EM Calorimetry

• Electron Endcap: −4 < η < −1.7
  • PbWO4 crystals: 2cm x 2cm x 20 cm (> 20 X0)
  • Energy resolution 2%/(√ E) ⊕ 1% ⊕ 1%/E
  • Spatial resolution (isolated shower) 3mm / (√ E)
  • Readout: Si-PMT, with MCP-PMT at small radius (high neutron fluence)
    • Fill factor > 50%
  • Electonics: in situ ≥ 250 MHz Digitization (≥ 12 bits)
• Barrel: −1.7 < η < 0
  • PbWO4 crystals, 2D projective. Inner faces &approx; 2cm x 2cm. Projective depth 20 cm
  • Energy resolution 2%/(√ E) ⊕ 1% ⊕ 1%/E
  • Spatial resolution (isolated shower) 3mm / (√ E)
• Barrel, 0 < η < 1.4
  • W-Shashlik. 2D projective. Fiber spacing < 1cm. Projective depth 25 cm ( > 25 X0)
  • Energy resolution 6.3%/(√ E) ⊕ 2% ⊕ 2%/E
  • Two-cluster spatial separation: ≤ 1 cm
  • Readout: Si-PMT, each fiber diffused to unique pixel
  • Electonics: in situ ≥ 250 MHz Digitization (≥ 12 bits)
• Ion Endcap 1.4 < η < 4
  • W-Shashlik. 2D projective.