Angular variations of K and L X-ray fluorescence cross sections for some lanthanides

2008 ◽  
Vol 86 (2) ◽  
pp. 361-367 ◽  
Author(s):  
I Han ◽  
M Şahin ◽  
L Demir
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Emission Angle ◽  
X Rays ◽  
X Ray ◽  
Isotropic Distribution ◽  
Fluorescence Cross Section ◽  
Intensity Ratios ◽  
Experimental Values ◽  
Photon Source

Kα, Kβ, Lα, and Lβ X-ray fluorescence cross sections for lanthanides in the atomic range 62 ≤ Z ≤ 68 (Sm, Eu, Gd Tb, Dy, Ho, and Er) were simultaneously measured by 59.54 keV incident photon energy at five angles ranging from 120° to 160°. The measurements were performed using an Am-241 radioisotope as the photon source and a Si(Li) detector. The Lα X-ray fluorescence cross section (σLα) was found to decrease with increasing emission angle and showed an anisotropic distribution of Lα X-rays. Kα, Kβ, and Lβ X-ray fluorescence cross sections (σKα, σKβ, and σLβ) were observed to be angle-independent and showed an isotropic distribution of Kα, Kβ, and Lβ X-rays. The Kα and Kβ X-rays originate from filling of the K shell (J = 1/2) vacancies, Lβ X-rays from filling of the L1 and L2 (J = 1/2) subshell vacancies, and Lα X-rays from filling of the L3 subshell (J = 3/2) vacancy. The fluorescent X-rays originating from the vacancy states with J = 1/2 are isotropic and unpolarized, but fluorescent X-rays originating from the vacancy states with J > 1/2 are anisotropic and polarized. Thus, the atomic inner shells vacancy states with J > 1/2 are aligned whereas vacancy states with J = 1/2 are not aligned. Lα fluorescence X-rays have an anisotropic distribution, while Kα, Kβ, and Lβ fluorescence X-rays have isotropic distribution. Furthermore, the IKβ/IKα, ILα/IKα}, ILβ/IKα, and ILβ/ILα intensity ratios for the elements under investigation were determined. The experimental cross sections and intensity ratios for Kα, Kβ, Lα, and Lβ fluorescence X-rays were also determined, and these experimental values were compared with our calculated theoretical values.PACS Nos.: 32.30.Rj, 32.80.Cy

Measurement of L X-ray production cross sections and relative intensities of some lanthanide compounds depending on the temperature

2020 ◽  
Vol 108 (5) ◽  
pp. 415-423
Author(s):  
Esra Cinan ◽  
Bünyamin Aygün ◽  
M. I. Sayyed ◽  
Yüksel Özdemir
Keyword(s):  
Cross Sections ◽  
Full Width Half Maximum ◽  
Production Cross ◽  
Emission Spectra ◽  
X Rays ◽  
X Ray ◽  
Different Temperatures ◽  
Intensity Ratios ◽  
Annular Source

AbstractL X-ray intensity ratios for CeO2, Sm2(SO4)3, Ho2O3, and Yb2O3 compounds were experimentally investigated. The measurements were gauged following excitation by 59.54 keV γ-rays from a 100 mCi 241Am radioactive annular source at different temperatures in situ. Temperature change occurred between 50 °C and 400 °C. L X-ray emission spectra were obtained by using a solid-state Si(Li) X-ray detector. L X-ray production cross sections, intensity ratios, and full-width half maximum (FWHM) values for the compounds were determined by evaluating the emission spectra varying with the temperature. According to the results obtained, it was observed that Lβ1 X-rays were less influenced in comparison with Lα X-rays while Lα X-rays were also less influenced in comparison with Lβ2 X-rays.

Photon-Induced L-Shell X-Ray Production Cross Sections for Lanthanides at 59.54 keV

2017 ◽  
Vol 890 ◽  
pp. 223-226 ◽  
Author(s):  
Rıdvan Durak ◽  
Ferdi Akman ◽  
Abdulhalik Karabulut
Keyword(s):  
High Resolution ◽  
Cross Sections ◽  
Production Cross ◽  
Theoretical Data ◽  
Experimental Results ◽  
X Rays ◽  
X Ray ◽  
Reflection Geometry ◽  
Experimental Values ◽  
Annular Source

The Ll, Lα and Lβ X-ray production cross sections for Pr, Nd, Sm, Eu, Gd and Tb elements were determined using a reflection geometry. The excitation was performed with a 241Am radioactive annular source and the L X-rays emitted from targets were counted with a high-resolution Si (Li) detector. The experimental values were compared with other available experimental results and theoretical data. An agreement is observed between the measured and other experimental results or theoretical data.

