Average recoil ranges of 64Cu and 196Au produced by protons of 20–85 MeV energy in 65Cu and 197Au

1968 ◽  
Vol 46 (20) ◽  
pp. 3157-3170
Author(s):  
M. K. Dewanjee ◽  
G. B. Saha ◽  
L. Yaffe
Keyword(s):  
Statistical Theory ◽  
Inelastic Scattering ◽  
Reasonable Agreement ◽  
Interaction Mechanism ◽  
Direct Interaction ◽  
Thick Target ◽  
Model Calculations ◽  
Projected Range ◽  
Low Energies ◽  
The Average Range

Thick-target recoil experiments were performed to study (p,pn) reactions induced in 65Cu and 197Au in the energy range of 20–85 MeV and the average ranges projected in the forward, backward, and perpendicular directions were determined. Recoil parameters have been calculated to show approximately the amount of energy transfer and their energy dependence. The average range results have been compared with statistical theory, cascade–evaporation (85 MeV only), and inelastic scattering model calculations. The statistical calculations show reasonable agreement up to 30–40 MeV. However, the calculated projected range values, based on the cascade–evaporation and the inelastic scattering models, are consistently lower than the measured values. The analyses of the projected range values support the prevalent view that at low energies (~ 30–35 MeV), the compound nucleus mechanism is predominant and at higher energies, the direct interaction mechanism makes a major contribution.

Angular distributions of recoil products from some reactions induced in 65Cu and 197Au by protons of energy 30–85 MeV

1968 ◽  
Vol 46 (22) ◽  
pp. 3551-3563 ◽  
Author(s):  
M. K. Dewanjee ◽  
G. B. Saha ◽  
L. Yaffe
Keyword(s):  
Angular Distribution ◽  
Inelastic Scattering ◽  
Center Of Mass ◽  
Interaction Mechanism ◽  
Direct Interaction ◽  
Low Energy ◽  
Angular Distributions ◽  
Approximate Symmetry ◽  
Mass System ◽  
Model Calculations

Angular distributions of products formed in the reactions 65Cu(p,pn)64Cu, 197Au(p,pn)I96Au, and 197Au(p,p3n)194Au in the range of proton energy 30–85 MeV were studied. The angular distribution results of 64Cu and 196Au show forward peaking at low energy and sidewise peaking at higher energies. Approximate symmetry about 90° was observed for the angular distribution of 194Au in the center-of-mass system. The experimental results have been compared with (a) Monte Carlo evaporation calculations, (b) cascade–evaporation calculations at 85 MeV for 64Cu, and (c) inelastic scattering plus evaporation calculations.Good agreement was obtained with statistical theory calculations at low energy and inelastic scattering model calculations at higher energies. The comparisons indicate that the reactions proceed by the compound nucleus mechanism at lower energies and the direct interaction mechanism predominates at higher energies.

82. A direct interaction model for inelastic scattering

Physica ◽  
1956 ◽  
Vol 22 (6-12) ◽  
pp. 1163-1164
Author(s):  
N.C. Francis ◽  
P.F. Zweifel
Keyword(s):  
Inelastic Scattering ◽  
Interaction Model ◽  
Direct Interaction

scholarly journals The 7Be(p, ?)8B Cross Section at Low Energies

1980 ◽  
Vol 33 (2) ◽  
pp. 177 ◽  
Author(s):  
FC Barker
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Solar Neutrinos ◽  
Model Calculations ◽  
Spectroscopic Factors ◽  
Low Energies ◽  
Standard Values ◽  
Experimental Values ◽  
Parameter Values ◽  
Potential Parameters

The nonresonant part of the 7Be(p, )I)8B cross section at low energies is recalculated by means of a direct-capture potential model, using parameter values determined by fitting 7Li(n, n)7Li and 7Li(n, )I)8Li data. Standard values of the potential parameters and spectroscopic factors give values of the 7Li(n,)I) cross section that are too large. Modified values that fit the thermal-neutron capture cross section predict 7Be(p,)I) cross sections that are much less than the experimental values. Also, shell model calculations predict resonant 7Be(p,)I) cross sections that are smaller than the experimental values. It is suggested that the accepted experimental values of the 7Be(p, )I) cross section may be too large, perhaps due partly to an overlarge accepted value for the 7Li(d, p)8Li cross section, which has been used for normalization purposes. A decrease in the 7Be(p,)I) cross section would reduce the calculated detection rate of solar neutrinos and lessen the discrepancy with the measured value.

scholarly journals Experimental measurement of the 12C+16O fusion cross sections at astrophysical energies

2018 ◽  
Vol 178 ◽  
pp. 04008
Author(s):  
X. Fang ◽  
W. P. Tan ◽  
M. Beard ◽  
R. J. deBoer ◽  
G. Gilardy ◽  
...  
Keyword(s):  
Cross Sections ◽  
Center Of Mass ◽  
Model Calculations ◽  
Center Of Mass Energy ◽  
Pure Graphite ◽  
S Factor ◽  
Hpge Detectors ◽  
Low Energies ◽  
The University

The total cross sections of the 12C+16O fusion have been experimentally determined at low energies to investigate the role of this reaction during late stellar evolution burning phases. A high-intensity oxygen beam was produced by the 5MV pelletron accelerator at the University of Notre Dame impinging on a thick ultra-pure graphite target. Protons and γ-rays were measured simultaneously in the center-of-mass energy range from 3.64 to 5.01 MeV, using strip silicon and HPGe detectors. Statistical model calculations were employed to interpret the experimental results. A new broad resonance-like structure is observed for the 12C+16O reaction, and a decreasing trend of its S-factor towards low energies is found.

