Measurement of L X-ray fluorescence cross-sections for 74 W at excitation energies 12, 14, 15 and 16.5 keV with synchrotron radiation

2017 ◽  
Vol 131 ◽  
pp. 79-85 ◽  
Author(s):  
R. Kumar ◽  
A. Rani ◽  
R.M. Singh ◽  
M.K. Tiwari ◽  
A.K. Singh
Keyword(s):  
Synchrotron Radiation ◽  
Cross Sections ◽  
Excitation Energies ◽  
X Ray

X-Ray Fluorescence Cross-Section Measurements in the Energy Range 4-18 keV

1995 ◽  
Vol 39 ◽  
pp. 845-855
Author(s):  
Krassimir N. Stoev ◽  
Joseph F. Dlouhy
Keyword(s):  
Cross Sections ◽  
Transition Probabilities ◽  
Weighted Average ◽  
Physical Parameters ◽  
Emission Rates ◽  
Excitation Energies ◽  
X Ray ◽  
Fluorescence Cross Section ◽  
Theoretical Results

K, L and M shell x-ray fluorescence cross sections have been measured for elements 11 ≤, Z ≤, 92 at excitation energies corresponding to weighted average energies of K-lines of Ti-K (4.558 keV), Fe-K (6,480 keV), Ge-K (10.024 keV), Se-K (11.391 keV) and Mo-K (17.805 keV) . The measurements were performed with an energy-dispersive x-ray spectrometer in a vacuum chamber using thin ultra-pure targets. Rh x-ray tube and secondary targets were used for excitation of x-ray radiation. The measured x-ray fluorescence cross-sections have been compared to previously published experimental and theoretical results. Presented data can be used for determination of physical parameters such as photoionization cross-sections, fluorescence yields, x-ray emission rates, Coster-Kronig transition probabilities and jump ratios.

Measurement of L X-ray fluorescence cross-sections for elements with 45 ⩽Z⩽50 using synchrotron radiation at 8keV

2011 ◽  
Vol 269 (19) ◽  
pp. 2084-2089 ◽  
Author(s):  
Edgardo V. Bonzi ◽  
Nagappa M. Badiger ◽  
Gabriela B. Grad ◽  
Raúl A. Barrea ◽  
Rodolfo G. Figueroa
Keyword(s):  
Synchrotron Radiation ◽  
Cross Sections ◽  
X Ray

scholarly journals Ultra-stable sub-meV monochromator for hard X-rays

2015 ◽  
Vol 22 (5) ◽  
pp. 1155-1162 ◽  
Author(s):  
T. S. Toellner ◽  
J. Collins ◽  
K. Goetze ◽  
M. Y. Hu ◽  
C. Preissner ◽  
...  
Keyword(s):  
High Resolution ◽  
Synchrotron Radiation ◽  
High Speed ◽  
Room Temperature ◽  
Energy Calibration ◽  
Nuclear Transition ◽  
X Rays ◽  
Excitation Energies ◽  
Transmitted Beam ◽  
X Ray

A high-resolution silicon monochromator suitable for 21.541 keV synchrotron radiation is presented that produces a bandwidth of 0.27 meV. The operating energy corresponds to a nuclear transition in151Eu. The first-of-its-kind, fully cryogenic design achieves an energy-alignment stability of 0.017 meV r.m.s. per day, or a 100-fold improvement over other meV-monochromators, and can tolerate higher X-ray power loads than room-temperature designs of comparable resolution. This offers the potential for significantly more accurate measurements of lattice excitation energies using nuclear resonant vibrational spectroscopy if combined with accurate energy calibration using, for example, high-speed Doppler shifting. The design of the monochromator along with its performance and impact on transmitted beam properties are presented.

Narrow-Band Synchrotron Radiation Excitation of Soft X-Ray Emission Spectra

1993 ◽  
Vol 307 ◽  
Author(s):  
K. E. Miyano ◽  
W. L. O'Brien ◽  
D. L. Ederer ◽  
T. A. Callcott ◽  
J. J. Jia ◽  
...  
Keyword(s):  
Synchrotron Radiation ◽  
Excitation Energy ◽  
Crystalline Silicon ◽  
Narrow Band ◽  
Emission Spectra ◽  
Phonon Coupling ◽  
Excitation Energies ◽  
Final State ◽  
X Ray ◽  
The Core

ABSTRACTMonochromatized synchrotron radiation has been employed as the excitation source for soft x-ray emission spectroscopy. In the present paper changes in the emission spectra that occur as the excitation energy is varied near the core-absorption threshold are discussed. In the case of crystalline silicon, strong variations are seen in the L2,3 emission for excitation energies up to 30 eV above threshold. These variations are shown to be dependent on the crystalline order of the material and can be interpreted in terms of restrictions on the crystal momentum that arise in an inelastic scattering description of the combined absorption and emission. On the other hand this description is less relevant to the excitation-energy dependence of ionic insulators, in which strong phonon coupling removes these restrictions on crystal momentum. In the insulators B2O3 and BN strong variations in the emission are observed at threshold, upon creation of a core exciton: the exciton affects the emission through its influence on the phonon coupling as well as on the initial and final-state screening.

scholarly journals How to Stay out of Trouble in RIXS Calculations Within Equation-of-Motion Coupled-Cluster Damped Response Theory? Safe Hitchhiking in the Excitation Manifold by Means of Core-Valence Separation

2019 ◽  
Author(s):  
Kaushik Nanda ◽  
Marta L. Vidal ◽  
Rasmus Faber ◽  
Sonia Coriani ◽  
Anna Krylov
Keyword(s):  
Cross Sections ◽  
Equation Of Motion ◽  
Coupled Cluster ◽  
Response Theory ◽  
Excitation Energies ◽  
X Ray ◽  
X Ray Scattering ◽  
Novel Approach ◽  
Response Equation ◽  
Divergent Behavior

<div>We present a novel approach for computing resonant inelastic X-ray scattering (RIXS) cross sections within the equation-of-motion coupled-cluster (EOM-CC) framework. The approach is based on recasting the sum-over-state expressions for RIXS moments into a compact form by using damped response theory. Damped response formalism allows one to circumvent problems of divergent behavior of the response equation in the resonant regime. However, the convergence of response equations in the X-ray frequency range is often erratic due to the resonant nature of the virtual core-excited states embedded in the valence ionization continuum. We demonstrate that this problematic behavior can be avoided by extending the core-valence separation (CVS) scheme, which decouples the valence-occupied and core-occupied excitation manifolds, into the response domain. The accuracy of the CVS-enabled damped response theory, implemented within the EOM-EE-CCSD (EOM-CC for excitation energies with single and double excitations) framework, is assessed by comparison against damped EOM-EE-CCSD response calculations. The capabilities of the new approach are illustrated by calculations of RIXS cross sections for benzene and benzene radical cation.</div>

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