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| − | Participants: Curtis, Mike, Naomi (CMU), Fernando, Eugene, Luke, Beni, Dave, Chris, Nick, Simon, Sergey and Lubomir (JLab). | + | Participants: Curtis, Naomi (CMU), Fernando, Eugene, Luke, Beni, Dave, Marc (Mcmullen), Chris, Nick, Simon, Sergey and Lubomir (JLab). |
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| − | == Electronics == | + | == CDC update == |
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| − | - Fernando studied the noise on the CDC and FDC together using two differential probes: see scope pictures linked in the agenda. First picture shows the noise levels in the two detectors are similar; FDC looks better but not by a lot. The second and third pictures show typical cosmic signals with correct timing. Last plot discussions - occasionally there are long tails in the CDC signals (~5 usec). | + | - Simon went trough half of the CDC layers: the deformations are not always in vertical direction, i.e. this may not be sagging. Need to make a map of all the measurements to make some conclusion. |
| − | The signals are still low enough (~100mV) so this is not a saturation effect (Fernando). Most likely it comes from ion tails (Lubomir), however it is not clear why it happens mostly in the CDC, is the ion-cancellation different in the two detectors?
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| − | - Nick: all "noise-reducing" elements from the CDC were removed. Tim is informed about that but needs to decide about the installation of an additional Al-foil target before inserting the target back. Nick replaced one LV module in the CDC; it was giving high current without any load. This is the second problematic LV module, the first one had different issue. | + | - Beni: CDC is working now with the new MFC (separated from the FDC) blending the same 50/50 mixture. Need to verify this with the CO2 sensor. |
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| − | - The PR for 100 spare pre-amps was approved. | + | - Measurements over weekend in mode 7. |
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| − | == CDC update ==
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| − | - Simon continues to study the tube deformations using beam data. So far he checked rings 1 to 7 and 13. Ring 7 (stereo) looks worse and there's a straw with more than 1mm deformation.
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| − | - Beni informed us that the Bryan's libraries on the hdcdcops account are the new ones, corresponding to the new f125 firmware.
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| | == FDC update == | | == FDC update == |
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| − | - Lubomir showed the change of the spring 2015 alignment offsets w,r.t. fall 2014 run (plot attached - black/red are x/y offsets for each cell given by the z-coordinate). The max deviations are for the first package +/- 200 microns. Most likely it has to do with the alignment procedure, that starts with package 3 then 4-2-1. The problem is however, that with the new alignments the resolutions in the spring runs are worse than in the fall run, like ~250 microns compared to ~200 microns in the fall. May have to do with the lower energies. | + | - Lubomir showed cathode resolution results from the spring run with two different ST+FCAL triggers: run 3137 "standard" trigger and run 3200 excluding 4 additional layers of blocks in the center. Also |
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| − | - Luke presented his latest results about the avalanche position studies with 55Fe. First plot shows the avalanche position in plane perpendicular to the wire - empty area around the wire is visible. Second plot: the two maximums in up/down direction vs gain - distance between them increases with decreasing the gain (no idea why!). Last plot is the same but for the maximums in left/right direction - no dependence on the gain as expected.
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| | == Engineering == | | == Engineering == |
