X-ray resonant Raman scattering on Ni employing polarized and unpolarized exciting radiation

The X-ray resonant Raman scattering effect on nickel was studied by means of monochromatic polarized and unpolarized exciting radiation, respectively. Experiments involving polarized exciting radiation were carried out at the four crystal monochromator beamline of the Physikalisch-Technische Bundesanstalt for synchrotron radiation from 4 to 10 keV at the electron storage ring BESSY II. Resonant Raman spectra of thin Ni foils were recorded at the Cu-Kα (8041 eV) exciting beam energy. In the Institute of Nuclear Physics of the N.C.S.R. Demokritos, the resonant Raman spectrum of a thick nickel target was also recorded for an unpolarized Cu-Kα (8041 eV) exciting beam produced after the ionization of a thick Cu target by 1.7 MeV protons in a triaxial, orthogonal geometry.In the present work, the individual spectral characteristics and the methodological approaches adopted for the extraction of the Ni-RRS cross sections, with respect to each mode of excitation, are presented, compared and discussed. An excellent agreement was found between the Ni KL-RRS cross sections determined for polarized and unpolarized exciting radiation confirming the theoretical predictions within the experimental uncertainties achieved.