FDC Weekly Meeting
Date: July 3, 2008
Participants: Daniel, Simon, Brian, Fernando, Mark, Jim, Elke, Eugene
Next Meeting: July 10, 2008 @ 1:30 p.m.
- Roger sent the PR around for feedback and comment. Necessary blessings have come from Fernando and Bill on the layout and design. Elke has provided procedural instructions that have been taken into account and she signed the paperwork. The PR has been sent on to procurement. As soon as a delivery date is better known, more details will be provided. - Fernando discussed the electrical testing plans. The biggest thing for checkout and board qualification is to complete a series of resistance measurements on all boards. This includes the resistance of each strip and the isolation between neighboring strips. While inter-strip capacitance measurements will be needed at some point, they are not necessary for vendor qualification. Fernando will check around to find out if someone has an appropriate unit that can be borrowed (e.g. from the SVT group in Hall B, from Gerard, or from Mitch). Fernando will put together a test plan document (including proper handling specifications) and will circulate it for comments and feedback. We want to have the plan finalized and all equipment on hand to begin testing as soon as the boards are in our hands. This should be in roughly 3 weeks. - We briefly reviewed the current concepts on how to cut the precision edges on the cathode boards. We will work to develop a plan and order what we need to complete tests before cutting the real boards. - Fernando had some feedback for Roger the rigid flex assemblies. We will follow up with Roger on his plans. Fernando believes that with the new design for the assemblies, further solder tests will not be necessary. - Roger is working with the Allflex representative to find whatever information is available from Nippon on the raw material specifications. - Due to the height of the solder connection between the cathode board and the rigid flex assembly, we will have to revisit the design from the standpoint of adding clearance pockets on the surfaces that mate up against this solder region. Chuck is responsible for looking into this and letting us know. - Brian will modify his Lucite box design for storage of the completed cathode planes. The cathode planes can stack upon one another (unlike the strung wire frames). As this box is not needed for at least several months, this work is not super high priority. - We should check with Allflex to have them let us know when the shipping box has been delivered.
- Brian checked on the status of our granite table order. The word now is that the table will not arrive until the first of August. - The work on the assembly jigs is in the queue in the JLab machine shop. The work should be completed by the 3rd week of July. - Brian checked on the electrical work to connect the clean tent to power. It has not started yet and he will follow up on this to find out when it will be done. We will also agree to let another group use the clean tent before we move in as we are behind schedule. Brian will provide a statement on this to Elke, who will pass it along to Dennis Skopik. - Brian and Bill will work to update our wire frame construction sequence document. Brian will provide a first draft to Bill who will work to polish it up. We would like to provide this to Casey so his group (and of course ours) can full understand the procedures. This work has not yet gotten underway.
- DSC circulated a cathode R&D planning document to the group for feedback. Feedback should be provided over the next week to finalize the task list. DSC will then use this to create a work time line so that we can understand the impact on the FDC construction schedule.
Test Frame Wire Winding
- Elke has signed the paperwork for the continuation of the Phase 1 wire winding contract with IUCF. The paperwork has now been moved on to the contract folks and will be finalized very shortly. - The shop completed work on drilling holes in our wire frames (after some priority negotiations with Elke). DSC and Simon packed up the shipping crate with two frames and it was sent to IUCF on Monday. The frames arrived at IUCF this morning and they will inspect them for any damage incurred during shipping. - Brian will provide information on the two frames so that we can tell IUCF which frame to use for the winding tests. - DSC is working with Steve Christo to prepare a wire specification document for the tungsten and CuBe wires leading up to procurement. Steve is preparing a document for the Hall B chambers and we will most likely adopt this document for Hall D. DSC reviewed the existing Hall B documents to give folks a flavor of how these documents have been prepared in the past. We need to make decisions on what is required for the FDCs.
Stack Assembly Procedures
- DSC, Brian, Tim, and Bill will work to finalize the stack assembly construction document that has been prepared. This document should be in place before we get too far in the construction process.
Cathode Flatness Measurements
- Micah is working on upgrading the system readout electronics. He prepared a time line for the system work and DSC reviewed it for completeness. - Micah completed a series of flatness measurements on one of our backed cathodes and our high tension cathode. The backed cathode shows a surface flatness profile that has a 6 mm range! Yikes. The high tension cathode has a flatness profile range of 200 microns. Micah did measurements with the laser running along the strips and transverse to the strips. These profile data have some very interesting and complex patterns that we need to understand a little better. We also need to study the effect of these surface profiles on our cathode coordinate reconstructions. Is the value that we have in our resolution error budget table sufficient? - Micah and David put together a list of parts 'n pieces for the measurement system upgrade. DSC has worked with Lorelei to order the parts. They should arrive in a week or two and then the upgrade work on the system will continue. - Micah still needs to perform flatness measurements as a function of rotation angle so that we can better understand the effects of gravitation sag on the cathodes.
Cooling System Tests
- Fernando has completed a series of tests of the cooling system as a function of the temperature setting of the water reservior for fixed flow rate. A flow control valve has just arrived an will be installed next week. The plan is to perform more cooling studies as a function of flow rate for fixed temperature. Fernando will prepare a GlueX note when the studies are finished.
Gas System Design
- Vladislav (Slava) Razmyslovich is working on a preliminary layout of the gas handling system for the CDC and FDC in preparation for the upcoming systems review. We will sit down with him in a specialized meeting to review the design concepts when we get a chance.
- Kim needs to provide an instructional writeup for the Phase 1 and Phase 2 wire frame PCB component attachment. This is on her to-do list, but is not a high priority for now.
Cathode Board Discussion
- 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.
- Simon is continuing his work to specify the ASIC dynamic range. He has taken lots of data with the small scale prototype and has completed a series of simulations using GARFIELD to connect the cosmic ray and X-ray source data to what we expect with pions and protons. So far he has been able to use GARFIELD to reproduce the chamber data with cosmics and X-rays. He will now work to specify the dynamic range for cathode and anode and update the first draft of the associated report. This work is posted as GlueX-doc-1070. He will be giving a report soon to the Hall D group. - Fernando has suggested taking some data with a 90-10 Ar/CO2 mixture to ensure that we fully understand the 55-Fe data and to allow an easier connection with the CDC data. Simon will take this data shortly.
- DSC has collected all of the available FDC subsystem design drawings and placed them on the FDC website. The URL is: http://www.jlab.org/Hall-D/detector/fdc/drawings.html. Folks should go through the drawings and let DSC know what drawings and/or categories are missing for a complete design set. - Also folks should send DSC the latest design drawings where there have been changes to keep this web site up-to-date through the review season.
- 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.