Absolute inner-shell cross section determination for EELS analysis

1988 ◽  
Vol 46 ◽  
pp. 534-535
Author(s):  
P.A. Crozier
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Absolute Cross Section ◽  
Specimen Thickness ◽  
Mass Thickness ◽  
Scattering Cross ◽  
Before And After ◽  
Estimated Error ◽  
Scattering Cross Sections ◽  
Electron Microscopist

Absolute inelastic scattering cross sections or mean free paths are often used in EELS analysis for determining elemental concentrations and specimen thickness. In most instances, theoretical values must be used because there have been few attempts to determine experimental scattering cross sections from solids under the conditions of interest to electron microscopist. In addition to providing data for spectral quantitation, absolute cross section measurements yields useful information on many of the approximations which are frequently involved in EELS analysis procedures. In this paper, experimental cross sections are presented for some inner-shell edges of Al, Cu, Ag and Au.Uniform thin films of the previously mentioned materials were prepared by vacuum evaporation onto microscope cover slips. The cover slips were weighed before and after evaporation to determine the mass thickness of the films. The estimated error in this method of determining mass thickness was ±7 x 107g/cm2. The films were floated off in water and mounted on Cu grids.

Ion Beam Analysis of O, N, and B Compositions in Materials Using Non-Rutherford Scattering of Protons

1988 ◽  
Vol 128 ◽  
Author(s):  
N. R. Parikh ◽  
Z. H. Zhang ◽  
M. L. Swanson ◽  
N. Yu ◽  
W. K. Chu
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Ion Beam ◽  
Proton Scattering ◽  
Light Elements ◽  
Ion Scattering ◽  
Scattering Cross ◽  
Beam Analysis ◽  
Rutherford Scattering ◽  
Scattering Cross Sections

ABSTRACTElastic scattering of protons with energies from 1.5 MeV to 2 MeV was used to determine the concentration of oxygen in Y-Ba-Cu-O compound, nitrogen in GaN films, and boron in B-Si glass and other materials. Proton scattering from light elements in this energy range exhibits non-Rutherford scattering cross section, which are enhanced by a factor of 3 to 6 or more relative to the Rutherford scattering cross sections. Thus the sensitivity for the light clement detection is considerably larger than that obtained by He ion scattering.Quantitative analysis by proton scattering is discussed and compared with other methods.

Acoustic Scattering Cross Sections of Smart Obstacles: A Case Study

2011 ◽  
Vol 10 (3) ◽  
pp. 672-694
Author(s):  
Lorella Fatone ◽  
Maria Cristina Recchioni ◽  
Francesco Zirilli
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Space Shuttle ◽  
Scattering Problem ◽  
Plane Waves ◽  
Acoustic Scattering ◽  
Scattering Cross Section ◽  
Scattering Cross ◽  
Scattering Cross Sections

AbstractAcoustic scattering cross sections of smart furtive obstacles are studied and discussed. A smart furtive obstacle is an obstacle that, when hit by an incoming field, avoids detection through the use of a pressure current acting on its boundary. A highly parallelizable algorithm for computing the acoustic scattering cross section of smart obstacles is developed. As a case study, this algorithm is applied to the (acoustic) scattering cross section of a “smart” (furtive) simplified version of the NASA space shuttle when hit by incoming time-harmonic plane waves, the wavelengths of which are small compared to the characteristic dimensions of the shuttle. The solution to this numerically challenging scattering problem requires the solution of systems of linear equations with many unknowns and equations. Due to the sparsity of these systems of equations, they can be stored and solved using affordable computing resources. A cross section analysis of the simplified NASA space shuttle highlights three findings: i) the smart furtive obstacle reduces the magnitude of its cross section compared to the cross section of a corresponding “passive” obstacle; ii) several wave propagation directions fail to satisfactorily respond to the smart strategy of the obstacle; iii) satisfactory furtive effects along all directions may only be obtained by using a pressure current of considerable magnitude. Numerical experiments and virtual reality applications can be found at the website: http://www.ceri.uniromal.it/ceri/zirilli/w7.

scholarly journals Analysis of the time-of-flight neutron scattering cross-section data for light water measured at the SEQUOIA spectrometer, Spallation Neutron Source (SNS)

