scholarly journals Cross section and neutron angular distribution measurements of neutron scattering on natural iron

2019 ◽  
Vol 99 (2) ◽  
Author(s):  
E. Pirovano ◽  
R. Beyer ◽  
M. Dietz ◽  
A. R. Junghans ◽  
S. E. Müller ◽  
...  
Keyword(s):  
Angular Distribution ◽  
Neutron Scattering ◽  
Cross Section ◽  
Natural Iron ◽  
Neutron Angular Distribution

scholarly journals Analyzing the neutron scattering angular distribution in a ACE-formatted multigroup cross section library using the maximum entropy method

2020 ◽  
Vol 239 ◽  
pp. 10003
Author(s):  
Shuai-tao ZHU ◽  
Xu-bo MA ◽  
Hui TANG ◽  
Le YANG ◽  
Bo CAO
Keyword(s):  
Angular Distribution ◽  
Neutron Scattering ◽  
Maximum Entropy ◽  
Cross Section ◽  
Maximum Entropy Method ◽  
Entropy Method ◽  
Scattering Data ◽  
Angle Data ◽  
Calculation Results ◽  
Angle Method

To describe the angular distribution for a group-to-group neutron scattering event, the coefficients of a truncated Legendre polynomial are usually used in the multigroup cross section. However, the truncated expansion can caused negative values of a probability density function (PDF) in some scattering angles. In this study, the PDF of scattering angles is calculated using the maximum entropy method to avoid the negative probabilities of some scattering angles and the multigroup cross section library in ACE format is generated. The multigroup cross section library is verified by the computation of RBEC-M benchmark using RMC. The differences between two methods generating scattering data, the maximum entropy method and discrete angle method, are also discussed. The calculation results using multigroup cross section library in ACE format are well good agreement with the results of benchmark report. It shows that multigroup cross section library including the scattering angle data computed by the maximum entropy method is corrected and can be used for Monte Carlo calculation.

scholarly journals On the scattering of fast neutrons by protons

1947 ◽  
Vol 191 (1025) ◽  
pp. 195-209 ◽  
Keyword(s):  
Angular Distribution ◽  
Cross Section ◽  
Cosmic Ray ◽  
Fast Neutrons ◽  
Meson Mass ◽  
Nuclear Forces ◽  
Total Scattering ◽  
Empirical Results ◽  
Meson Theory ◽  
Total Scattering Cross Section

The features of the scattering of fast neutrons by protons are calculated using the Møller- Rosenfeld version of the meson theory of nuclear forces. The experimental results of Occhialini & Powell are used to check the predicted angular distribution of the scattered particles and to determine the mass of the meson; the meson mass indicated is about 215 electronic masses, which agrees with the mass of cosmic ray mesons. The total scattering cross-section predicted by the theory agrees with the empirical results.

Evidence for the Photoemission Nature of Gd 4f Resonant Photoemission

1998 ◽  
Vol 524 ◽  
Author(s):  
S. R. Mishra ◽  
T. R. Cummins ◽  
W. J. Gammon ◽  
G. D. Waddill ◽  
G. Van der-Laan ◽  
...  
Keyword(s):  
Angular Distribution ◽  
Cross Section ◽  
Photon Energy ◽  
Photoelectron Spectroscopy ◽  
Emission Cross Section ◽  
Linear Dichroism ◽  
Constructive Interference ◽  
Resonant Photoemission ◽  
Magnetic Linear Dichroism ◽  
Spectroscopy Experiment

ABSTRACTThe constructive interference between direct and indirect channels above the absorption threshold of a core level leads to a massive increase in the emission cross section leading to a phenomenon called “resonant photoemission”. Using novel magnetic linear dichroism in angular distribution photoelectron spectroscopy experiment we have tried to understand the nature of the resonant photoemission process in Gd metal. The presence of dichroism in Gd 4f photoemission intensity at a photon energy corresponding to resonant photoemission clearly demonstrates the photoemission-like nature of the resonant photoemission process.

scholarly journals The investigation of Neutron Scattering In Spin Waves Theory of Ferromagnetic Crystals

2014 ◽  
Vol 8 (4) ◽  
Author(s):  
Azadeh Farzaneh ◽  
Mohammad Reza Abdi ◽  
Khadije Rezaee Ebrahim Saraee
Keyword(s):  
Neutron Scattering ◽  
Spin Wave ◽  
Cross Section ◽  
Inelastic Neutron Scattering ◽  
Spin Waves ◽  
Wave Theory ◽  
Spin Correlation ◽  
Inelastic Neutron ◽  
Magnetic Behaviour ◽  
Spin Interaction

Inelastic neutron scattering, probing the temporal spin-spin correlation at the different microscopic scale, is a powerful technique to study the magnetic behaviour of ferromagnetic crystals. In addition, high penetration power of neutron in samples has made it as a useful way for spin-spin interaction in neutron scattering. Changes in the magnetic cross section in term of different energy transfer and temperatures are calculated for nickel and iron as transition metals in Heisenberg model versus spin wave theory by considering atomic form factor. Finally, the effect of magnetic structure and behaviour of crystal in measuring cross-section shows that increasing temperature results in the Cross-section increase Also, the existence of propagating spin waves below Tc is compared in Ni and Fe in different momentum transfers. The relation of spin wave energy with temperature dependence of nickel has created different behaviour in the changes of cross section rather than iron.

scholarly journals p-Wave Strength in the Low-energy 7Li(p,?0)8Be Cross Section

1995 ◽  
Vol 48 (5) ◽  
pp. 813 ◽  
Author(s):  
FC Barker
Keyword(s):  
Angular Distribution ◽  
Shell Model ◽  
Cross Section ◽  
Low Energy ◽  
P Wave ◽  
Model Calculations ◽  
Energy Data

Recent fits to low-energy 7Li(p, "Yo)8Be angular distribution and analysing power data suggested a large p-wave strength. It is shown that acceptable fits to the data can be obtained by attributing the p-wave Ml contributions to the tails of the 17 �64 and 18 �15 MeV 1+ levels of 8Be, with p-wave strengths much less than those obtained previously, but only if some of the spectroscopic amplitudes have signs opposite to those suggested by shell model calculations and/or a fit to higher-energy data.

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