Re: adc spectra for BCAL test run 2334

[Alex Dzierba <dzierba@indiana.edu>]

Hi Matt

Of course about the quantization- I am stupid!  Thanks for being gentle.

I am trying to track down the discrepancy between simulations and data for
energy deposition for ebeam < 300 MeV,  When I tried to use the geometric
mean for each module before summing for a layer I noticed the negative
pulse heights - and then started looking at adc spectra at the low end.
I latched on a red herring.

Thanks
Alex

At 10:17 AM -0400 6/13/07, Matthew Shepherd wrote:
>Sorry, forgot to finish my message:
>
>On Jun 13, 2007, at 10:08 AM, Matthew Shepherd wrote:
>
>>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..
>
>
>Your last plot further supports this -- you can see that when you 
>hit one of these heavily populated fractions, the average ADC value 
>is very near zero.  To me, this just means you are looking at ratios 
>of a couple count fluctuations about zero.  These ratios are 
>quantized and produce the peaks you see.
>
>-Matt


-- 
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Alex R. Dzierba
Chancellor's Professor of Physics (Emeritus)
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