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Re: calorimeter document
On Wed, 6 Feb 2008, Elke-Caroline Aschenauer wrote:
Ciao Ciao,
3 more things which came to my mind last night.
2. BCAL + Appendix
table 1 misses the lead sheet thickness
4. simulation
does the new photon detection threshold not influence the occupancy in the
fcal.
also I think we should mention explicitly what photon energy range was
taken for the MC.
bye elke
> Date: Wed, 6 Feb 2008 22:07:06 -0500 (EST)
> From: Elke-Caroline Aschenauer <elke@jlab.org>
> To: halld-cal@jlab.org
> Cc: zorn@jlab.org, Timothy Whitlatch <whitey@jlab.org>
> Subject: calorimeter document
>
>
> Dear all,
>
> I have not read every line, but I would like to share some high level
> observations with you.
>
> Cheers elke
>
>
> 1. Introduction.
>
> Alex i think it would be nice if possible to replace the colored plots in
> fig 2 with the ones you did today for your talk with the bar at the side
> showing the relations between the colors.
>
> 2. BCAL + Appendix
>
> I see no mentioning of electronics at all. Neither TDC nor FADC.
> Should there not be at least a small paragraph on what requirements on
> resolution and dynamic range we have to the electronics?
> No mentioning of assembly or so, this is different to the FCal section.
> It is okay to do this, but looks a bit strange. We could refer to the
> pre-brief material drawings on the BCal assembly.
>
>
> SiPMTs:
> =======
>
> what ever we write the test should not immediately suggest to the reader
> that we are still far away from a final solution especially this is a 100%
> design review. This opinion can be easily created reading this some of the
> sections from the report testing this first arrays. I think we have to
> check this again carefully.
> Carl, some of the remarks made in your talk by Elton, George and me should
> maybe incorporated in the write-up. I think the plots from Elton showing the
> trade off between dark current and pde to reach the desired low energy
> threshold should appear somewhere.
>
>
> One more remark of caution here. Regina and JLab have a agreement of
> disclosure with Sensl are we allowed to show all we are showing in this
> report taking into account this disclosure agreement? Just something to
> think about.
>
> 3. Fcal:
>
> okay here I don't know the version on the www is the last one. but don't
> we want to show rates for the inner blocks? Maybe even a plot showing the
> difference between the old FDC material and the new one.
>
> For the FCAl we mention electronics and holding structures.
>
> 4. Simulation.
>
> section 2.1: does noise not also influence your lower photon threshold.
> It is not mention not a super big deal but important. In the
> worst case say just say still under study.
>
> section 2.2: just a remark the current SiPMTs would not allow a
> 100ns gate width. Actually if the plots from Elton on pde
> vs dark rate appear in the document, it would be good to check
> the current thresholds are close to the numbers from
> this study. I think they are.
>
> section 3.4
>
> I think it would be helpful to label the peaks to show which one comes
> from which part in the detector. I like a lot the plots on photon
> conversion beni does always z vs r. they give an idea where the problem
> areas are. I would include one in addition to figure 10.
>
> section 3:
>
> I think it would be really nice to have a summary table showing the energy
> and time resolution you get fro the simulations of both calorimeters and
> compare it with the once we get from beam and cosmic tests.
>
> section 4:
>
> fig 12 and 13 show the combination of all photons in an event to either
> give a pi0 or a eta. You show also the chi^2 for the fit confidence level.
> Does the result for the chi^2 not depend strongly on your assumptions for
> the constrained mass fit. I think it would be good to list which
> constrains have been assumed and what happens if you vary them.
>
> One more question how are this plots looking if you just assume that the
> single photon energies are the same in some error.
>
> Is it obvious why the background shapes for the different pi0 and eta
> combinations (FCAL, FCAL+BCAL, and BCAL) change?
>
> section 4.2
> I have to ask unfortunately the same question again I asked already during
> the collab meeting.
> Pythia generates everything which is can be produced by a 9 GeV photon.
> It has no signal events in. Now you run your generator which is able to
> generate exotic waves, with all their special properties.
> You mix this to event classes with some ration like 10:1 Pythia to exotic
> or 1:1 or ....
> than you run your analysis and see you find your exotic wave. If yes
> wonderful if not you can set a limit on your sensitivity.
>
> Why are you allowed to remove signal like events from the Pythia
> background. In real life / data you can not tell what are signal events
> and what comes from QCD photo-production (I don't want to say exotics
> are not QCD).
>
> The section describing the eta-pi0 analysis on page 18
> bottom and page 19 is a bit dense to really follow in detail. As it is
> a very important analysis a bit more explanation would be helpful. I can
> explain in more detail on the phone or ... what i think would be needed.
>
>
>
>
>
>
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> | `, Elke-Caroline Aschenauer =
> \,_ `-/ -
> ,&&&&&V Jefferson Lab +
> ,&&&&&&&&: HALL-D 12C / F381 121-A Atlantic Avenue =
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> | | ;--' | Mail: elke@jlab.org Mobil: 001-757-256-5224 -
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( `,_' )+=-+=-+=-+=-+=-+=-+=-+=-+=-+=-+=-+=-+=-+=-+=-+=-+=
) `\ -
/ '. | +
| `, Elke-Caroline Aschenauer =
\,_ `-/ -
,&&&&&V Jefferson Lab +
,&&&&&&&&: HALL-D 12C / F381 121-A Atlantic Avenue =
,&&&&&&&&&&; Suite 8 Hampton, VA 23664 -
| |&&&&&&&;\ 12000 Jefferson Ave +
| | :_) _ Newport News, VA 23606 Tel.: 001-757-224-1216 =
| | ;--' | Mail: elke@jlab.org Mobil: 001-757-256-5224 -
'--' `-.--. | +
\_ | |---' Tel.: 001-757-269-5352 =
`-._\__/ Fax.: 001-757-269-6331 -
+=-+=-+=-+=-+=-+=-+=-+=-+=-+=-+=-+=-+=-+=-+=-+=-+=-+=-+=-+=-+