Evolution of magnetic field model II using ζ = 10⁻⁴. We used a grid of N_r = 60 radial steps and N_θ = 91 polar steps inside the core, N_Exp = 40 external multipoles, u = 2/3, and the HHJ EoS. From left to right: Configuration of the magnetic field, where lines represent the poloidal magnetic field (labeled by the magnitude of α) and colors the poloidal potential α; χ_n and χ_c, both in units of χ₀ = B₀²/4πn₀μ₀; neutron velocity, v_n, and ambipolar diffusion velocity, v_ad, where arrows represent the direction and colors the magnitude normalized to R/t₀. Rows correspond to different times: t = 0, t = t_ζB = 10⁻⁴ t_ad, and t = 0.1 t_ad.