Minutes 12-13-2006
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FDC Weekly Meeting
Date: December 13, 2006
Participants: Daniel, Brian, Simon, Tim, Chuck, Roger, Fernando, Elke, Kim
Next Meeting: Wednesday, December 20, 2006 @ 1:30 p.m.
Design Issues
> Do we want the STB capacitors inside or outside the gas volume? Pros: Kept with stable environment (reduce potential HV issues). Cons: solder flux (must be cleaned), contamination from components. ==> We decide to put them inside the gas volume. > Daughter board location on anode and cathode boards. - Tim and Chuck reviewed their work to position the cathode and anode daughter boards to ensure clearance with neighboring layers. - We decided to allow the connectors to run from mounting rail to mounting rail to spread them out to give sufficient space for connectors and cables. - Work needs to be done to make sure that there is sufficient room for cables in the 5-cm annulus surrounding the FDCs. Fernando provided the specs on the readout cables for cathodes and anodes. - Still need to iterate to define the extents of the different STB boards. - Roger and Kim will wait to layout traces until Tim and Chuck have completed their work. Note that with the multi-layer boards that will be employed, we will have to run traces on multiple layers to allow for sufficient ground shielding between neighboring signal lines. - Fernando also needs to converge on the exact size of his daughter boards. He is getting close and should have a preliminary design completed by the end of the week. - Fernando has identified connectors for the daughter boards and will pass this information on to Kim and Roger. These connects are surface-mount and come with the option of guide rails to help with the insertion of the daughter boards. > To give us flexibility in connector choices, we will increase the anode-cathode spacing to 6 mm from 5 mm. This more closely satisfies our electrode design rule-of-thumb of half-gap/cathode pitch = 1 as the strip pitch is now 5.5 mm. > The STB resistors will be placed outside of the gas volume, close to the daughter board connector. > Fernando has identified output connectors for the daughter boards with locks to keep the cables in place. > Fernando has been thinking about the LV design for the daughter boards and a possible bus distribution system. More details to come. > Simon and Fernando have worked out details of the FDC monitoring boards and readout. These boards should include temperature and humidity monitoring. > Brian will pursue construction of a carbon fiber annulus for the wire plane support frame. This may be stiffer than g10 to support the wire tension. This is the only frame in the FDC that doesn't have an o-ring groove (which is difficult to machine). > We reviewed the planned HV distribution for Roger. One mother cable (with 12 babies) per wire plane (6 sense, 6 field).
Budget Discussion
> PC Boards: Fernando provided a quote for the STBs and HVTBs from Advanced Electronics. > Daughter Boards: Fernando will send quote by the end of the week. > Preamplifiers: Fernando has gotten modified numbers from Mitch. He will provide them by the end of the week. > Cooling: Tim will put together a quote on a forced air/radiation system by the end of the week. Fernando liked the approach and believed that it should be sufficient. > Mounting and Support System: Tim will provide a quote for the rails, the adjustable height cart, transfer system for insertion, and cable support/strain relief system by the end of the week. > Ground Planes: Brian is working on this and will provide a quote by the end of the week. > Monitoring System: Simon will provide a quote by the end of the week. > Wire Winding: Brian will contact Karen Kephart this week.
Cathode Mechanical Mockups
- Brian is working on this to have all of the parts and pieces ready before the end of the year. As we had no time, the progress was not discussed during the meeting.
Minutes prepared by Daniel. Send any comments or corrections along.