Minutes-8-7-2014

August 7, 2014 FDC+CDC meeting

Agenda

1. DAQ (Beni)
2. CDC status (Mike, Beni)
   • noise studies
3. FDC status interaction event reconstructed with cluster timing algorithm(Lubomir)
4. Electronics (Chris, Nick)
5. Engineering
   • Chiller
   • Cathode scan [1] (Luke)
6. Commissioning/calibration discussions (all)
7. Other

Instructions for Bluejeans meeting connection

FDC meeting ID: 290664653

Minutes

Participants: Sean (NU), Bill, Luke, Mike, Chris, Nick, Simon, Beni, Eugene, and Lubomir (JLab).

DAQ

- Beni: the synchronized run (CDC +BCAL) didn't work over the weekend. Something is wrong with the data, as if the the signals were not in the time window. Still, the DAQ was running over the weekend without crushing. Will try it again this weekend.

CDC update

- Beni: the noise was studied with modified HVB in which the resistors, that reduce the signal by 1/2, were removed. As result, both the noise and the signals increased by factor of 2. Beni will try also with the FDC pre-amp.

- Beni and Mike tried to improve the ground using: grounding braid connected to one HVB, Al foil covering the whole magnet opening. No improvements so far, but maybe one has to ground many more HVBs before you see any effect (Beni).

FDC update

- Lubomir was improving the tracking: significant advantage if one uses the timing of each ionization cluster (the positions of the maximums in the fADC data). The time should be the same for the upper, down strips and the wires. This allows to reconstruct multiple hits (ionization clusters) on the same wire or strip and separate tracks very close to each other, as demonstrated on the attached plot (shown are avalanche positions, no drift time correction yet).

Electronics

- Casey installed almost all CDC retainers (the retainer keeps the connector to the pre-amp in place).

Engineering

- Bill: the compressor will come today and will be replaced tomorrow. The chiller failed last Saturday due to compressor overheating, on Monday technicians from facilities found that the compressor has to be replaced. Bill: the most important question is why it failed and do we need spare chiller or parts for the long run. Eugene: during runs we don't want to wait a week for the chiller to be repaired. Let's first see if this failure was an exception, but in any case having a spare compressor (~$1k) will not be a problem.

- Bill: the water flow/quality is a suspect; rust found in the water filter. Therefore a flow meter for the chilled water was installed and Dave should be able to read it. According to Tom, we are going to change the water filter every month.