Curves F(ρ_int/ρ_ext, L_||/ℓ_⊥0, δB/B₀, l_⊥0/Δr) = 0 are represented in the (ρ_int/ρ_ext, L_||/ℓ_⊥0)-plane, for δB/B₀ = 0.01 (purple line), δB/B₀ = 0.02 (green line), and δB/B₀ = 0.03 (orange line); each curve is calculated for ℓ_⊥0/Δr = 1. The portion of the plane below a given curve corresponds to the regime defined by condition (7) (phase mixing + nonlinear cascade regime), while the portion above the curve corresponds to the opposite condition (nonlinear cascade regime). The black dot indicates the configuration considered in Run 20.