Evaluation of the error and applicability of various screening lengths for a 70 M_⊙ He core progenitor. Each point in the figures corresponds to an individual mass-time coordinate in the overall evolution of this model from the start of the simulation to the final collapse. Top left: calculated screening length for the entire evolution of the star. The transition from relativistic screening to classical screening occurs at a temperature of 150 keV. The points mesh seamlessly here. Top right: the relative uncertainty between the approximation of Eq. (8) and the exact numerically calculated screening length. Bottom left: the screening length computed using the approximation of Eq. (8) for kT > 150 keV. Bottom right: the exact numerically calculated screening length for kT > 150 keV.