Time-resolved IR spectra from electron irradiation of CaCO₃ at 50, 100, and 120 K under two electron fluxes, normalized to the preirradiation CaCO₃ baseline and truncated to the 4.2–4.3 μm region to highlight the CO₂ ν₃ band. Vertical dashed lines mark the central wavelengths of the CO₂ doublet, determined from double Gaussian fits to the continuum-removed spectra (gray). CO₂ absorptions appear upon irradiation and gradually saturate. The strongest absorptions occur at 50 K under high flux. At higher temperatures, the absorptions are weaker, but radiolytic CO₂ production is still apparent.