General picture of the numerical setup for AW collision. Top: physical setup; early phase. The green rectangle denotes the numerical box with equilibrium plasma, the red and blue areas represent velocity perturbations (positive and negative) of the z⁻ wave (far boundary) and z⁺ wave (near boundary). Polarization planes and nonuniformity directions are annotated. Bottom: longitudinal sketches; late phase after AW collision. Main setups with one period in z⁻ and three periods in the z⁺ wave (left), and complimentary setups with one period in each wave (right). The gray areas denote cross-sections taken for further analysis.