Proposal for IHEP participation in CBM ECAL

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Proposal for IHEP participation in CBM ECAL

• Yuri Kharlov
• Institute for High Energy Physics
• Protvino

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Outline

• Scintillator sampling calorimeters manufactured
  in IHEP
• IHEP plastic scintillator facility
• Simulations and data analysis

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Scintillator calorimeters

• IHEP has a long history of electromagnetic and
  hadron calorimetry contributed to many of
  HEP-experiments.
• Different types of e.m. calorimeters were
  manufactured in IHEP
• Cherenkov calorimeters (lead glass)
• Scintillator sampling calorimeters
• Scintillating crystal calorimeters (PbWO4)
• Scintillator sampling calorimeters
• 1985 invention of the molding technology
• 1988 first shashlyk RD with INR
• 1992 PHENIX ECAL (BNL, RHIC)
• 1993-1995 HERA-B ECAL (DESY, with ITEP)
• 1994 DELPHI STIC (CERN, LEP)
• 2000 COMPAS HCAL (CERN, SpS)
• 2001 ATLAS HCAL (CERN, LHC)
• 2004 LHCb HCAL (CERN, LHC)
• 2000-200? KOPIO (BNL, AGS)

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E.M. calorimeter in PHENIX
PHENIX Tech. Note 236, 06/96
RD 1994 Typical sampling lead-scintillator
calorimeter of 15,552 channels 66 sampling
layers DE/?E8 at 1 GeV Time resolution 100
ps 36 fibers of WLS-doped polysterene penetrate
the modules Modules are assembled into 6x6-array
supermodules
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E.M. calorimeter STIC in DEPLHI
NIM A 425 (1999) 106 Small angle Tile Calorimeter
for luminosity monitoring 47 Pb(3mm)-Sci(3mm)
layers 2 Si strip detectors inserted after 7 and
13 sampling layers to measure shower
development 1600 WLS fibers (0.79
fiber/cm2) DE/?E3 at 45 GeV Df1.5? Dr0.3-1 mm
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E.M. calorimeter in KOPIO
First prototype for KOPIO (INR, Troitsk) 240 ?
(0.35 mm lead 1.5 mm scint.) Energy resolution
?4??E(GeV). (for 1 GeV/c positron)

Contributions to the energy resolution
E865
E923
KOPIO prototype
To achieve the energy resolution of 3??E(GeV)
the sampling, photo-statistics and light
collection uniformity have to be improved
Test beam results and the simulation model is
described in NIM A 531 (2004) 476
Economy adequate performance for 1/10 cost of
crystals
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KOPIO 3/?E
CALOR 2004, Perugia, Italy, March 29-April 2, 2004
Lateral segmentation 110?110 mm2
Scintillator thickness 1.5 mm
Gap between scintillator tiles 0.300 mm
Lead absorber thickness 0.275 mm
Number of the absorber layers (Lead / Scint) 300
WLS fibers per module 72 ? 1.6 m 115 m
Fiber spacing 9.3 mm
Holes diameter in Scintillator / Lead 1.3 mm / 1.4 mm
Diameter of WLS fiber (Y11-200MS) 1.0 mm
Fiber bundle diameter 14.0 mm
External wrapping (TYVEK paper) 150 ?
Effective Xo 34.0 mm
Effective RM 59.8 mm
Effective density 2.75 g/cm3
Active depth 540 mm (15.9 Xo)
Total depth (without Photodetector) 650 mm
Total weight 18.0 kG
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KOPIO Calorimeter module

• The design innovations
• New scintillator tile (BASF143E 1.8pTP
  0.04POPOP produced by IHEP) with improved
  optical transparency and improved surface
  quality. The light yield is now 60 photons per
  1 MeV of incident photon energy. Nonuniformity
  of light response across the module is lt2.3 for
  a point-like light source, and lt 0.5 if
  averaged over the photon shower..
• New mechanical design of a module has four
  special "LEGO type" locks for scintillators
  tiles. These locks fix the position of the
  scintillator tiles with the 300-?m gaps,
  providing a sufficient room for the 275 ?m lead
  tiles without optical contact between lead and
  scintillator. The new mechanical structure
  permits removing of 600 paper tiles between
  scintillator and lead, reduces the diameter of
  fibers hole to 1.3 mm, and removes the
  compressing steel tape. The effective radiation
  length X0 was decreased from 3.9 cm to 3.4 cm.
  The hole/crack and other insensitive areas were
  reduced from 2.5 up to 1.6 . The modules
  mechanical properties such as dimensional
  tolerances and constructive stiffness were
  significantly improved.
• New photodetector Avalanche Photo Diode
  (630-70-74-510 produced by Advanced Photonix
  Inc.) with high quantum efficiency (93), good
  photo cathode uniformity (nonuniformity ? 3) and
  good short- and long-term stability. A typical
  APD gain is 200, an excess noise factor is 2.4.
  The effective light yield of a module became 24
  photoelectrons per 1 MeV of the incident photon
  energy resulting in negligible photo statistic
  contribution to the energy resolution of the
  calorimeter.

