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.

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.

A ALow-Energy Direct Channel Regge-pole Approach to α-C12Elastic Scattering .I

1981 ◽  
Vol 36 (5) ◽  
pp. 443-446 ◽  
Author(s):  
D. Majumdar ◽  
A. Roy Chowdhury ◽  
T. Roy
Keyword(s):  
Elastic Scattering ◽  
Compound Nucleus ◽  
Cross Sections ◽  
Regge Pole ◽  
Direct Channel ◽  
Scattering Cross ◽  
Scattering Cross Sections ◽  
Background Effect

Abstract Differential scattering cross-sections for the elastic scattering of α by C12 at laboratory bombarding energies from 11.0 to 16.0 MeV have been evaluated in the direct channel Regge-pole formalism, taking into account the contributions from a few nearby dominant excited levels of the compound nucleus O16 and incorporating the background effect. The relevant pole-parameters have also been predicted.

Differential cross-section measurements in positron–argon collisions

1996 ◽  
Vol 74 (7-8) ◽  
pp. 505-508 ◽  
Author(s):  
R. M. Finch ◽  
Á. Kövér ◽  
M. Charlton ◽  
G. Laricchia
Keyword(s):  
Elastic Scattering ◽  
Differential Cross Section ◽  
Inelastic Scattering ◽  
Energy Range ◽  
Cross Section ◽  
Cross Sections ◽  
Differential Cross ◽  
Coupling Effect ◽  
Channel Coupling ◽  
Scattering Cross

Differential cross sections for elastic scattering and ionization in positron–argon collisions as a function of energy (40–150 eV) are reported at 60°. Of particular interest is the energy range 55–60 eV, where earlier measurements by the Detroit group found a drop in the elastic-scattering cross section of a factor of 2. This structure has been tentatively attributed to a cross channel-coupling effect with an open inelastic-scattering channel, most likely ionization. Our results indicate that ionization remains an important channel over the same energy range and only begins to decrease at an energy above 60 eV.

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.

Accurate elastic scattering cross sections for 17-MeV deuterons

1974 ◽  
Vol 10 (1) ◽  
pp. 217-230 ◽  
Author(s):  
J. D. Childs ◽  
W. W. Daehnick ◽  
M. J. Spisak
Keyword(s):  
Elastic Scattering ◽  
Cross Sections ◽  
Scattering Cross ◽  
Scattering Cross Sections
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