scholarly journals The low-energy 9Be(g, n)8Be cross section.

2000 ◽  
Vol 53 (2) ◽  
pp. 247 ◽  
Author(s):  
F. C. Barker
Keyword(s):  
Cross Section ◽  
Radioactive Isotope ◽  
Low Energy ◽  
Inelastic Electron ◽  
R Matrix ◽  
Section Data ◽  
Isotope Data ◽  
Particle Potential ◽  
The Difference ◽  
Parameter Values

Fits are made to low-energy 9 Be(g;n) 8 Be cross-section data using one-level R-matrix formulae including channel contributions. Fits with reasonable parameter values are found for the newer radioactive-isotope data, and also for data obtained from inelastic electron scattering on 9 Be, but not for older radioactive-isotope data. This differs from the result of recent fits using a semi-microscopic model, which supported the older data. The difference is attributed to the use in the latter calculation of a single-particle potential description of the continuum wave function.

scholarly journals 8Be Level Properties from the Low-energy 7Li(p, γo)8Be Cross Section

1996 ◽  
Vol 49 (6) ◽  
pp. 1081 ◽  
Author(s):  
FC Barker
Keyword(s):  
Shell Model ◽  
Cross Section ◽  
Low Energy ◽  
Cross Section Data ◽  
Model Calculations ◽  
R Matrix ◽  
Section Data ◽  
Extensive Data

R-matrix fits to 7Li(p, γo)8Be cross section data for Ep ≤ 1500 keV give reduced width amplitudes of the 1+ levels of 8Be at 17.64 and 18.15 MeV having signs in agreement with shell model calculations, contrary to previous fits to less-extensive data.

The Development and Validation of Nuclear Cross Section Processing Code for Reactor-RXSP

2013 ◽  
Author(s):  
Jiankai Yu ◽  
Songyang Li ◽  
Kan Wang ◽  
Guanbo Wang ◽  
Ganglin Yu
Keyword(s):  
Cross Section ◽  
Nuclear Data ◽  
Original Data ◽  
Data File ◽  
Cross Section Data ◽  
Reactor Physics ◽  
R Matrix ◽  
Section Data ◽  
Nuclear Cross Section ◽  
Long Time

The accuracy of the nuclear cross section data is a prerequisite for the accuracy of reactor physics calculations. The RXSP(Reactor Cross Section Processing Code) which is developed by REAL (Reactor Engineering Analysis Laboratory) of Department of Engineering Physics in Tsinghua University, has changed the situation in China that nuclear cross section processing has been dependent of NJOY for a long time. The key methods such as fast Doppler broadening, thermal libraries interpolation, and OpenMP parallel acceleration, can be achieved with RXSP. This code is able to process the original data of ENDF/B (Evaluated Nuclear Data File/B) efficiently and accurately to produce the continuous energy point cross section data which is necessary for RMC. By comparing with NJOY, The microscopic and macroscopic verification shows that RXSP has the same accuracy as NJOY while RXSP has saved greatly the processing time to meet the efficient demand in the frequent reactor physics-thermal-hydraulic coupling calculations to solve the complex questions related on a large number of materials and temperature. In addition, RXSP make it available to process the resonance parameters of the R-matrix Limited format.

Evaluation of Low-Energy Cross Section Data for U233

1960 ◽  
Vol 8 (1) ◽  
pp. 66-82 ◽  
Author(s):  
J. E. Evans ◽  
R. G. Fluharty
Keyword(s):  
Cross Section ◽  
Low Energy ◽  
Cross Section Data ◽  
Section Data

scholarly journals Neutron capture cross section of 185Re leading to ground and isomer states of 186Re in the keV-neutron energy region

2018 ◽  
Vol 178 ◽  
pp. 03005
Author(s):  
T. Katabuchi ◽  
K. Takebe ◽  
S. Umezawa ◽  
R. Fujioka ◽  
T. Saito ◽  
...  
Keyword(s):  
Cross Section ◽  
Neutron Capture ◽  
Energy Region ◽  
Capture Cross Section ◽  
Production Cross ◽  
Pulse Height ◽  
Capture Cross ◽  
Neutron Capture Cross Section ◽  
Section Data ◽  
The Difference

The neutron capture cross section of 185Re was measured in the astrophysically important energy region. Measurements were made using a neutron beam from a 7Li(p,n)7Be neutron source with energies ranging from 3 to 90 keV. Two different experimental techniques, time-of-flight (TOF) and activation methods, were employed. In the TOF experiments, the total neutron capture cross section of 185Re was determined by the pulse-height weighting technique. In the activation method, the partial capture cross section leading to the ground state of 186Re was measured by detecting decay γ-rays from neutron activated samples. The present cross section values were compared with evaluated cross section data and previous measurements. The difference between the TOF and activation results was smaller than experimental uncertainties. This suggests that the production cross section of isomer states of 186Re is very small.

