Revision as of 12:53, 17 January 2014

January 16, 2014 FDC meeting

Agenda

1. Installation [1],[2],[3],[4] (all)
2. Engineering (Bill)
   • Cooling system status
   • Gas system status
   • Other: FDC survey, cathode scan
3. Electronics (Chris, Nick)
4. Mini-DAQ results [5] (Beni)
5. Other

Minutes

Participants: Eugene, Fernando, Dave, Nick, Chris, Simon, Bill, Beni, and Lubomir.

Installation

- The top two quadrants were cabled (see first three pictures attached); Mike Klopf was working till his last minute at JLab, to arrange the cables nice and uniform (first picture). Nick is almost done with routing the second quadrant to the electronics. Casey and Tina are working now on the bottom right quadrant and have cabled already two packages (second picture).

- Discussions about the routing of the LV cables. They all have to run the the left side (looking downstream) and it is not clear yet how they will be attached to the face of the magnet in their final position. Therefore, Tom prefers the disconnect them from the LV panel during insertion and then route them again to the panel. Fernando, Bill and other disagree; Beni showed on a drawing how to route the bottom half in order to avoid disconnection from the panel. Lubomir discussed if the extra length of the big bundle at the top right cable tray is enough for the FDC insertion (third picture).

- On Monday we changed the gas to 40/60 Ar/CO2 pre-mixed bottle. The flow was initially increased from 400 to 1000 sccpm (using another mass flow controller with 6000 sccpm range and another rotameter), but at this point the bubblers stopped bubbling: the same old story and we suspect again that somehow gas channels with high impedance are created, making connection from the bubble meniscus to the air. Finally the flow was set to 800 sccpm (200 sccpm per package) so that the bubblers can work.

- Since Wednesday nominal HV, +2100/-500V, has been set on all channels except one (fourth picture showing its current) with +2000/-500V and there were no trips for more than 24 hours. After the meeting that channel was also set to the nominal HV and is stable: all the HV channels are now operational with the nominal gas mixture.

Engineering