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0.7 cm (1.2 cm). 0.3 cm. 3/31/2008 M. Konno. HCal Simulation with Geant4. 1. Setup. Particle: + (E in = 0.5-100 GeV) Processes: - Decays - EM interaction - Hadronic interaction (Model: LHEP_BERT) Items: - Efficiency - Energy loss (<E>, resolution)
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0.7 cm (1.2 cm) 0.3 cm 3/31/2008 M. Konno HCal Simulation with Geant4 1. Setup Particle: +(Ein = 0.5-100 GeV) Processes: - Decays - EM interaction - Hadronic interaction (Model: LHEP_BERT) Items: - Efficiency - Energy loss (<E>, resolution) - Shower profile (transverse) 200 cm (Z) 200 cm (Y) 50 cm (X) (75 cm) Absorber: (Pb or Fe) • - 50 layers • 1 layer = 1.0 cm • (1.5 cm) Scintillator
2. Particle Shot Single particle (+, Ein = 10 GeV) (Absorber: Fe, 12 mm)
3. Energy loss in calorimeter (Absorber: Fe, 12 mm) (same data in log scale) Lower tail seen
4. Efficiency (for shower) ~95 % for 12 mm ~85 % for 7 mm
5. Energy loss (Eloss>50MeV) * Secondary particles flow out?
6. Energy resolution (RMS/Mean, Eloss>50MeV) * Only small fraction of particle energy measured. It’s not the total energy.
7-1. Shower profile - dE/dx vs. x (beam direction: x) (Absorber: Pb, 7mm) (Absorber: Fe, 7 mm) * The dE/dx distributions are different between Pb and Fe.
7-2. Shower profile - dE/dx vs. x (beam direction: x) (Absorber: Pb, 12 mm) (Absorber: Fe, 12 mm) * The dE/dx distributions are different between Pb and Fe.
8-1. Shower profile - dE/dr vs. r (Absorber: Pb, 7mm) (Absorber: Fe, 7 mm)
8-2. Shower profile - dE/dr vs. r (Absorber: Pb, 12 mm) (Absorber: Fe, 12 mm)
9-1. Shower profile – R vs. Ein • The radius not changing much with Ein • The energy loss is centered • (In other words, a long tail seen around the center) • R(Fe) < R(Pb)
9-2. Shower profile – R vs. Ein • The radius not changing much with Ein • The energy loss is centered • (In other words, a long tail seen around the center) • R(Fe) < R(Pb)
10. Summary • The energy loss (<E>, E) and efficiency are • not so different between two absorbers Pb and Fe. • Efficiency: ~85% for absorber length = 35 cm (0.7 cm x 50 layers) • Efficiency: ~95% for absorber length = 60 cm (1.2 cm x 50 layers) • R80(Fe, 12mm): ~12 cm, R80(Pb, 12mm): ~21 cm • R(Fe) < R(Pb) Next to do • - Put EMCal in front of HCal • - Introduce the photon detection efficiency • Study the segmentation in YZ plane • with PYTHIA jet information as Pb+Pb collisions • Optimize the materials and geometry parameters • to fit in ALICE detector • Try to use other hadronic models