Panels a–b: Temporal profiles of energies of six wave-field components (E_x, E_y, E_z, B_x, B_y, and ΔB_z) with n_e/n₀ = 5% and 50%. Panels c–b: Temporal energy profiles of the Z, X2, O1, and X3 modes. The energies are normalized to the respective initial kinetic energy of energetic electrons (E_ke0). The dark line refers to the relative decline in the kinetic energy of the electrons.