Deconvolution of atomic photoabsorption spectra: A match between theory and experiment

We present in this paper an extension of a recently proposed deconvolution procedure to compare directly the theoretical and experimental spectrum of a doubly excited ultra-narrow and nearly symmetric resonance in atomic phot oabsorption. Our discussion is based on a set of analytical relations in te rms of the variations of i) the ratio between the resonance width Gamma and the experimental energy resolution Omega in the limit when Gamma/Omega muc h less than 1 and ii) the column density nl of the media in a photoabsorpti on experiment.