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Re: adc spectra for BCAL test run 2334
Alex,
Isn't this just the behavior of cells with very low energy?
In the first plot one sees a peak at zero. The pedestal has some
finite width so subtracting the mean of the pedestal will produce
fluctuations below zero.
On to the ratio plots: you will always have modules that have very
little energy deposition and therefore very low numbers of ADC counts
on each end. For example if you have modules whose ADC counts are
drawn from the spectra on the first slide I can believe there are
many such modules with
north : south
1:1
1:2
2:2
2:3
3:2
4:2
5:2
and so forth. It looks like all of these common low count
"fractions" get populated in your histogram. I see small peaks at
3/2 5/2, 7/2, 1/2, 1/4, 3/4, 2/3, etc..
In fact, I would suspect that you might have negative north south
ratios that are mainly populating these "quantized" values in cases
where the pedestal subtracted data fluctuates below zero.
-Matt