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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