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| | = Minutes = | | = Minutes = |
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| − | Participants: Curtis, Naomi (CMU), Luke, Eugene, Dave, Chris, Nick, Simon, Mike, Beni, Fernando, and Lubomir (JLab). | + | Participants: Curtis, Naomi (CMU), Sean (NU), Luke, Dave, Chris, Mike, Simon, Beni, Fernando, and Lubomir (JLab). |
| − | | + | e difference in the pre-amp gains (factor of 4). |
| − | == Gas system ==
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| − | | + | |
| − | - Last Thursday after the FDC meeting Dave and Lubomir connected the power of the gas controls in the gas room to a UPS. When the power was restored the 4-20mA setting of the two masters were different (40mA as usual), but also the settings of one slave channel did change, that never happened before. Dave will see if he can read the settings and either restore them correctly, or issue an alarm. This has to be discussed also with Hovanes.
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| − | - On Saturday the switch on the CO2 bottles didn't work when one set of bottles got empty; it was supposed to switch to the full set of bottles. For one-two hours there was no CO2 flow into the FDC mixing tank, and 0.2l/m (instead of 0.9) was going into the CDC mixing tank. The bottom half of the CDC and 25% of the FDC channels tripped. Dave can implement an alarm, but everybody agrees some kind of a messaging system is needed, as well. Scott contacted the gas company to replace the switch. This switch was working before, and we have the same switch for the Argon bottles.
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| − | == DAQ ==
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| − | - Beni: The attempt to read synchronously the BCAL and the CDC failed. It's not clear why, the ROCs where receiving the data but then they got lost somewhere. Will try it again tomorrow.
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| − | - Beni: there's a problems with the relation between the pedestal positions and the DAC values in the fADC. The relation is different for the CDC and the FDC. For the CDC the pedestals are at ~500 and all the DAC values are set to 0x9000 (hex), and for the FDC the pedestals are at ~1000 but the DAC values are set all at 0x8000 (see raw data plots linked to item 4). Fernando explained this by the difference in the pre-amp gains (factor of 4).
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| | == CDC update == | | == CDC update == |
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| − | - Mike studied the noise in the CDC using raw fADC data. He applies a negative threshold (below the pedestal) and plots all the channels that pass the threshold as function of the sample number: there's clear correlations between the channels. The positions of these noisy channels is shown in the plot attached: mostly at the 6-9 o'clock sector when looking downstream. | + | - Mike made a report, linked above: the |
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| | == FDC update == | | == FDC update == |