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KOPIO light yield in scintillator
Scintillator PSFluor1Fluor2, Manufacturer Light yield ( of Anthracene) Attenuation Length (cm) Light yield of MIP, p.e. per tile Simulated light collection efficiency
PSM1151.5pTP0.04POPOP, TECHNOPLAST, 1998 53 ? 6 4.0 ? 0.3 4.4 ? 0.3, 100 0.134 ? 0.013, 100
BASF158K1.5pTP0.04POPOP, IHEP, 2001 56 ? 6 4.9 ? 0.4 5.6 ? 0.3, (127 ? 10) 0.170 ? 0.017, (127 ? 13)
BASF165H1.5pTP0.04POPOP, IHEP, 2001 56 ? 6 6.1 ? 0.5 6.4 ? 0.3 (145 ? 10) 0.191 ? 0.019, (143 ? 14)
BASF143E1.5pTP0.04POPOP, IHEP, 2002 54 ? 6 6.8 ? 0.5 7.1 ? 0.3, (161 ? 10) 0.215 ? 0.021, (160 ? 16)
Light yield variation over tiles samples
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KOPIO light collection in the tile
Tile (face view)
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KOPIO energy resolution
Energy resolution for 220-370 MeV photons
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KOPIO time resolution
Time difference in two modules was measured
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KOPIO photon detection inefficiency
Simple estimate of Inefficiency (due to holes)
Effect of holes is negligible if incident angle gt
5 mrad
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Calorimeter readout

• Readout systems (photo-multipliers and
  high-voltage system) were provided by IHEP for
  PHENIX (16 000 channels), HERA-B (6000 channels)
  LHCb (6500 ECAL1800 HCAL channels)
• IHEP together with MELZ is working on
  modernization of the photo-multipliers PMT115M
  with low rate effect. First prototypes with
  stability 1 at I20mA were produced.

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Plastic scintillator facility in
IHEPhttp//www1.ihep.su/ihep/ihepsc/index.html

• The research and development program of plastic 
  scintillators started in IHEP morethan 20 years
  ago. The works were concentreted in the following
  directions
• the production of polysterene scintillators using
  the process of styrene polymerization in blocks
• the extrusion of bulk-polymerized scintillators
  from blocks
• the production of molded scintillators by the
  injection molded technique.
• Scintillators manufactured be methods 1 and 2
  were tested and used in domestic experiments at
  IHEP as well as some experiments abroad
• With the help of method 3, large volumes of
  scintillators for several experiments in IHEP (3
  tons) and for hadron calorimeters Hcal1 and Hcal2
  of experiment in COMPASS (2 tons) were
  manufactured.
• During the last decade the demand on molded
  scintillators for various projects (PHENIX,
  HERA-B, ATLAS, LHC-b) have inceased up to several
  tens of tons per year.
• Production time scale 15 tons of scintillators
  (gt750,000 plates) for KOPIO could be manufactures
  in 1.5 years.

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Plastic scintillator facility in IHEP
Injected mold machime in automatic processing of
the tiles.
Injected mold scintillator production facility
3x3 module for KOPIO
Plates for KOPIO
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ECAL simulations and data analysis

• IHEP group has experience in e.m. calorimeters
  simulations and data analysis, particularly in
  heavy-ion experiments (PHENIX, STAR, ALICE) which
  should be similar to CBM in complexity.
• Calibration
• Shower shape measurements
• Shower reconstruction
• Particle identification (photons, electrons,
  hadrons)
• Physics analysis

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ECAL calibration
Calibration by wide electron beam with
minimization of the mean quadratic deviation
Before calibration
After calibration
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Shower shape measurement(PbWO4 calorimeter)
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Particle identification

• PID in ECAL based on
• Shower shape
• TOF
• Charge track matching
• Good identification of photons, electrons,
  charged and neutral hadrons, (anti)nucleons.
• GEANT3 simulation for PHOS, ALICE

?
e-
anti-n
p-
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p0 spectrum and background subtraction (Pb-Pb at
5.5 ATeV)
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IHEP contribution to CBM ECAL

• Participating together with other member
  institutes in
• Defining physics motivation for ECAL in CBM
• Conceptual desing of ECAL
• RD
• Detailed simulation to optimize ECAL parameters
• Beam-tests of the prototypes in IHEP and GSI
• ECAL readout (PMTHV system)
• Monitoring system
• Data analysis
• Full responsibility for manufacturing of the ECAL
  modules (Pb-Sci sampling).