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| | == Production == | | == Production == |
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| − | - Dave: Last production package (#2) assembled! Redundant components: working on three more cathodes. Casey and Dave strung wire plane #31. Anatoly finished with the HV caps on #32, now also ready for stringing. | + | - Dave: Spare parts:about 70% are done (see the link above). Tina, Dave and Casey worked last Saturday to catch up with the foil gluing. |
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| − | - Lubomir: package #2 being flushed with gas, but showing somewhat lower pressure, 0.39-0.44 inch H20, than we had for the other packages, 0.50-0.54, at the same conditions (input flow of 220sccpm, and same position of the rotameter (~95 units) that takes the gas to the O2 analyzer. No gas leakage was found. Changing the manifold to the one used in package #1 didn't affect the pressure. | + | - Lubomir for package #2: all the channels were tested and are working fine, except noise was found on wire #37 of cell #2 (same wire that was replaced before). Same noise is visible on the top and bottom strips intersecting in one point close to the middle. On Monday we opened the package and Casey tried to clean that place and we closed the package with 5 cells. On Tuesday we found the source of the noise moved by 5cm and Casey did another attempt to clean it. On Wednesday |
| − | | + | we found again it moved by 2cm and decided to replace the wire. Casey and Dave replaced and checked the wire position and tension. Interestingly, the new wire was parallel to the old ones at <10 microns level at +/-20cm from the center. That means the strong-back didn't move since this old wire frame (#10) was strung. After the meeting we installed the last two cells of the package. |
| − | - Redundant components: we decided to produce six spare cells and build a full spare package. The package will not have pre-amp cards (need 132 and have about 20-30 spares) and therefore cooling tubes. We are not going to do the grounding, for that we prefer to have the cards in place to make sure we don't block the access to the connectors. Also we are not going to do the external HV wiring. Thus, if we need we can replace a package from the detector with the spare one, will use the cards and HV connectors together with the wires from the original package. We decided to deaden the wires with the larger diameter (7.8cm) so that we can replace any package. We have 7 wire planes to choose from to build six cells. We have also enough cathode frames except that one has to be converted from type 2 to type 1, i.e. milling the O-ring groove. Dave: we will need also two spacer rings and short HV cables. Eugene asked Dave to estimate the material and extra labor (about 5 manweeks) needed to build two additional cells.
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| | == Basis of Estimate for the FDC == | | == Basis of Estimate for the FDC == |
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| − | - Long discussion, line-by-line in the attached above spreadsheet. Important is that this BOE will result in a firm schedule (without any variance!) which in turn means new ETC, the last chance to ask for money! Eugene will need these estimates in first approximation by the beginning of the next week especially for the ETC. | + | - |
| − | We are asking to build two additional cells (Dave will estimate it) and for extending the partial tests of the packages that are already in the schedule (according to our interpretation) to full tests with all the electronics, cables, cooling system.
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| − | - Bill: for the survey part we need 0.4 man weeks (Jim Dahlberg's estimate); 4 weeks to procure the cooling system (Josh Foyles and Bill's estimate); 0.7 weeks to make a procedure and install the package spacers (in the "Complete FDC assembly" line).
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| − | - Consumables for 2013: the grounding clips and the AC in EEL126 ($6k) are already included in this activity. Dave has detailed estimate of $4k (attached above), but has to include the gas.
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| − | - Production of one cell and "Package Final Assembly and Testing" were estimated by Dave and Lubomir in the spreadsheet. Eugene interprets the "Package Final Assembly and Testing" as the partial tests done so far with two fADC125 and add new activities to be included in the ETC for all the packages for the full tests with all the electronics. The activity numbers will have to be added to the above spreadsheet.
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| − | - The installation part is still a gray area and we started discussing the procedures for cable installation and testing in the same time. The best would be to connect a sector from a package both with signal and LV cables, then to test them we apply LV and look at the noise from the pre-amps. We will have to come with some numbers by next week and have to discuss this items also with Tim, Tom, Fernando.
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| | == Engineering == | | == Engineering == |
![[1]](http://www.jlab.org/Hall-D/detector/fdc/drawings/TESTARR1.PNG){kind=link}
![[2]](http://www.jlab.org/Hall-D/detector/fdc/drawings/TESTARR2.PNG){kind=link}
![[3]](http://www.jlab.org/Hall-D/detector/fdc/drawings/TESTARR3.PNG){kind=link}