The Barrel Electromagnetic Calorimeter

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The Barrel Electromagnetic Calorimeter

• Layout
• Current Status
• - Hardware installation
• - Calibration
• - Analysis
• Capabilities
• Possible tasks and our contributions

André Mischke EMC Sub-Group Meeting June 24,
2003
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The STAR Detector _at_ RHIC
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The STAR BEMC

• 60 modules in azimuthal and 2 in h
• each module consists out of 40 towers (2 in f
  and 20 h)
• ? 4800 Towers

Side view
End view
-1 lt h lt 1 and Dh 0.05
0 lt f lt 2p and Df 0.05 (3o)
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BEMC Module
Production
30.1cm
293cm
26cm
Installation
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BEMC Module (contd)

• Lead-scintillator sampling
• (each 5mm thick)
• 20 radiation length X0
• dE/E 14/vE

Lead
Scintillator
EMC Module
EMC Tower
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BEMC modules near mid-rapidity
SMD Shower Maximum Detector PSD Preshower
Detector
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Shower Maximum Detector
for two-dimensional spatial resolution

• Located after 5 X0
• wire proportional counter with strip read-out
• two independent layers
• (perpendicular orientated)
• 300 strips per module
• using gas amplification
• (??, ??) (0.007, 0.007)

Tower SMD PSD 45.600 channels
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What is installed up to now

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Status after dAu Run (A. Suaide)

• Towers
• About 100(68)/2400 dead or noisy
• 1 bad digitizer board (32) channels (replaced)
• 68 noisy/dead channels
• HV is set to zero for all of them
• 3 dead crates (power supply failures)
• Replaced during accesses
• SMD
• 3/60 modules not working
• 1/3 bad FEE
• 2/3 need access inside the detector to diagnose
• Some individual channels
• Some we know are dead
• Zero pedestal and no readout
• Some are noisy

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Status Calibration

• Absolute calibration
• Beam-Test in 98 (?- with 0.3-8 GeV/c)
• ? average tower gain 7.5 MeV/ADC counts
• Pedestal correction
• Relative calibration
• Equalization of all towers in the same
• ? bin
• MIP calibration

Equalized ? bin spectra (Dh 0.1) after 850
minibias events
Minimum ionizing particles (charged hadrons)
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Status Analysis

• Au-Au run (2000)
• Transverse energy measurement
• (paper ready for publication)
• Electron identification
• p-p run (2002)
• p0 spectrum
• Electron identification with SMD
• d-Au run (2003)
• p0 spectrum

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Capabilities of the BEMC

• Inclusive ?0 and ? spectra (high-pT)
• ?0 -charged track correlations at high-pT
• Direct photons
• Jet-? events
• Electron high-pT spectra
• J/? (ee- channel) T.Ullrich
• Y (ee- channel) T.Kollegger
• Data available p-p, d-Au and upcoming Au-Au

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BEMC group

• University of São Paulo A. Suaide (calibration,
  e- ID.)
• M. de Moura (calibration, ET)
• UCLA S. Trentalange (Trigger)
• D. Thein
• O. Tsai
• Wayne State University T. Cormier
• A. Pavlinov
• 
  A. Stolpovsky (?0 in dAu)
• NIKHEF/Utrecht Thomas, Michiel, Oleksandr,
  André,

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Possible tasks and our contribution (?)

• Corruption in the trigger data
• Gain variation with time
• Calibration e.g. channel instabilities
  (necessary for the Simulations)
• Matching tower ? SMD

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Add. slides
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d-Au Data