Atomic form factors and photoelectric absorption cross-sections near absorption edges in the soft X-ray region

2003 ◽  
Author(s):  
C. T. Chantler
Keyword(s):  
Cross Sections ◽  
Form Factors ◽  
Absorption Cross ◽  
Photoelectric Absorption ◽  
X Ray ◽  
Absorption Edges

A Determination of Screening Constants for Incomplete Atomic Shells of Elements Z = 2 to 23 from Experimental Ionization Potentials — X-ray Photoelectric Mass Absorption Coefficients for Elements Z = 6 to 15 for 33 Characteristic Energies between 1 and 25 keV

1976 ◽  
Vol 31 (8) ◽  
pp. 887-897 ◽  
Author(s):  
J. D. Stephenson
Keyword(s):  
Cross Sections ◽  
Ionization Potentials ◽  
Absorption Cross ◽  
Photoelectric Absorption ◽  
Absorption Coefficients ◽  
Spin Doublet ◽  
X Ray ◽  
Mass Absorption ◽  
Comparison With Experiment

AbstractA method is proposed, which primarily determines screening constants for incomplete atomic shells from the experimental ionization potentials of spin-paired Pauli-type orbitals. The method is complimentary and in addition to the standard Sommerfeld approach, which derives screening constants from X-ray spin doublet term differences. Atomic photoelectric absorption cross sections are computed from screened hydrogen-like eigenfunctions for low atomic number elements Z = 6 to 15, using a range of incident photon energies between 1 and 30 keV. Comparison with experiment and alternate more exact theories shows, that improved cross sections are obtained for the more important incomplete L-shell contributions. X-ray photoelectric mass absorption coefficients for low Z elements (Z= 6 to 15), employing 33 characteristic X-ray energies {NiKα (0.852 keV) to AgKβ (24.942 keV)}, are given.

scholarly journals Anisotropy of X-ray Absorption Cross Section in CeCoGe3 Single Crystal

Crystals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 544
Author(s):  
Andrei Rogalev ◽  
Fabrice Wilhelm ◽  
Elena Ovchinnikova ◽  
Aydar Enikeev ◽  
Roman Bakonin ◽  
...  
Keyword(s):  
Cross Section ◽  
Absorption Cross Section ◽  
Linear Dichroism ◽  
X Rays ◽  
Absorption Cross ◽  
X Ray ◽  
Measured Absorption ◽  
Linearly Polarized ◽  
X Ray Absorption ◽  
Absorption Edges

Absorption spectra of two orthogonal linearly polarized x-rays in a single CeCoGe3 crystal were measured at the ID12 beamline of the ESRF for the energies near the K-edges of Ge, Co and near the L23 edges of Ce. The X-ray natural linear dichroism (XNLD) was revealed in the vicinity of all the absorption edges, which indicates a splitting of electronic states in a crystalline field. Mathematical modelling in comparison with experimental data allowed the isotropic and anisotropic parts of atomic absorption cross section in CeCoGe3 to be determined near all measured absorption edges. The calculations also show that the “average” anisotropy of the cross section close to the Ge K-edge revealed in the experiment is less than the partial anisotropic contributions corresponding to Ge atoms in two different Wyckoff positions.

scholarly journals Fullerite C60 optical constants in the C 1s NEXAFS region

2021 ◽  
Vol 2103 (1) ◽  
pp. 012168
Author(s):  
D V Sivkov ◽  
S V Nekipelov ◽  
O V Petrova ◽  
D V Bogachuk ◽  
R N Skandakov ◽  
...  
Keyword(s):  
Cross Sections ◽  
Optical Constants ◽  
Absorption Cross ◽  
X Ray ◽  
Carbon Absorption ◽  
Cross Section Spectrum ◽  
Integral Relations ◽  
Atomic Form Factor ◽  
Using Data ◽  
X Ray Absorption

Abstract Using data on the absorption cross sections the refraction coefficient spectral dependence n(E) and the spectra of the remaining optical coefficients (reflection coefficient, phase shift, and atomic form factor) in the fullerite C60 C 1s near edge X-ray absorption fine structure (NEXAFS) region (280–350 eV) were determined. For the n(E) calculations the Kramers-Kronig integral relations (KKRs) were used. The KKR computations were performed using data on atomic carbon absorption cross sections in the 10–30000 eV range and on solid and gaseous C60 – in the 0–120 eV. Absorption cross section spectrum in the fullerite C60 C 1s NEXAFS region were measured.

Approximation of photoelectric absorption cross sections

1971 ◽  
Vol 30 (4) ◽  
pp. 469-470
Author(s):  
L. V. Popova ◽  
L. A. Sholokhova
Keyword(s):  
Cross Sections ◽  
Absorption Cross ◽  
Photoelectric Absorption
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