FDC Weekly Meeting
Date: August 22, 2007
Participants: Daniel, Simon, Chuck, Tim, Kim, Roger, Fernando
Next Meeting: September 5, 2007
Composite Wire Frame
- Brian has completed making the composite wire frame. We are presently awaiting the machining of the o-ring groove and the through-holes. This is being handled by the JLab machine shop and they indicated that this work will be completed before the end of August. Stress testing of this frame will then follow.
- No new work since last week. This is on Brian's to-do list. All pieces (G10 skins and Rohacell core) are in our possession. Brian will use the existing 3 piece dummy cathodes. The plan is to make a complete full-scale cathode.
- Roger sent a Gerber file of the two piece STB and HVTB design (just showing outlines of the overlapping boards) to Sierra. They indicated that the size of these boards is not an issue. So we have a final design that the STBs and HVTBs will be a two piece design. - Kim is back on the FDC project after several weeks away on other work. She will begin laying out the final design for the full-scale prototype. Work will begin first on the STB and then the HVTB will follow. She has no questions at the current time and should have an initial layout by next week. - Roger and Kim will prepare designs for "dummy" STB and HVTB circuit boards in the next week. These circuit boards should contain the solder pads and the sighting fiducials. They will also prepare the "junction" boards that go between the STB and HVTB. These boards are needed for the test winds that are scheduled at FNAL later this year.
Magnetic Field Tests
- Preparations for the magnetic field test with the small-scale prototype continue. We have installed the lower set of 4 MWDCs that make up half of our cosmic ray telescope. The upper set of 4 MWDCs will be installed after a light above the magnet is removed on Thursday. We will then installed the small-scale prototype chamber inside the magnet. We will then work to optimize the grounding configuration of the system and then perform alignment of the chambers as best we can in this rather confined space. Gas is flowing through the installed chambers and all cables have been strung. We should be ready on Monday of next week to begin check out of the data acquisition system.
- The FDC daughter boards should be in our hands within about a week. Fernando will then mount the ASICs and perform some tests. We will need to be ready to install these boards on the small-scale prototype in October. - In order to be compatible with the small-scale prototype, we need a transition board to go between the chamber and the daughter board. Fernando is beginning work on this board and it should be ready in about 1 week. - The daughter boards will be compatible with the gain/shaper modules that Gerard provided. To read out the entire chamber, we will need 3 more cathode boards. Fernando will contact Gerard about making more of these boards. Also Fernando will talk to Gerard about what we should measure with the ASICs on the small-scale prototype.
- We need to place our orders for procurement for this fiscal year by September 4. This includes the shop charges for the wire frame, dummy circuit boards for the wire frames, a spool each of field and sense wire, additional G10 skins, and shipping funds to send a sample of the readout cable to Gerard. - Brian was not in attendance at today's meeting so Simon will contact him this week to prepare the PRs for the procurements. The shop charges should be incurred this month according to what we know. The cable shipment to Gerard is awaiting the arrival of our cable from Spectrastrip.
- No work done on mounting the +/-75 deg cathodes yet. This is on Brian's to-do list.
Cathode Rough Out
- This week Roger will begin work on laying out a rough design for a cathode board with a hole in it about the beam. Actually there will be no physical hole, we will just not have copper there. We plan on reading out strips above and below the hole. While we plan on having a package-dependent deadened region on the sense wires, we would like to have a single cathode design. We must keep in mind that the readout is quantized into 24-channels. The hole should be 3 cm in radius. Once Roger has completed this layout, he will circulate a file for us to consider and discuss.
Cathode Board Readout
- Our current design plans call for a flex-type cable to be epoxied or soldered to the face of the cathode plane and then to route through the cathode frame (through a cut out) to the daughter board connector on the back side. We had a general discussion on possibilities and options for this connection. After Roger completes the work on the cathode rough out, he will begin work on a design for the connections. We would like to be able to build a prototype of this connection scheme and have this done by the end of this year.
- Simon and DSC will update the TDR prepared for the chamber review in March to reflect the current FDC design. We will then prepare a few page summary as the deliverable to DOE. This report is due at the end of September.
- 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.