2020 ◽  
Vol 239 ◽  
pp. 14007
Author(s):  
Vaibhav Jaiswal ◽  
Luiz Leal ◽  
Alexander I. Kolesnikov
Keyword(s):  
Cross Section ◽  
High Temperatures ◽  
Cross Sections ◽  
Scattering Cross Section ◽  
Spallation Neutron Source ◽  
Light Water ◽  
Section Data ◽  
Scattering Cross ◽  
Thermal Scattering ◽  
Scattering Cross Sections

Thermal neutron scattering cross-section data for light water available in the major nuclear data libraries observes significant differences especially at reactor operating temperatures. During the past few years there has been a renewed interest in reviewing the existing thermal scattering models and generating more accurate and reliable thermal scattering cross sections using existing experimental data and in some cases based on Molecular Dynamics (MD) simulations. There is a need for performing new time-of-flight experiments at high temperatures and pressures, to have a better understanding of the physics involved in the scattering process that could help improve the existing TSL data. Lack of experimental thermal scattering data for light water at high temperatures led to a new measurement campaign within the INSIDER project at the Institut de radioprotection et de sûreté nucléaire (IRSN). Double differential scattering cross section for light water have been measured at the SEQUOIA spectrometer based at the Spallation Neutron Source (SNS), Oak Ridge National Laboratory, United States. Several measurements have been carried out at different temperatures and pressures corresponding to liquid light water. Measurements at five different incident neutron energies Ei (8, 60, 160, 280 and 800 meV) have been carried out to help exploring different regions of the frequency spectrum. This paper presents the analysis of the dynamic structure factor and the derived frequency spectrum of light water. The analysis of the experimental data would provide one with better confidence, the behavior of thermal scattering cross sections for light water at high temperatures, knowledge of which is very important for the design of novel reactors as well as existing pressurized water reactors.

Modification of scattering of waves by central loading

1968 ◽  
Vol 46 (24) ◽  
pp. 2755-2763 ◽  
Author(s):  
Chin-Lin Chen
Keyword(s):  
Plane Wave ◽  
Cross Section ◽  
Cross Sections ◽  
Normal Incidence ◽  
Physical Explanation ◽  
Lumped Element ◽  
Scattering Cross ◽  
Back Scattering ◽  
Conducting Wire ◽  
Scattering Cross Sections

The problem of the scattering of a plane wave by a long, thin, perfectly conducting wire is studied. The scatterer is loaded at its center by a lumped element. The effects of the loading on the scattering of waves are investigated. Numerical results are obtained for the case of normal incidence. The results show that for relatively short wires, the back-scattering cross sections may be modified effectively by central loading, while for longer wires, the modification is rather difficult to achieve. To nullify the back-scattering cross section completely, it is necessary to use active loading if kh > 3.6. A physical explanation is also presented.

scholarly journals Positron interactions with nitrogen and oxygen molecules: elastic, inelastic and total cross sections

2019 ◽  
Vol 73 (12) ◽  
Author(s):  
Lilian Ellis-Gibbings ◽  
Francisco Blanco ◽  
Gustavo García
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Impact Energy ◽  
Optical Theorem ◽  
Calculation Methods ◽  
Positron Scattering ◽  
Total Cross Sections ◽  
Scattering Cross ◽  
Simple Molecules ◽  
Scattering Cross Sections

Abstract Positron scattering cross sections, used for modelling particle transport in various media, are difficult to gather experimentally. As such, various cross section calculation methods have been developed to varying accuracy. The IAM-SCAR+I method has been improved upon recently to fulfil the optical theorem and the results for two important simple molecules, N2 and O2, are presented here. These results are compared to literature and our findings are comparable in most impact energy ranges. Graphical abstract

Measurement of the total cross section of titanium with neutrons of 6–8 m/s

1982 ◽  
Vol 60 (5) ◽  
pp. 632-635 ◽  
Author(s):  
P. Gabriel ◽  
J. M. Robson
Keyword(s):  
Total Cross Section ◽  
Inelastic Scattering ◽  
Thermal Neutron ◽  
Cross Section ◽  
Cross Sections ◽  
Scattering Cross ◽  
Scattering Cross Sections ◽  
Inverse Velocity

The sum of the absorption, incoherent, and thermal inelastic scattering cross sections of natural titanium has been measured at 293 K for three neutron velocities in the range 6–8 m/s. They agree with values to be expected on the basis of an inverse velocity extrapolation from measurements near thermal neutron velocities.

