ECAL0 for GPD Measurements at COMPASS:

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ECAL0 for GPD Measurements at COMPASS current
status ECAL0 Team, JINR, DUBNA
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MC studies on p0 background

The MC samples were prepared according to the
settings from COMPASS Notes 2006-11 and
2007-6 Set MC samples with DVCS photons only
(no cut on t ) Set MC samples with photons
from p0 decays SIDIS events only Ratio of
cross section between DVCS and SIDIS is taken to
be about 15
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MC studies on p0 background

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Tests of the ECAL0 modules
The modules from town Vladimir are under testing
now The distribution of photoelectrons for
cosmic muons is given below
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Tests of the ECAL0 modules
The distribution of the light in scintillator
plate 12x12 cm2
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Tests of the ECAL0 modules
LFS crystal 2x2 x12 mm3 Source 137CS 600
KeV PM and AMPD are compared
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Temperature Control System for ECAL0 (tests)
Interval 10 -18 deg. Stability
0.25 deg. Power Max 13 W
Max 2.0 A for 6 V
0.1 A for 12 V Tested volume 5x5x7 cm3 The
Temperature Control System is based on the TEC
(Thermoelectric Cooler) with size 4x4 cm2
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ECAL0 View
Possible view of ECAL0 sizes 360x360 cm2
with central hole 120x120 cm2 lenght
25-30 cm modules 800 with
size 12x12 cm2 (shashlyk) AMPDs 9300
for inner part 16 AMPDs per module for outer
part 9 AMPDs per module