[d2n-analysis-talk] BigBite Shower Calibration Overview

[Brad Sawatzky]

Looks pretty good.

A 'Variable summary table' (var name, brief description) would be
convenient for a quick lookup (no need to change the body text).

In para 2 the reason for the different gain setting is that the
preshower sees less signal than the shower for physics events.  Both the
shower and pre-shower blocks see the same deposited energy for cosmics.
It's not clear from the last sentence which variable maps to what
sub-detector (and I think there is a typo in the variable names too).

Regarding para 3, 2nd last sentence.  There was never any need to divide
the pre-shower ADC values by 2 in the calibration script -- it was, at
best, a convenience.  I would change the sentence to something like
this:
  Since the pre-shower HVs were set to align the cosmic minimum
  ionization peak at channel 240 (vs. channel 120 for the shower
  blocks), it was convenient to divide the preshower ADC values by two
  in the sum used in the calibration.  The factor of two means that the
  calibration coefficients for all blocks (preshower and shower) should
  be roughly equal.

I think it could use a brief discussion of how (ie. which) blocks are
summed to form clusters.

-- Brad

On Fri, 04 Nov 2011, posik at jlab.org wrote:

> Hi all,
> 
>    I have just posted to the d2n wiki a quick overview of the shower
> calibration for BigBite during the d2n experiment. You can find the
> write up here:
> 
> https://hallaweb.jlab.org/wiki/images/4/47/Shower_calib_overview.pdf
> 
> This is intended to be a brief and hopefully clear description of our
> calibration procedure. In the write up you will find the definitions of
> some of the variables that show up in the ROOT files that go into making
> the calorimeter energy, as well as an explanation for the factor of 1/2
> that gets put on the pre-shower energy.
> 
>  I tried to be as clear as I could, so if something is unclear please let
> me know so that I could try to make it clearer in the write up.
> 
> Thanks
> Matt
> 
-- 
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
The most exciting phrase to hear in science, the one that heralds new
  discoveries, is not "Eureka!" but "That's funny..."   -- Isaac Asimov