POLARIZED AND UNPOLARIZED INCLUSIVE ELECTRON SCATTERING IN NUCLEI AND THE INCLUSIVE NEUTRINO CROSS-SECTION

1995 ◽  
Vol 04 (01) ◽  
pp. 163-179
Author(s):  
S.L. MINTZ ◽  
M. POURKAVIANI
Keyword(s):  
Cross Section ◽  
Electron Scattering ◽  
Cross Sections ◽  
Inelastic Electron ◽  
Nuclear Excitation ◽  
Scattering Cross ◽  
Neutrino Cross Section ◽  
Inclusive Electron ◽  
Scattering Cross Sections ◽  
The Relationship

The unpolarized and parity violating polarized inclusive inelastic electron scattering cross-sections are calculated for incident electrons from threshold to 100 MeV, for the 12C nucleus. The relationship between these cross-sections and the inclusive neutrino cross-section on this same nucleus is discussed. The possibility of using the parity violating polarized electron scattering interaction to obtain the average nuclear excitation is also discussed.

scholarly journals Making baryons dark: variation of cross section with approach to equilibrium

2015 ◽  
Vol 11 (A29B) ◽  
pp. 739-739
Author(s):  
Allan D Ernest ◽  
Matthew P. Collins
Keyword(s):  
Quantum Theory ◽  
Cross Section ◽  
Cross Sections ◽  
Galactic Halos ◽  
Approach To Equilibrium ◽  
Scattering Cross ◽  
Scattering Cross Sections

AbstractWe show that as equilibrium is approached in deep gravity wells, such as those of galactic halos, gravitational quantum theory predicts that radial particle densities ρ(r) tend toward 1/r2 profiles, and photon-baryon scattering cross sections are significantly reduced.

scholarly journals On the role of longitudinal momenta in high energy hadron-hadron scattering

Open Physics ◽  
2012 ◽  
Vol 10 (4) ◽  
Author(s):  
Igor Sharf ◽  
Andrii Tykhonov ◽  
Grygorii Sokhrannyi ◽  
Maksym Deliyergiyev ◽  
Natalia Podolyan ◽  
...  
Keyword(s):  
Inelastic Scattering ◽  
Cross Section ◽  
Cross Sections ◽  
High Energy ◽  
Momentum Conservation ◽  
Scattering Cross ◽  
Energy Hadron ◽  
Scattering Cross Sections ◽  
Energy Momentum Conservation

AbstractWe demonstrate a new method to calculate inelastic scattering cross-sections, which in contrary to the Regge-based methods takes into account the energy momentum conservation law. It is shown that the main contribution to integral expressing inelastic scattering cross-sections does not come from the multi-Regge domain. In particular, accounting for the longitudinal momenta contribution to virtualities is sufficient and results in the new mechanism of cross-section growth. The reasons for taking into account the sufficiently high number of interference contributions are shown and the approximate method for this purpose is developed. By fitting single free parameter of the model achieved a qualitative agreement of the total and inelastic cross sections with experimental data.

scholarly journals A PRACTICAL EFFECT OF THE RECENT O16 CROSS SECTION AND MUBAR UNCERTAINTIES

2021 ◽  
Vol 247 ◽  
pp. 15010
Author(s):  
D. Kent Parsons ◽  
Scott A. Turner ◽  
Peter J. Jaegers
Keyword(s):  
Elastic Scattering ◽  
Cross Section ◽  
Cross Sections ◽  
Neutron Transport ◽  
Surprising Result ◽  
Typical Application ◽  
Scattering Cross ◽  
Practical Effect ◽  
Fission Neutrons ◽  
Scattering Cross Sections

With the recent release of ENDF/B VIII.0 data, additional covariance data was provided for many isotopes, including O16. The detail of elastic scattering and mubar covariance data for O16 increased dramatically between ENDF/B VII.1 and ENDF/B VIII.0. This new covariance data has been processed with NJOY2016 and investigation has begun on the effects of these new uncertainty data. The uncertainties are applied to multi-group scattering cross sections and P1 Legendre components in deterministic neutron transport. A simple but typical application of shielding fission neutrons with concrete has been used to assess the practical effects of the new covariance data for O16. A somewhat surprising result is that the mubar uncertainty can have a significant effect on the calculated shielding and criticality results.

Sign in / Sign up

Export Citation Format

Share Document