Determination of K shell absorption parameters for some lanthanides using the X-ray attenuation method

2015 ◽  
Vol 93 (12) ◽  
pp. 1532-1540 ◽  
Author(s):  
F. Akman ◽  
R. Durak ◽  
M.R. Kaçal
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Experimental Results ◽  
Secondary Source ◽  
X Rays ◽  
Strength Parameters ◽  
X Ray ◽  
Total Attenuation ◽  
First Time

The total attenuation cross section at the K edge, absorption jump ratio, jump factor, Davisson–Kirchner ratio, and oscillator strength parameters for the K shell were determined by measuring the total attenuation cross sections around the K edge for Pr, Nd2O3, and Sm. The measurements were performed in a secondary excitation geometry using the Kα2, Kα1, Kβ1, and Kβ2 X-rays (in the region from 31.817 to 55.293 keV) from different secondary source targets excited by the 59.54 keV γ-photons from an 241Am annular source. It is the first time that the Davisson–Kirchner ratio values have been determined for present samples. The experimental results were compared with the theoretically calculated and other available experimental results.

X-RAY PRODUCTION, INNER SHELL IONIZATION AND READING’S THEOREM IN ION · ATOM COLLISIONS

1992 ◽  
Vol 02 (03) ◽  
pp. 197-209
Author(s):  
KEIZO ISHII
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Production Cross ◽  
X Rays ◽  
Ionization Cross ◽  
Heavy Charged Particles ◽  
X Ray ◽  
Inner Shell Ionization ◽  
Ionization Cross Sections ◽  
Shell Ionization

When a solid or gaseous target is bombarded with heavy charged particles, inner shell electrons of target atoms are ionized and characteristic x rays are produced. We can easily observe these x rays with a Si(Li) detector and derive inner-shell ionization cross section from the x-ray production cross sections. In this paper, we make a review of x-ray production, inner shell ionization and Reading’s theorem in light ion·atom collisions. This theorem is one of the most important ones in the ion·atom collision physics and permits precise discussion on comparison between experimental inner-shell ionization cross sections obtained with a Si(Li) detector and the calculations based on usual theories where the incident particle is assumed to interact with only one electron in an atom and the presence of other electrons is ignored.

K X-ray fluorescence parameters of peripherally and non-peripherally tetra-substituted zinc (II) phthalocyanines

2017 ◽  
Vol 95 (2) ◽  
pp. 125-129 ◽  
Author(s):  
Erhan Cengiz ◽  
Muhammet Dogan ◽  
Zekeriya Biyiklioglu ◽  
Dilek Cakir ◽  
Engin Tirasoglu ◽  
...  
Keyword(s):  
Cross Sections ◽  
Production Cross ◽  
X Rays ◽  
Pure Zinc ◽  
X Ray ◽  
Fluorescence Parameters ◽  
Zinc Phthalocyanines ◽  
Γ Rays ◽  
Experimental Values ◽  
Shell Production

The K shell production cross-sections and Kβ to Kα X-ray intensity ratios of peripherally and non-peripherally tetra-substituted zinc (II) phthalocyanine complexes were determined using energy dispersive X-ray fluorescence spectrometry (EDXRF). The effect of substituent position on these parameters was also investigated. The complexes were excited by 59.5 keV γ-rays from an 241Am annular radioactive source and K X-rays emitted by the complexes were counted by an Ultra-LEGe detector with a resolution of 150 eV at 5.9 keV. The experimental results of the zinc phthalocyanines having the same ligand substituted peripheral and non-peripheral were compared with each other, theoretical, and experimental values of pure zinc.

Measurement of Li X-ray fluorescence production cross sections and intensity ratios of some elements at 59.54 keV

2015 ◽  
Vol 93 (10) ◽  
pp. 1057-1066 ◽  
Author(s):  
F. Akman ◽  
R. Durak ◽  
M.R. Kaçal ◽  
M.F. Turhan
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Reasonable Agreement ◽  
Production Cross ◽  
Radioactive Source ◽  
Experimental Results ◽  
X Ray ◽  
Intensity Ratios ◽  
Theoretical Results ◽  
Excitation Geometry

The Li (i = l, α, β, γ) X-ray production cross section and Lα/Ll, Lα/Lβ, Lα/Lγ, Ll/Lβ, Ll/Lγ, and Lβ/Lγ intensity ratio values for Yb, Ta, W, Hg, Tl, Pb, Bi, Th, and U have been determined using an excitation geometry at 59.54 keV incident photon energy. The measurements were performed using an Am-241 annular radioactive source and a high resolution Si(Li) detector. The experimental results of Li X-ray production cross sections and intensity ratios were compared with three different theoretical results and other available experimental results in the literature. Reasonable agreement is typically observed between the present and theoretical results.

