Revision as of 19:09, 10 January 2014

January 9, 2014 FDC meeting

Agenda

1. Installation [1],[2],[3],[4] (all)
2. Engineering (Bill)
3. Electronics (Chris, Nick)
4. Mini-DAQ [5] (Beni)
5. Other

Minutes

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

Installation

- One quadrant (top, left looking downstream) has been completely cabled at the detector side (see attached pictures), main work done by Mike Klopf (FEL) with the help of Shukui Zhan (FEL) and Lubomir. Now Nick, Robert (FEL) and Shukui are working on the connections at the electronics side. As of today Casey and Tina started cabling the right top side. Cabling procedure: starting with first package per quadrant, each 11 cables are grouped, total of three groups naturally following the pre-amp positions, and bundled together starting at the end of the mesh. In total there are 12 bundles that are then placed on the top cable tray and then the end is re-bundled according to the rack/crate positions.

- In between, while the cables were on the floor, Anatoly tested all the cables at the electronics end with a scope using the translator board which allows to test only the first 8 and the last 8 channels from the 24 in the connector. There were four bad channels (small signals) in packages 3 and 4, most likely conductive tape issues. There's one card with all the channels showing a long shoulder in the signal, we suspect the pre-amp.

- Since Friday last weak we switched the gas from Nitrogen to Ar/CO2 90/10. All the HV channels were OK till Tuesday evening when the same channels (that showed problems before Holidays) starting tripping from time to time. Right now one of the HV channels is really problematic tripping at >1400V (1600V is the nominal). Another four channels are tripping once per 8-24 hours. Certainly the trips are related to the gas. On Monday we expect to get the nominal gas mixture, 40/60.

Engineering

- Bill showed drawings (attached above) with the CDC bearings and attachment that require some space in between the two halves of the mesh. We wanted to put there three HV cables and a ground cable. Bill will get samples of these cable and look in place if they will fit there.

- Bill is trying to figure out the problem with the mass flow controller and contacted the Brooks company. The flow is about a factor of 2 lower than the nominal, but we are not sure how reliable the flow controller is.

- No results yet from the last survey done first week of December.

- Cathode scan: Bill will contact the company, expect a resolution of 100 microns which should be good enough because of the many measurements. Assumption is it will cost about few $k, Eugene agreed.

Electronics

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