Difference between revisions of "Minutes-6-30-2011"
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== Engineering == | == Engineering == | ||
| − | + | - Based on the results with the first cell, it looks like we have some kind of frame deformation that Bill wants to investigate. The plan is to put the first cell package on a flat surface (like granite table) and measure the deformation of the frame. There were different ideas how to do it, but we expect deviation of 1-2mm which is measurable. Maybe related to that Casey noticed that the strong-back was sagging and asked for help people from the survey group. By the end of the meating we learned the results of their measurements: the strong-back is sagiing in the middle by 2mm. After meeting discussions: we will ask them to do also a survey of the first package in situ at 126 using the same tool. | |
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- FDC cabling scheme was discussed on a meeting this week and it was decided to build a mock-up. Bill gave us some details of the cable supports. We discussed the conduit material and if we need spare cables installed. Beni made a point that fixing connectors on the signal cables may require cutting the cables by 1ft to be in the flat part of the cable, as it happened already. That's why we need spare signal cables installed. Eugene regarding the number of the spare cables: we need to cover a sector for each package, say 4 or 8 per package; on the other hand we will have 42 conduits so it make sense to have 42 or 21 spare cables, something to be investigated with the mock-up. As for the HV/LV cables there are ways to fix/split the cables and such spares installed are not needed. | - FDC cabling scheme was discussed on a meeting this week and it was decided to build a mock-up. Bill gave us some details of the cable supports. We discussed the conduit material and if we need spare cables installed. Beni made a point that fixing connectors on the signal cables may require cutting the cables by 1ft to be in the flat part of the cable, as it happened already. That's why we need spare signal cables installed. Eugene regarding the number of the spare cables: we need to cover a sector for each package, say 4 or 8 per package; on the other hand we will have 42 conduits so it make sense to have 42 or 21 spare cables, something to be investigated with the mock-up. As for the HV/LV cables there are ways to fix/split the cables and such spares installed are not needed. | ||
Revision as of 17:41, 30 June 2011
June 30, 2011 FDC meeting
Contents
Agenda
- Production (Dave)
- Status Construction Tracking
- Second cell HV tests
- Radioactive source usage at Blue Crab
- Other
- Engineering (Bill)
- Package flatness measurements
- FDC cabling
- Other: gusset rings, lifting frame
- Electronics update (Fernando, Chris)
- Chamber testing at EEL126 (Beni, Lubomir)
- First cell status top/bottom asymmetry
- Future plans
- Other
Minutes
Participants: Eugene, Bill, Dave, Chris, Mark, Roger, Simon, Beni, and Lubomir.
Production
- Dave (see the Construction Tracking link above): cell#3: cathode type-2 needs three rigid-flexes (they were glued but Casey found they had solder bridges on the connectors), cathode type-1: the rigid-flexes to be glued. Since Monday we stopped working on the wire frame that was strung, due to possible tension problems discussed later. cell#4: first cathode tensioned, gluing foils for the second one. In addition techs are laminating wire frames, 6 ready so far. Beni asked if we cover the wires while soldering; not yet but we have the cover ready and will try it for the next wire plane. So far we have seen one solder ball on the wires, and Casey removed it.
- Lubomir on second cell HV tests: the cell is assembled as a package, now with lexan sheet on the top. The gas is runinng since Tuesday evening and since Wednesday we are conditioning the chamber. Today we are at 1800V/-500V with a current of 120-130nA for the whole chamber, which is at least 10 times smaller than the first cell. So, most likely the HV problems we had with the first cell are due to the ultrasonic cleaning in water (nobody was surprised).
- Thanks to Bert Manzlak and RadCon people there's a signficant progress with the source usage at Blue Crab. Keth Welch proposed using 25 micro-Curie 55Fe source which is bellow all regulation limits, but according to JLab rules they will most likely require creating RCA at Blue Crab and some additional restriction. Yesterday Bert and Vashek Vylet (RadCon) were at Blue Crab and didn't see any problems for having a source there. Now it's up to Rusty Sprouse to decide and see if there's something in the lease explicitly saying that we can't have a source there.
Engineering
- Based on the results with the first cell, it looks like we have some kind of frame deformation that Bill wants to investigate. The plan is to put the first cell package on a flat surface (like granite table) and measure the deformation of the frame. There were different ideas how to do it, but we expect deviation of 1-2mm which is measurable. Maybe related to that Casey noticed that the strong-back was sagging and asked for help people from the survey group. By the end of the meating we learned the results of their measurements: the strong-back is sagiing in the middle by 2mm. After meeting discussions: we will ask them to do also a survey of the first package in situ at 126 using the same tool.