Resonance Widths and Unitarity

1972 ◽  
Vol 50 (2) ◽  
pp. 84-92 ◽  
Author(s):  
C. T. Tindle
Keyword(s):  
Energy Dependence ◽  
Cross Section ◽  
Matrix Theory ◽  
Neutron Cross Section ◽  
Matrix Formalism ◽  
R Matrix ◽  
Level Width ◽  
S Matrix ◽  
The Difference ◽  
Energy Dependent

The low energy neutron cross section of 135Xe is analyzed using both the R-matrix theory of Wigner and Eisenbud and the S-matrix theory of Humblet and Rosenfeld. Particular attention is given to the role played by the total resonance level width for it is well known that the R-matrix widths are energy dependent but the S-matrix widths are not. This different energy dependence leads to different analytic forms for the cross section and the n + 135Xe reaction offers what may be the simplest and best physical example for comparing these two forms. To the accuracy of the present data the difference is not detectable. The different energy dependence of the resonance widths is shown to be related to unitarity. A general proof that the R-matrix formalism is always unitary is given. The difficulty of satisfying unitarity in the S-matrix formalism is discussed and it is shown for the n + 135Xe reactions that this can lead to physically unacceptable solutions. This "lack of unitarity" does not, however, lead to any difficulties in fitting the present experimental data.

Radiative capture of proton by 9Be(p, γ)10B at low energy.

2022 ◽  
Author(s):  
Abdul Kabir ◽  
Jameel-Un Nabi
Keyword(s):  
Cross Section ◽  
Capture Cross Section ◽  
Radiative Capture ◽  
Potential Model ◽  
Low Energy ◽  
Capture Cross ◽  
Zero Energy ◽  
R Matrix ◽  
S Factor ◽  
Radiative Capture Cross Section

Abstract Radiative capture p+9Be → 10B+γ at energies bearing astrophysical importance is a key process for the spectroscopic study of 10B. In this work, we consider the radiative capture cross-section for the 9Be(p, γ)10B within the framework of the potential model and the R-matrix method for the multi-entrance channel cases. In certain cases, when the potential fails, therefore, the R-matrix approach is better to use for the description of partial components of the cross-section that have sharp or broad resonances. For all possible electric and magnetic dipole transitions, partial components of the astrophysical S-factor are computed. The computed value of the total S-factor at zero energy is consistent with the reported results.

scholarly journals ELASTIC BACKSCATTERED CROSS-SECTIONS OF 14N(P,P0)14N AT HIGH ANGLES

2020 ◽  
Vol 20 (3) ◽  
pp. 749-754
Author(s):  
MOHAMED ELTAYEB M. EISA ◽  
JOHAN ANDRE MARS ◽  
MUSTAFA J. ABUALREISH ◽  
MARWA L. WAREGH
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Ion Beam ◽  
Region Of Interest ◽  
Laboratory Frame ◽  
Matrix Formalism ◽  
Cross Section Data ◽  
R Matrix ◽  
Section Data ◽  
Elastic Backscattering

The importance and present needs of proton cross section data of nitrogen needed by the Ion Beam Analysis (IBA) community are briefly reviewed. Previous experimental data presently used for the theoretical determination of the proton cross-sections are discussed. The Azure code based on the R-matrix formalism was then used to evaluate the data and to determine the nitrogen cross section in the previous and presently desired angular domain and energy region of interest. The experimental elastic backscattering cross section data, as spectra, for back-scattering analysis determined at angles in the laboratory frame of reference, θi,lab, of 165o, 170o and 176o are presented.

scholarly journals The Regge Pole Model and Forward Elastic Data at High Energies ? An Analysis

1981 ◽  
Vol 34 (6) ◽  
pp. 611
Author(s):  
Mujahid Kamran
Keyword(s):  
Cross Section ◽  
Regge Pole ◽  
Pole Model ◽  
Exchange Degeneracy ◽  
Cross Section Data ◽  
Regge Pole Model ◽  
Section Data ◽  
High Energies ◽  
Elastic Data ◽  
Parameter Values

Using O"to" Re/lm and relevant forward differential cross-section data up to the highest available energies we determine the P, f, p, OJ, A2 intercepts and forward residues in nN, NN and KN scattering. We find evidence for low-lying contributions in the nN and NN non-flip amplitudes including the 0" trajectory in the nN case. We also test various phenomenological notions like exchange degeneracy (EXD) , p universality, OJ universality etc. against our parameter values. Comparison is made with other works.

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