Minutes-12-4-2014

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.