[d2n-analysis-talk] TDC/ADC entries

[Brad Sawatzky]

On Tue, 30 Mar 2010, posik at jlab.org wrote:

> So I am now looking at the re-timed multi-hit TDCs as cuts on the BB
> cerenkov ADCs and I just want to make sure that I understand this
> correctly. I checked all of my Ndata.variable_name that I get from my
> code with what I would get from using T->Draw("Ndata.variable_name")
> and the hits and entires I see in each variable agree. What I noticed
> is that when I go to plot say the cer TDCs, I loop over all hits on
> each PMT for each event. What I find is that the entires in the TDC
> histograms are greater than the number of events that I am replaying.
> Is this because for event i, it is triggering more than one TDC (ie if
> the particle were to strike the corners of four adjacent mirrors)?
> Below is a plot of the re-timed TDCs with some of the TDCs having more
> entries than events. This is from run 2060 and I replayed 100k events.

I'm not sure I follow.  You will certainly have more TDC hits than
triggers (events).  Individual particles often fire more than one
element in a given detector, and sometimes there is after-pulsing or
ringing.  On top of that, there are often more than one particle
interacting in the array during a single trigger (ie. backgrounds).

-- Brad

-- 
Brad Sawatzky, PhD <brads at jlab.org>  -<>-  Jefferson Lab / Hall C / C111
Ph: 757-269-5947  -<>-  Fax: 757-269-5235  -<>- Pager: brads-page at jlab.org
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