Resonant Raman Scattering of synchrotron X-rays by neodymium: Observation of fine structure in K-L-RRS and of K-N-RRS

Abstract

Using monochromatized synchrotron radiation with variable photon energy E i --43.01 ... 43.35 keV, Resonant Raman Scattering (RRS) by Neodymium atoms (K-shell binding energy Bls=43.57keV) was investigated. For the first time the fine structure splitting in a K-L-RRS spectrum due to the energy difference of the L 2 and L 3 subshells was observed. In addition, the first observation of K-N-RRS in the spectrum of scattered photons is reported. The measured double-differential RRS cross sections are, on an absolute scale, in very good agreement with those calculated in the nonrelativistic dipole approximation, modified by relativistic corrections.

Measurement of KL and LM resonant Raman scattering cross sections with a proton-induced x-ray beam

“…The starting point for theoretical calculation of the RRS cross section according the non-relativistic dipolar approximation, is the so-called modified Kramers-Heisenberg-Waller (KHW) formula [19]. Calculations have been done mainly for the KL-RRS [7,13,14,[20][21][22], although recently LM-RRS was described in the vicinity of the L III absorption edge [23]. The KHW formula includes a resonant term with a summation over all the intermediate states involved a K-shell hole with a finite lifetime and an electron in the continuum.…”

“…Total KL-RRS cross sections have been measured for various elements (Cr, Mn, Fe, Ni, Cu, Zn) using conventional x-ray tubes with a monochromator [5,10] and tunable synchrotron radiation [9,13]. Observation of the fine structure in KL-RRS and KN-RRS was reported by Shaupp et al [14] for Nd, while the cross section for the KM contribution to the RRS for Mo was measured by Kodre and Shafroth [15]. The study of LM-RRS in literature is scarce and it has been done in only two cases.…”

Rayleigh, Compton and K-shell radiative resonant Raman scattering in 83Bi for 88.034keV γ-rays

“…The variation of X-ray spectral energies, line shapes and a resonant increase in intensity of the scattered photons near the absorption edge observed in the experiments are explained by theoretical treatments based on the resonant term of the Kramers-Heisenberg formulation of photon-scattering processes [5][6][7][8]. Most of the resonant Raman scattering (RRS) cross-sections measurements have been performed using the tuneable synchrotron radiation sources (SRS) with various monochromatising techniques [3,[9][10][11][12]. Karydas and Paradellis [13] have used modest resolution of a solid-state detector to measure the KL RRS in 23 V and 24 Cr, and the LM RRS in 57 La and 58 Ce using Cr Ka X-rays from a proton-induced source and a monochromator.…”