July 17, 2013 Tracking CDC/FDC
Meeting Time and Place
Wednesday July 17, 2013 at 11:00am At Jefferson Lab, the meeting will be held in F326
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Present: Curtis, Naomi, Simon, David, Elton, Lubomir, Cody
- FDC Update
- The four FDC packages were put together. Three spacers were installed in between each with three fiberglass rods defining the distance between the packages. For two of the spacers additional threaded rod was added to clear a small gap between the spacer and the gusset ring.
- The test of the third package with full electronics was finished. The main issue was with the pre-amp/daughter card connections. Most were fixed by re-seating the pre-amps or bending the cooling tubes. For one pre-amp with ~10 bad channels we had to insert a thin g10 plate between the wire and cathode frame thus applying pressure on the conductive tape. This fixed all the channels but it means at least in this case we have problems with the conductive tape.
- CDC Update
- The cooling rings are complete, Amy & Gary hooked up a 6-way manifold and verified that a gentle breeze comes from the all holes including those furthest from the inlet on the biggest ring. Gary is going to order a 9-way manifold. We need to talk to Elliott about a flowmeter/control unit.
- Beni's VXS crate arrived. Naomi got the old flash working in it but not the new one, it doesn't recognise the new flash yet. This is using Bryan's new library. Cody came to the conclusion that the firmware needs to be reloaded so that will be next.
- Data formats
- Following email discussion, the starting point for the meeting was the format options d and e in David's slides.
- We would like to have different data types (readout data formats) available, at least two, one being the run mode with the minimum information needed for event readout, and another being a raw mode which would contain the run mode info as well as full precision raw sample data which would include pedestal. This would be very useful for any further development of the FPGA algorithms.
- We would like to do dedicated calibration runs every so often, using the raw mode readout.
- The FPGA code version number should be included, probably in the block header.
- The CDC and FDC need not use the exact same data format if there is reason to differ.
- The CDC algorithm will perform pedestal subtraction on an event by event basis using pedestal immediately before the hit. Lubomir will think about pedestal and common noise subtraction for the FDC.
- Pedestal data (but not necessarily full precision) should be included with event readout to identify if the event is on the tail of a previous hit, in which case the pedestal could be very high and falling rapidly, to indicate the overflow amplitude, and also to enable alarms to be triggered if the pedestal is outside a certain range.
- Naomi will send a spec to David for the CDC.