EM Calorimeter Shower (Heitler / Rossi)

Как это работает

**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.

Основные формулы