EM Calorimeter Shower (Heitler / Rossi)
This interactive simulator explores EM Calorimeter Shower (Heitler / Rossi) in Astronomy & The Sky. Toy electromagnetic cascade in a calorimeter: γ → e⁺e⁻, e⁻ → e⁻γ each X₀, with critical-energy cutoff E_c. Animate the branching tree, see N_max ≈ E₀/E_c, t_max ≈ log₂(E₀/E_c) live; presets for Pb, Cu, Si, air. Use the controls to change the scenario; watch the visualization and any graphs or readouts to connect the model with lectures, labs, and homework.
Who it's for: For learners comfortable with heavier math or second-level detail. Typical context: Astronomy & The Sky.
Key terms
- calorimeter
- shower
- heitler
- rossi
- em shower heitler
- astronomy
How it works
**Heitler–Rossi electromagnetic shower** — a toy model of how a high-energy γ or electron deposits energy in a calorimeter. Every radiation length **X₀**, an electron emits a bremsstrahlung **γ** and every γ pair-produces an **e⁺e⁻** with the energy split 50:50, until each daughter falls below the **critical energy E_c**, at which point ionisation losses dominate and the cascade dies. The number of particles roughly doubles each X₀, giving the classic **N_max ≈ E₀/E_c** at depth **t_max ≈ log₂(E₀/E_c)** — the basis of all sampling-calorimeter design (LHC, CMS ECAL, ATLAS LAr). Animate the cascade growing into a lead absorber.
Key equations
More from Astronomy & The Sky
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