Re: BCAL and KLOE

[Elton Smith <elton@jlab.org>]

HI Alex,

I assume their number of 1p.e./MeV is relative to incident photon energy.
Therefore, our number should be 25 p.e. for mip/3.8 cm = 0.5 (scint
frac)*3.8 *2 MeV/cm = 3.8 MeV in scintillator, but this is equivalent to
3.8MeV/sampling fraction = 3.8/0.12 = 32 MeV / 25 p.e. or 0.8 p.e./MeV of
equivalent energy.

Cheers, Elton.




Elton Smith
Jefferson Lab MS 12H5
12000 Jefferson Ave
Suite # 16
Newport News, VA 23606
elton@jlab.org
(757) 269-7625

On Thu, 15 Nov 2007, Alex Dzierba wrote:

> Hi All
>
> See the attached from a talk given by Paolo Gauzzi (Rome) on the
> KLOE calorimeter.  Note the p.e./MeV yield based on their cosmics
> data -- their 1 p.e./MeV for the center of a 4 m module whereas
> our estimates for BCAL are 23 p.e./MeV but we measure about
> 8 p.e./MeV.  Also - they claim 32 MeV deposition for a MIP.
> Based on their geometry I would have expected about 24 MeV
> assuming they are 15Xo thick where their Xo=1.6 cm and the
> matrix is 50% scintillator.  Comments from UR?
>
> Gauzzi's slide also indicates they go down to 25 MeV?  In their
> NIM paper they claim 99% efficiency for photons above 80 MeV
> and then it drops.  See the attached jpeg
>
> Cheers
> Alex
> --
> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> Alex R. Dzierba
> Chancellor's Professor of Physics (Emeritus)
> Department of Physics / Indiana U / Bloomington IN 47405 / 812-855-9421
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