Difference between revisions of "Minutes-2-2-2012"
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== Production == | == Production == | ||
| − | - Dave: wire boards #20 and #21 ready waiting just for electroplating. | + | - Dave: wire boards #20 and #21 ready waiting just for electroplating. #22 ready for tension measurements. Problem found on #23 (before stringing!): a signal trace (#96) has short to ground most likely in the via or on the trace on the back side of the board. The plan is first to drill the via and confirm the problem is there. Then we will make on opening in the frame to access the trace on the back side of the board, fortunately there's Rohacell on the back of the via, not solid G10. Then we will solder insulated wire to make the connection. Cathode #33 was glued to the frame with some offset of ~3mm at most. One frame hole covers a trace on the connector; it can be fixed in principal but also the offset is not acceptable (Simon). So we have enough spare material to replace this cathode and will use it only if needed. Wire frame #13 (with the capacitor traces de-laminated) was inspected by EEFAB people. They said it can be fixed in two days, however later they claimed they need a $26K machine for that and want to share the costs; Dave will negotiate with them. |
| − | - | + | - Another sample using the original electroplating recipe was made with the hope the surface will be smoother. Waiting for the microscope pictures from Olga to make a decision whether we can continue with the wire deadening: two wire planes ready and waiting for this decision. |
| − | = First package testing | + | - Second package was put in the rail frame. We discussed that one of the bearings must be fixed (no gap), right now both are loose, so has to be replaced later. Chris: pre-amps for four cells ready but ran out of some parts then Cody has to test them. After that we will install them on the package together with the cooling tubes. |
| + | |||
| + | = First package testing = | ||
| − | - | + | - The problems we had before with the HV were understood and fixed after swapping the Ar and CO2 in the gas system. Right now we have Ar/CO2 50/50 and all the channels up at +1920/-500V operating without trips already 24 hours. The gain, as roughly estimated with a source, is ~10^4 and the package is ready for the tests. Normally we work at 4-8 10^4, so later we will increase the HV by 100-150V. |
| + | |||
| + | - Beni pointed out that three of the HV channels (one + and two -) trip at 1V even after they have been disconnected from the chamber. Problem might be at the cable/connectors or in the module. Beni will | ||
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| + | - Gas problem: the gas tightness is worse than it was at Blue Crab. Now the flow rate is 280ccpm and pressure inside ~40Pa. Most likely there's leakage at the gas inlets that has to be fixed later. Bill: for the next packages we should be more careful handling the tubes connected to the inlets. | ||
- Gas problem: initially it was bubbling at >220ccpm (compared to 40-50ccpm at Blue Crab), but there was no obvious gas leakage except some (1x10^-4 on the leakage detector scale) at the southern side where the input gas connectors were. Today the input and output connectors were swapped and the problem almost disappeared, which indicates the leakage was somewhere at gas connectors or close that to in the chamber. Has to be found and fixed later! | - Gas problem: initially it was bubbling at >220ccpm (compared to 40-50ccpm at Blue Crab), but there was no obvious gas leakage except some (1x10^-4 on the leakage detector scale) at the southern side where the input gas connectors were. Today the input and output connectors were swapped and the problem almost disappeared, which indicates the leakage was somewhere at gas connectors or close that to in the chamber. Has to be found and fixed later! | ||
Revision as of 17:21, 2 February 2012
February 2, 2012 FDC meeting
Agenda
- Production update Construction Tracking (Dave)
- Third package status
- Electroplating results
- Plans for the second package
- First package testing (Lubomir, Beni)
- Engineering update (Bill)
- Cooling system
- Other: HV connector position
- Electronics update (Chris)
- Other: once more naming convention
