2005 BSMD zero-suppressed ADCs

Background:  Ahmed posted some studies of the BSMD in Run 7 indicating that the ADC dynamic range is limited.  Pibero and Willie showed a dramatic band structure of the raw ADCs in the 2006 pp, and people wondered how far back this structure existed.  Here is the data from 2005.

What's being plotted:

  • 2005 pp data
  • zero-suppressed at (adc-ped) < 1.5*rms
  • NOT pedestal-subtracted
  • restricted to status==1
  • ~4000 files from throughout Run 5
  • strip softId on x-axis -- each plot is another 1000 strips

And finally, here's a projection of strips 1-150:

Clearly, the band structure was there as well.

Update:  Renee mentioned that 4500-4600 look a little cleaner than the rest.  Here are projections for 4500-4590 and 4500-4650.  The band structure doesn't disappear, but the slope of the exponential fall-off is steeper so fewer counts end up in the screwy 500+ regime.  Here are the results of fits to the region 100 - 150:

0001-0150:  slope = -0.0105
4500-4650:  slope = -0.0130
4500-4590:  slope = -0.0150

See also:  2005 BSMD zero-suppressed ADCs (minbias triggers)