GEM Meeting, April 26, 2010
Contents
Analysis of Pedestals, runs taken until April 21, 2010 (Francesco)
Analyzed all the run listed in the Run List, until run 27402.
The pattern is stable for UVA GEM both chambers, while it looks having two different "states" in the INFN chambers. Within one hour the pedestals looks very stable (run 23355-23358) Pedestals calculated from a pedestal-run (27336) have no significant differences with respect to the values extracted from an on-beam run, but of course the noise is smaller. The pedestals show a "common-mode" shift on a 24-hour time-scale (comparison between runs 27355-27358 and run 27402)
Pedestal runs 27456 HV Off 27461 HV ON
File rich_ped_bottom_happexsp_27456-zero.dat and rich_ped_bottom-480.dat have no pedestal subraction on channel 0 ,239,240,479 of each planes
Pedestal run 27496 =
Analysis by Kiad
Copy of Kiad HALOG from Sunday
http://www.jlab.org/~adaq/halog/html/1004_archive/100425175140.html
Here are the plots for ADC vs Strip Number
HV Info
Run 27503-27507 CH0 3700 CH1 3700 CH2 4200 CH3 4200
Run 27508-27511 CH0 3800 CH1 3800 CH2 4300 CH3 4300
Run 27512-27513 CH0 3850 CH1 3850 CH2 4350 CH3 4350
File:Http://www.jlab.org/~adaq/halog/html/1004 archive/100425175140.1.gif
Meeting Summary
HV scan data needs to be looked at to study gain, probably strip-by-strip
Ole will add in gain-per-strip, code for filling in missing strips, pedestal suppression
Alex will continue to do source tests with the GEMs in the detector hut