Detailed calculation of inner-shell impact ionization to use in photon transport codes

► Some photons interactions produce also electrons as secondary particles. ► Inner-shell impact ionization (ISII) enhances XRF characteristic lines. ► PENELOPE is used to quantify the ISII in terms of angle, space and energy. ► A new photon kernel comprising the correction due to ISII is introduced. ► The impact of the ISII correction is discussed for the most intense K and L lines.