Meeting-3-8-2018

March 8, 2018 Drift Chamber meeting

Connection

1. Instructions for Bluejeans meeting connection
2. Meeting ID: 290664653

Headline text

1. To join via a Web Browser, go to the page [1] https://bluejeans.com/290664653.

Agenda

1. Current analysis/issues:
   • CDC
   • CDC events again
2. fADC125
3. Other

Minutes

Participants: Naomi (CMU) Eugene, Beni, Alex B., Simon, Alex A., Thomas, and Lubomir (JLab).

Current analysis/issues

- Naomi analyzed the runs from the CDC threshold scan (presentation attached). The number of hits certainly depends on the threshold, mostly pronounced between 90 and 110 (f125 units). The percentage of hits that participate in the tracks (about 30% ) also goes down with the threshold, however this change is relatively small in the 90-140 threshold range.

- The interesting feature Naomi found is that there's a class of events with low amplitudes with a peak in time that is 20ns later than the peak in the drift time for the good hits. Some of these hits end up as part of the tracks, especially at low thresholds, and their theta/z distributions look similar to the ones of the good hits. We had long discussions about the origin of these hits without any conclusion: cross-talk, some kind of e.m.background, electronic noise, reflection at the open end of the straw ... Important is to look at the wave forms of these events (Eugene). Pure electronic noise we can study on the channels that are disconnected from the straws.

- Lubomir showed some CDC events from the raw mode run, that were shown before by Sergey, just adding info about the drift time in the x/y plots (attached).