Gauss broadening of X-ray laser lines by electric potential fluctuations inside atomic nuclei

Abstract
The broadening of X-ray laser lines by fluctuations of electric potential inside corresponding nuclei is studied. The fluctuations are produced by neutron-proton and proton-neutron transformations when localization of electric charge inside heavy nuclei changes. Atomic (and ionic) bound electrons "feel" such fluctuation as non-central Coulomb potential. It is shown that the potential fluctuations have the Gauss distribution while nuclei are considered as drops both of normal and Fermi-liquids. Finally, an electron level asquires the Gauss broadening. Estimations show that the linewidth can be of the same order as the Doppler width for highly-ionized plasmas ions.