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Construction and Assembly of the first Barrel Slice for the
Electromagnetic Calorimeter of the PANDA Experiment
K.T. Brinkmann1, M.Moritz1 ,A. Ryazantsev2, P. Wieczorek5, B. Wohlfahrt1 and H.-G. Zaunick1 for the PANDA-Collaboration
12nd Physics Institute, Justus-Liebig-University Giessen, Germany 2IHEP Protvino, Protvino, Russia
3GSI Helmholtzzentrum für Schwerionenforschung, Darmstadt, Germany
Corresponding authors:
Markus Moritz, markus.moritz@exp2.physik.uni-giessen.de
Hans-Georg Zaunick, hans-georg.zaunick@exp2.physik.uni-giessen.de
Heinrich-Buff-Ring 16, 35392 Gießen, Germany
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The PANDA electromagnetic calorimeter (EMC) and the recent prototypes
Prototypes:
• Small sections of one barrel slice
The readout concept of the EMC
Assembly of single Detectors
• Placement of 40 crystals in a type 7 alveole block
2 LAAPDs (7x14 mm2) read out simultaneously by one APFEL ASIC
• Two channels with different gains for each LAAPD
• Dynamic range of 10000 (1 MeV to 12 GeV)
• Programmable amplification of 16/32
• High rate capability (up to 500 kHz)
• Low power consumption: 55 mW/ch
Conclusions
and Outlook
Energy resolution (3x3 submatrix)
Feature extraction Line shapes
• Energy = maximum - pedestal
• Assembly of first slice segment of the PANDA Barrel EMC nearly finished
• Mass production established for crystal detectors and modular detector blocks
• Calibration and energy resolution extensively studied with close-to-final prototype PROTO120
• A submatrix of depolished (uniformized light yield) crystals was tested and improvement for energy resolution demonstrated
• The next steps are: installation of insulation, cooling and test measurements
Expected Performance of the Calorimeter (TDR requirements and earlier prototype setups)
APD response
Results obtained with final PROTO120
prototype
In agreement with TDR requirement
• Roughening of one side
...surface by controlled
...polishing with fixed grain size
Light collection and Non-UniFormity (NUF)
Impact on energy resolution
The planned PANDA detector @ FAIR
Target EMC barrel part of the EMC
PROTO60
PROTO120
Barrel EMC:
• 15552 PbWO4 crystals (length: 20 cm ~ 22 X0)
• 13 crystal types (different degree of tapering)
• Type 1: most tapered, type 13: least tapered
• Operation temperature: -25 °C
one slice
SADC:
• 50/125 MHz
• No additional
timing branch
Glueing station
Linear energy response
APD pre-assembly treatment
• Both APDs show a linear
correlated response in the
region of the dynamic range
Reduction of NUF improves the energy resolution
. at higher energies
trace
recorded
by SADC
Single crystal noise level: 0.9 – 1.0 MeV
Single crystal threshold: 2.8 – 3.0 MeV
Single crystal
light collection
. is homogenized
Cluster sum
Optical fibers
Preamplifiers Alveole inserts
Crystals with APDs
Carbon alveoles
Thermal shield
Support feet
Support beam
Drivers
FPGA:
• Online pulse data
processing
Assembly of Modules
• Rear view (off-beam)
including flat cables of
embedded PT100
sensors
• Front view (beam facing)
• Precise mounting of
APDs in glueing
gauges with defined
glueing force
• Assembled
detector wrapped
in reflective foil
and equipped with
termination
capsule
• APDs irradiated with 60Co
gammas and screened for
matching characteristics
Assembly of Supermodules
Assembly of first Barrel Slice
• A Supermodule consisting of .
. three Modules
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