sPHENIX EMCal discussion

[Craig Woody <woody AT bnl.gov>]

THP was supposed to have a tracking document for every module they 
produced. They just didn't do this for the last modules they produced.

On 2/29/2016 10:36 AM, Sickles, Anne M wrote:
> Hi John & Don,
>
> I think it would be interesting to try what John suggests for the prototype 
> and its simulations (since we have the density by module and we’ll know the 
> module location).   I know Sean and Craig have tried to put the best modules 
> toward the center of the prototype; this will minimize the density variations 
> at the core of showers so it may be that this isn’t a large effect right now. 
>  Jin, is it possible to vary the module density within the current simulation 
> framework?
>
> As to the module tracking, I agree with Don.  We were surprised to find that 
> THP hadn’t kept track of this kind of information at production time and we 
> will need it on all future module productions.  For the Illinois modules, we 
> have set up a google spreadsheet which works fine for the number of modules 
> we’ve made currently, but we’ll need something different as the number of 
> modules increases.
>
> Anne
>
>
> > On Feb 29, 2016, at 8:56 AM, dlynch AT bnl.gov wrote:
> >
> > Hi all,
> >
> > My 2 cents, we should be able to trace the THP modules back to their 
> > production. If THP is not already doing so, they should be tracking each 
> > module with a route card so that variations in materials, procedures, 
> > assembly techniques, and personnel can be tracked. This is basic QA and not 
> > just a good idea but generally a requirement in the QA section of BNL 
> > Purchase Orders.
> >
> >
> > -Don
> >
> > From: <sphenix-emcal-l-bounces AT lists.bnl.gov> on behalf of "Sickles, Anne M" 
> > <sickles AT illinois.edu>
> > Date: Friday, February 26, 2016 at 8:16 PM
> > To: Gabor David <david AT bnl.gov>
> > Cc: "sphenix-emcal-l AT lists.bnl.gov" <sphenix-emcal-l AT lists.bnl.gov>
> > Subject: Re: [Sphenix-emcal-l] Density plot
> >
> > Hi Dave, John & Gabor,
> >
> > The Illinois modules are numbered according to the production sequence so, yes, 
> > in general we are getting higher density with time.  However there are a couple 
> > of features.  Between module 6 & 7 there was a change in the filling 
> > procedure for the tungsten and you can see a corresponding increase in density.  
> > Additionally the final eight Illinois modules were produced with a different 
> > batch of tungsten powder from the prior modules and a slightly different mold.  
> > These modules were all produced this week under essentially identical conditions 
> > and thus I think the observed density variation is inherent in the (current) 
> > procedure.  The effect of the tungsten powder batch is something we are looking 
> > into in more detail; at this point we can only say that not all tungsten powder 
> > is the same…
> >
> > For the THP modules the numbers don’t mean anything about the production 
> > since the numbers were assigned in Illinois rather than at THP at production 
> > time.  The density variation is a point of concern, but I don’t have a 
> > quantitative number of the size of density variation we can tolerate.  
> > Obviously we can take steps to correct for it or model it with simulation, 
> > but we also need to build a density range into our QA criteria for the 
> > modules themselves.  That is something I hope to understand better with the 
> > test beam.
> >
> > Best,
> > Anne
> >
> > > On Feb 26, 2016, at 5:29 PM, Gabor David <david AT bnl.gov> wrote:
> > >
> > > On Fri, 26 Feb 2016, Lajoie, John G [PHYSA] wrote:
> > >
> > > Hi, John,
> > >
> > > > Hi Vera,
> > > >      Very nice plot!
> > > >      The THP points in particular had me wondering if there is a limit to the
> > > > variation of the density that you can tolerate?  I would expect that a
> > > > module-to-module variation in the density (of the absorber) would lead to a
> > > > variation in the effective sampling fraction, which could degrade the
> > > > effective energy resolution.  I suppose if you knew the density of each
> > > > module you could make a correction?
> > > wild guess: yes, and two different ways.
> > > 1/ have the same density in each module in the simulation,
> > > but at the end correct the visible signal in each tower (such a
> > > "calibration of the simulation output" is not unheard of, actually
> > > in some sense we are doing it even now)
> > > 2/ get different densities for different modules in GEANT4
> > > (just kidding; nightmare!)
> > >
> > > Maybe a first good question to ask would be to compare
> > > the simulated response in two modules with densities corresponding
> > > to the two ends of the current density distribution.
> > >
> > > 2 cents :-)
> > >
> > > Gabor
> > >
> > > > John
> > > > On 2/26/2016 4:24 PM, Loggins, Vera wrote:
> > > >       Hi all,
> > > > I just wanted to share the density plot vs. module number that we have
> > > > at UIUC.  I have plotted this along with THP's numbers.
> > > > Have a good weekend,
> > > > Vera
> > > > --
> > > > John Lajoie
> > > > Professor of Physics
> > > > Iowa State University
> > > >   
> > > > (515) 294-6952
> > > > lajoie AT iastate.edu
> > > > Facebook LinkedIn
> > > > Contact me: Skype john.lajoie
> > > --
> > > Gabor David  (david AT bnl.gov)
> > > Brookhaven National Laboratory
> > > Physics Department, Bldg 510/c
> > > UPTON NY 11973
> > > Tel: (631)344-3016
> > > FAX: (631)344-3253_______________________________________________
> > > Sphenix-emcal-l mailing list
> > > Sphenix-emcal-l AT lists.bnl.gov
> > > https://lists.bnl.gov/mailman/listinfo/sphenix-emcal-l
> > --------------------------------------------------------------
> > Anne Sickles
> > Assistant Professor, Department of Physics
> > University of Illinois at Urbana-Champaign
> > --------------------------------------------------------------
> >
> >
> >
> >
> >
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