scholarly journals M sub-shell X-ray fluorescence cross-section measurements in high Z elements with X-ray tube photon source

2014 ◽  
Vol 5 (2) ◽  
pp. 363-369 ◽  
Author(s):  
Sheenu Gupta ◽  
Gurpreet Kaur ◽  
Himani Bansal ◽  
Vijay Kumar Mittal ◽  
Raj Mittal
Keyword(s):  
Cross Section ◽  
X Ray ◽  
Fluorescence Cross Section ◽  
Photon Source

Measurements of radiative vacancy transfer probabilities from L3 subshell to M and N subshells of Sm and Eu in halogen compounds

2018 ◽  
Vol 96 (2) ◽  
pp. 202-207
Author(s):  
B.G. Durdu
Keyword(s):  
X Rays ◽  
X Ray ◽  
Halogen Compounds ◽  
Radioisotope Source ◽  
Γ Rays ◽  
Intensity Ratios ◽  
Experimental Values

The radiative vacancy transfer probabilities from the L3 subshell to the M and N subshells for Sm and Eu and their compounds have been measured using L shell fluorescence yields and X-ray intensity ratios. The samples were excited by 59.5 keV γ-rays, which were emitted from an Am-241 radioisotope source. The L X-rays emitted from samples were counted by a Si(Li) detector with a resolution of 155 eV at 5.9 keV. The experimental values were compared with the calculated theoretical values for pure Sm and Eu.

Influence of X-Ray Induced Fluorescence on Energy Dispersive X-Ray Analysis of Thin Foils

1977 ◽  
Vol 35 ◽  
pp. 328-329
Author(s):  
E. A. Kenik ◽  
J. Bentley
Keyword(s):  
Thin Foil ◽  
Electron Excitation ◽  
Simple Approach ◽  
Foil Thickness ◽  
X Rays ◽  
X Ray ◽  
Hole Spectrum ◽  
Illumination System ◽  
Thin Foils ◽  
Intensity Ratios

Cliff and Lorimer (1) have proposed a simple approach to thin foil x-ray analy sis based on the ratio of x-ray peak intensities. However, there are several experimental pitfalls which must be recognized in obtaining the desired x-ray intensities. Undesirable x-ray induced fluorescence of the specimen can result from various mechanisms and leads to x-ray intensities not characteristic of electron excitation and further results in incorrect intensity ratios.In measuring the x-ray intensity ratio for NiAl as a function of foil thickness, Zaluzec and Fraser (2) found the ratio was not constant for thicknesses where absorption could be neglected. They demonstrated that this effect originated from x-ray induced fluorescence by blocking the beam with lead foil. The primary x-rays arise in the illumination system and result in varying intensity ratios and a finite x-ray spectrum even when the specimen is not intercepting the electron beam, an ‘in-hole’ spectrum. We have developed a second technique for detecting x-ray induced fluorescence based on the magnitude of the ‘in-hole’ spectrum with different filament emission currents and condenser apertures.

Studies of metaphase chromosomes in the scanning transmission x-ray microscope: Image fidelity, radiation damage and specimen preparation

1992 ◽  
Vol 50 (2) ◽  
pp. 1038-1039
Author(s):  
Shawn Williams ◽  
Xiaodong Zhang ◽  
Susan Lamm ◽  
Jack Van’t Hof
Keyword(s):  
Visible Light ◽  
Radiation Damage ◽  
Cross Section ◽  
Imaging Techniques ◽  
Dose Range ◽  
Specimen Preparation ◽  
X Rays ◽  
Metaphase Chromosomes ◽  
X Ray ◽  
Scanning Transmission

The Scanning Transmission X-ray Microscope (STXM) is well suited for investigating metaphase chromosome structure. The absorption cross-section of soft x-rays having energies between the carbon and oxygen K edges (284 - 531 eV) is 6 - 9.5 times greater for organic specimens than for water, which permits one to examine unstained, wet biological specimens with resolution superior to that attainable using visible light. The attenuation length of the x-rays is suitable for imaging micron thick specimens without sectioning. This large difference in cross-section yields good specimen contrast, so that fewer soft x-rays than electrons are required to image wet biological specimens at a given resolution. But most imaging techniques delivering better resolution than visible light produce radiation damage. Soft x-rays are known to be very effective in damaging biological specimens. The STXM is constructed to minimize specimen dose, but it is important to measure the actual damage induced as a function of dose in order to determine the dose range within which radiation damage does not compromise image quality.

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