Photoabsorption cross sections: Effect of 'radiation hardening'

Our knowledge on the effective photoabsorption cross sections of the solar Extreme Ultraviolet/Ultraviolet (EUV/UV) emissions should be improved to increase the accuracy of the first principle thermospheric/ionospheric models. In this context the effect of 'radiation hardening' and possible implications are discussed. An experiment is proposed to derive a complete set of photoabsorption cross sections for the relevant EUV/UV spectral region.