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Re: calorimeter document
I will make the Figure change you suggest
Cheers
Alex
At 10:07 PM -0500 2/6/08, Elke-Caroline Aschenauer wrote:
>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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>,&&&&&&&&&&; Suite 8 Hampton, VA 23664 -
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--
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Alex R. Dzierba
Chancellor's Professor of Physics (Emeritus)
Department of Physics / Indiana U / Bloomington IN 47405 / 812-855-9421
JLab Visiting Fellow
Jefferson Lab / 12000 Jefferson Ave / Newport News, VA 23606 / 757-269-7577
Home Phone: 812-825-4063 Cell: 812-327-1881 Fax: 866-541-1263
http://www.dzre.com/alex
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