Difference between revisions of "Minutes 7-18-2007"
From GlueXWiki
(No difference)
|
Latest revision as of 12:57, 25 July 2007
FDC Weekly Meeting
Date: July 18, 2007
Participants: Daniel, Simon, Brian, Kim, Roger, Tim, Chuck, Fernando, Joe
Next Meeting: July 25, 2007
Contents
Cathode Updates
- There was a bit of a misunderstanding on the reasons why Sierra, Optiprint, and others were turning down our request for manufacture of the cathode boards. This had to do with the physical size of the boards needed for the full-scale chamber, and not with the requirements of the boards themselves. Elke thought it best if we gave the other companies the opportunity to make the boards for the small-scale prototype and to not pay the $14k setup charge to CCT. This may save us some money down the road if we do not end up using the cathode readout for the FDCs. - Brian sent around the Gerber files for the small-scale chamber to get quotes. - CCT called Brian and changed their attitude quickly regarding the setup charges once he told them about getting quotes from the other companies. They will let him know about the quote for the small cathodes in the next few days. They are confident that they can make them.
Prototype Design Planning
- DSC talked with Elke regarding how much design work we should pursue as we wait for answers regarding the performance of the cathode design in a magnetic field. She fully supported us pushing ahead on the design of the full-scale prototype. - Kim and Chuck provided lists of questions that they need to get answered before they can continue on the design. DSC will work offline to get these questions answered and communicate the work to the folks doing the designs. - DSC stated that our goal is to complete the design of the full-scale prototype chamber by September. - Fernando discussed his idea to use the same preamp daughter boards on the cathodes and the wire planes. Thus now all daughter boards will be 24-channels. This will require a special version of the F1 TDC, but Fernando believes that this would have to happen anyway. The current F1 TDCs are 64 channel, but they are extremely dense and there is no space on the boards for the required calibration circuitry needed for the FDC. The new F1 TDC is envisioned to be reduced to 48 channels, which will leave sufficient space for the calibration circuitry. Fernando indicated that he most likely would be the person to do the design work.
Frames
- The parts and pieces for the second wire composite wire frame should be arriving next week. Brian will put this together and then tension it. He will compare the deflections to the numbers computed by Tim. - This new frame will have the final 5-mm thickness required for this frame (as opposed to the first composite frame that was cobbled out of existing pieces and was 6-mm thick). Brian will use high-density Rohacell in the inside. - This second composite wire frame will also be used for long term stability testing of the design.
Prototype Cathodes
- Brian has ordered some 2-mm thick Rohacell that should be arriving next week. This material will be used to make a new dummy cathode with this Rohacell as backing. We will then perform flatness measurements on the cathode. As these measurements have to be done with the plane laying horizontally, we will outfit the backing layer with a dummy layer 3-mm thick to eliminate the gravitational sag.
Magnetic Field Tests
- Much planning for this test is in progress. > DSC has arranged for some wire chambers to be borrowed from IUCF to serve as our cosmic ray telescope and they should arrive first thing next week. > DSC and Simon readied the electronics, cables, and gas racks in the test lab for movement to Hall B. Last Friday they were transported to the Hall and craned into the downstream alcove. > The dipole magnet that will be used for these tests will be reconnected and tested next week. Field maps will then be performed and we should have access to the space in about about two weeks. > Simon has prepared a TSOP for the test period and turned the paperwork in for review and signature. > DSC will work with the Hall B folks to prepare the TSOP for the magnet operation. > DSC has prepared a detailed checklist for work to prepare for the test run. > Simon and DSC are finalizing the test plan.
Daughter Board/ASICs
- It seems that folks are very keen on getting feedback on the ASIC performance on a real detector in the short term. This will be necessary to provide feedback to the chip manufacturer and to Mitch Newcomer about the performance and the next round of modifications. - Fernando and Gerard had an exchange via email regarding what needs to be done to enable compatibility of the daughter board with the ASICS with the small-scale prototype chamber and the readout. We will have to construct a go-between board to mate the daughter board to the small-scale prototype. We may also need to construct a patch panel on the read-out side. The main issue is the input and output connectors on the daughter board and compatibility with Gerard's shaper/amplifier board. - Fernando has been charged to get this worked out, to design the go-between board, and to interact with Gerard so that we will have the boards and connectors needed for these tests by September.
Simulations
- We have scheduled a meeting to discuss the Monte Carlo results for the FDC tomorrow morning. There we will finalize exactly what studies we want to perform and the priorities. The work that needs to be completed includes: > comparison of photon conversion probability in the inactive area (frames + cables) between the latest FDC design to the FDC design presented in the chamber review. > rates per strip and wire for the latest FDC review. > momentum resolution vs. momentum and angle for the latest FDC design. - David Lawrence will be spear-heading the work in consultation with Richard Jones and the IU folks (Mijailo and Matt).
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.