Difference between revisions of "Minutes-12-4-2014"

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[http://www.jlab.org/Hall-D/detector/fdc/reports/FDC.pdf FDC fall run performance]
 
[http://www.jlab.org/Hall-D/detector/fdc/reports/FDC.pdf FDC fall run performance]
 
# Other: electronics, engineering  
 
# Other: electronics, engineering  
 
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= Minutes =
 
= Minutes =
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== CDC update ==
 
== CDC update ==
  
- Mike: CDC HV channels that were put on 100nA and 1uA scale both tripped during the photon beam alignment. Now both HV channels were switched to 10uA scale.
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- Most of the time we discussed the sagging of the pedestals at high rates as illustrated by the Mike's picture linked above: for the straws from the inner rings (numbering of the straws on x starts from the inner tubes) we see lower pedestal values. Proposed explanation (Lubomir): negative tails especially at high (saturated) amplitudes can't recover before the next hit. Fernando: it is possible, according to [http://argus.phys.uregina.ca/cgi-bin/private/DocDB/ShowDocument?docid=1364] there are negative tails after the pre-amp (examples of saturated signals not shown there) but it requires further studies together with the effects of the cable and fADC125 shaping. Fernando is going to study this on the bench.  
  
- Mike has a GUI that monitors the CDC rates online, using independent trigger-less readout of the crates. Mike is ready to work on a similar GUI for the FDC. 
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- Beni showed examples of fADC pulses where you often see saturated signals followed by long positive tail.  
  
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== FDC update ==
 
== FDC update ==
  
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- Vlad applied the reconstructed gain coefficients of the third package to the data from the EEL: these 3% (R.M.S.) corrections result in improvement of the strip resolution from 150 microns to 140 microns.  
 
- Vlad applied the reconstructed gain coefficients of the third package to the data from the EEL: these 3% (R.M.S.) corrections result in improvement of the strip resolution from 150 microns to 140 microns.  
 
== Commissioning ==
 
 
- Lubomir has a working plugin for the FDC online monitoring that works with the latest f125 data format.
 
 
- Simon (answering Eugene's question) about the CDC alignment: no improvement in the resolution so far, limited by the statistics and the fact that the cosmic trigger selects tracks at one side of the detector. Expect better results with BCAL trigger and more statistics.
 
  
 
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Revision as of 13:30, 8 December 2014

December 4, 2014 FDC+CDC meeting

Connection

  1. Instructions for Bluejeans meeting connection
  2. FDC meeting ID: 290664653
  3. To join via a Web Browser, go to the page [1] https://bluejeans.com/290664653.

Agenda

  1. CDC analysis update (Beni, Mike)
    1. Pedestal sagging
    2. CDCpedestals.root pedestals as function of time.
  2. FDC analysis update (Lubomir, Vlad)

FDC fall run performance

  1. Other: electronics, engineering

Minutes

Participants: Sean (NU), Curtis, Naomi (CMU) Beni, Mike, Cody, Dave, Nick, Chris, Simon, Fernando, Vlad, and Lubomir (JLab).

CDC update

- Most of the time we discussed the sagging of the pedestals at high rates as illustrated by the Mike's picture linked above: for the straws from the inner rings (numbering of the straws on x starts from the inner tubes) we see lower pedestal values. Proposed explanation (Lubomir): negative tails especially at high (saturated) amplitudes can't recover before the next hit. Fernando: it is possible, according to [2] there are negative tails after the pre-amp (examples of saturated signals not shown there) but it requires further studies together with the effects of the cable and fADC125 shaping. Fernando is going to study this on the bench.

- Beni showed examples of fADC pulses where you often see saturated signals followed by long positive tail.