Simulated spectrum and PD in the high-ionization regime under PIE (solid lines), viewed at an inclination angle of 75° relative to the slab normal. Results are shown for different temperatures of the blackbody radiation, T_BB = 0.32 (cyan), 0.56 (orange), 1.0 (green), and 1.78 keV (red), with the slab density adjusted to maintain a constant ionization parameter of log ξ ∼ 6 (see equation 2). Dotted lines represent simulations for the same values of the parameters but with all interactions except scattering processes artificially turned off in STOKES.