This is a 2D cross-section of the same real ICF implosion, but instead of tweening a precomputed answer it time-steps the actual equations. During the laser pulse the shell mass gains kinetic energy from the ablation-driven rocket effect:
dKE/dt = η(t)·P_laser(t)
v(t) = √(2·KE(t) / m_shell) (integrated every substep)
a(t) = dv/dt
η is the laser→shell coupling efficiency; it degrades with drive asymmetry, and asymmetry seeds a real Rayleigh–Taylor instability on the ablation front. Growth is integrated alongside the drive with ablative stabilization (which smooths short-wavelength modes but barely touches the large-scale, low-order asymmetry a sparse beam pattern leaves behind):
γ_RT = max(0, √(k·a·Atwood) − k·V_abl)
Amp(t+dt) = Amp(t)·exp(γ_RT·dt)
When the shell stops accelerating it coasts inward and adiabatically compresses the DT fuel core — real PdV work — found by solving energy conservation for the compression ratio directly, rather than assuming it:
½ m v² = (3/2) N k T₀ [ (R₀/R_f)² − 1 ] (γ = 5/3 monatomic fuel)
T_core = T₀ (R₀/R_f)², n_core = N / ((4/3)π R_f³)
Ignition is judged by the real Lawson triple product — density × confinement time × temperature — rather than a proxy: the confinement time is the sound-crossing time of the compressed core (τ = R_f / 4c_s, Atzeni & Meyer-ter-Vehn's inertial-confinement form), and ignition requires n·τ·T to clear the DT threshold. If the Rayleigh–Taylor amplitude at the fuel–pusher interface still exceeds ~35% of the core radius at stagnation, the shell has broken up and mixed cold pusher material into the hot spot — a real, documented ICF failure mode that quenches ignition even when the triple product alone would have been enough.