preliminary calibrations of the detectors for the runs taken. Simon and DSC will have separate analysis meetings to review the work and to discuss problems and issues. The group will be kept informed of progress as we go along
Composite Wire Frames
- Brian has begun work to construct the composite wire frames for the test stringing that is coming up this year. We plan on constructing 3 composite wire frames using the dummy boards with a medium density Rohacell insert and 2 composite wire frames with the dummy boards and a low density Rohacell insert. 3 of the 5 planes will be sent off for the test winds. At least one of these will include the low density Rohacell filler. - To progress on the construction, we need to construct an alignment jig to ensure that all of the circuit boards and filler boards are properly aligned during the lamination and attachment procedure. The current plan is to use the big aluminum tooling plate that Brian is using as the weight. The machine shop will machine in places to attach dowel pins over which the circuit boards can be placed during lamination. This same alignment jig will also serve as the tooling used during FDC stack construction. The dowel pins that will be used will have a slight taper at the end to allow easier construction. Brian will circulate drawings of his plan. He will be in contact with the machine shop to get this work completed with a week or two. - We discussed the plans for construction of the strong-back that will be used to keep the wire plane flat during the process of attaching the wires. This same strong-back, or a separate piece of similar design, will also be used during FDC stack construction to ensure that the wire frame will be easy to install on the FDC stack during construction. Brian has a rough design laid out. He will finalize the design and circulate for comments.
STB/HVTB Design
- We discussed the plans for the holes on the circuit boards. The current plan is to include slightly undersized holes of 3/16-in diameter where the through-rods will go. These undersized holes have been chosen to be of a size that matches with stock dowel pins. Once the wire frame has been constructed, we will complete the drilling of the through holes through the circuit boards, the Rohacell, and the solid G10 ring. - We also discuss some minor changes to the design of the geometry of the STB and HVTB boards. One thing that we learned from the design of the dummy boards is that we want to eliminate the long skinny sections of the PCB board. The second is that we want a much tighter tolerance on the overlap regions between boards so that they but nicely up against each other. Both of these issues are relatively minor changes to the design that involve minimal work to update. - Kim is working with several other folks to improve the efficiency of laying out the boards. Due to limitations of the CAD program her group is using, it is not easy to draw certain shapes at certain scales. She has worked to find a work around to this problem that will speed things up.
Wire Stringing
- Discussions continue regarding where the wire winding for the FDC project will occur. DSC has been in contact with the procurement folks at JLab to get them more involved in the organization and contacts. IUCF is now preparing a budget estimate that they should deliver to us soon. - In discussions with Elke, we have come up with a plan to write a statement of work for the project complete with all specifications and time lines, and then open up the project for bids. As there are only two competitors in this race (FNAL and IUCF), I think that we would have the best chance to get the best price, i.e. one that can fit within the FDC budget. - DSC will contact the folks at FNAL to bring them up to speed on where JLab is in the process. - Brian has completed the design of the wire frame transport/storage container and the paperwork has been signed. We expect delivery in about 2 weeks.
Cathode Board Readout
- Roger has continued to flesh out his design for making the connections between the cathode boards and the daughter board connector. He is nearly ready to order parts for a mechanical prototype.
Cooling Scheme
- Bill presented a CAD model of what he foresees is needed for the FDC on-chamber cooling hardware. It involves tubing lines, one for each package, that connect to a manifold located on each package. Lines from this manifold that run in loops up between the different layers that come into contact with the bracket on the daughter boards. This design introduces some new material into the frame region. Currently, his model includes a total of 2.5 kg of aluminum (brackets that thermally connect the cooling lines to the daughter boards), 18 kg of copper lines (which could possibly be replaced with aluminum), and about 1.4 kg of coolant. The options are water and fluorinert. > From wikipedia: It is an electrically insulating, inert perfluorocarbon fluid which is used in various cooling applications but is mainly for cooling electronics. The fluorinert would certainly be less harmful to our electronics compared to water in case of a coolant leak. - As a next step, Bill needs to meet with Fernando to go over the detailed specs of the cooling system from the standpoint of the ASICS so we can finalize the cooling capacity needed. Bill also wants to construct a prototype test system to do some cooling measurements in an environment similar to that the daughter boards will live in.
FDC Mini-Review
- Elke wants to have a meeting for the FDC system in December or possibly January to review the FDC technology choice. This meeting would most likely be with internal JLab experts. In order to be prepared for this review, we still have several important Monte Carlo studies that must be performed. This will be a priority for David Lawrence over the next month. We had a meeting with David, Mark, and Elke this week to go over the list of questions that need to be answer, a rough time line, and we identified the manpower to work on the various aspects of these studies. We will keep folks updated on progress. - This meeting and the results that come out of it are designed to help us better prepare for the formal FDC chamber review in March.
Work List
- The FDC short-term work list has been posted on the FDC web site (see http://www.jlab.org/Hall-D/detector/fdc/). 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.