Elastic and inelastic scattering of 40 MeV polarized protons from 90Zr and 92Zr

1979 ◽  
Vol 57 (4) ◽  
pp. 540-549 ◽  
Author(s):  
R. de Swiniarski ◽  
Dinh-Lien Pham ◽  
G. Bagieu ◽  
H. V. Geramb
Keyword(s):  
Inelastic Scattering ◽  
Cross Sections ◽  
Imaginary Component ◽  
Spin Orbit ◽  
Model Calculations ◽  
Analyzing Powers ◽  
Elastic And Inelastic Scattering ◽  
Polarized Protons ◽  
The Cross ◽  
Good Agreement

Analyzing powers and cross sections have been measured for elastic and inelastic scattering of 40 MeV polarized protons from 90Zr and 92Zr. The analysis has been carried out in the DWBA within the framework of the macroscopic and microscopic models. Furthermore, the coupled-channels calculations using the vibrational model and the full Thomas form for the spin–orbit potential give a very good description for both the cross sections and the analyzing powers of the iow-lying2+, 3−, 5−, and 4+ states in 92Zr and the 2+ and 3− in 90Zr. The cross section and analyzing power for the first 2+ state in these nuclei were compared with previous results at 30 and 20.3 MeV, and from this comparison a certain energy dependence of the relative strength of the spin–orbit deformation to the central deformation could be observed. Microscopic model calculations with tensor and spin–orbit components included in the projectile–target real interaction and with an exact treatment of knock-on' exchange have been performed for the 2+ states in these nuclei. An attempt has also been made in order to include the imaginary component in the N–N interaction. For these calculations, rather good agreement was obtained especially for the 2+ state in 92Zr but poor agreement for 90Zr. Finally, valence plus core polarization calculations have also been done and showed a very good agreement between theory and experiment for those 2+ transitions.

THE SPECTRUM OF NEUTRONS FROM THE IRRADIATION OF URANIUM BY 14-MEV NEUTRONS

1961 ◽  
Vol 39 (7) ◽  
pp. 957-966 ◽  
Author(s):  
R. L. Clarke
Keyword(s):  
Inelastic Scattering ◽  
Cross Section ◽  
Neutron Beam ◽  
Strong Evidence ◽  
Direct Interaction ◽  
Natural Uranium ◽  
Incident Neutron ◽  
Absolute Yield ◽  
Time Of Flight Method ◽  
Incident Neutron Beam

The spectrum and absolute yield of neutrons resulting from 14-Mev neutrons incident on natural uranium was observed at 90°± 16 to the incident neutron beam by a time-of-flight method. Further observations of the spectrum from 9 to 13.5 Mev were made for scattering angles at 30° and 60°. In addition to the expected neutrons resulting from evaporation and fission, strong evidence is seen for direct interaction inelastic scattering. The (n,n′) cross section is estimated to be 150 ± 70 millibarns.

Absorption Potential for Dynamic Electron Diffraction - A Revisit

1998 ◽  
Vol 4 (S2) ◽  
pp. 340-341
Author(s):  
Z.L. Wang ◽  
Chen Zhang
Keyword(s):  
Electron Diffraction ◽  
Inelastic Scattering ◽  
Structural Information ◽  
Dynamic Calculation ◽  
Model Calculations ◽  
Reflected Waves ◽  
Transmission Electron ◽  
Absorption Potential ◽  
Non Local ◽  
Almost All

Quantitative analysis of structural information provided by transmission electron diffraction and imaging strongly relies on computer simulations. An important quantity in dynamic calculation is the “absorption” potential. The absorption here actually means that the electron is not absorbed by the specimen rather it is scattered out of the elastic state (or Bragg peaks) due to energy-loss and momentum transfer, resulting in a decrease in the intensity of the elastic wave. This is the effect of inelastic scattering (or diffuse scattering) on the Bragg reflected waves [1]. Almost all of the model calculations for the absorption potential have been based on the approximation o riginally introduced by Y o sh ioka, in which the Green's function is approximated by its form in free-space. Thus, the absorption potential is simplified into a non-local function that depends only on the nature of the inelastic scattering.

A STUDY OF THE Be9(He3, n)C11 REACTION

1963 ◽  
Vol 41 (7) ◽  
pp. 1036-1046 ◽  
Author(s):  
L. van der Zwan ◽  
A. T. Stewart ◽  
J. Y. Park ◽  
E. Merzbacher
Keyword(s):  
Compound Nucleus ◽  
Cross Sections ◽  
Interaction Mechanism ◽  
Direct Interaction ◽  
Particle Energy ◽  
Energy Spectra ◽  
Angular Distributions ◽  
Proton Recoil ◽  
The Cross ◽  
Photographic Emulsions

The energy spectra and angular distributions of the emergent neutrons from the Be9(He3, n)C11 reaction have been obtained for an incident He3-particle energy of 2 Mev with the technique of observing proton recoil in photographic emulsions. The cross sections were normalized to Be9(He3, p)B11 data observed simultaneously at 90° to the beam. The lack of similarity in the (He3, n) and (He3, p) mirror reactions to some residual states suggests a direct interaction mechanism rather than compound nucleus. An attempt to analyze some of the data in terms of double particle stripping has been made.

Direct interaction theory of inelastic scattering. Part I

1957 ◽  
Vol 2 (5) ◽  
pp. 471-498 ◽  
Author(s):  
Carl A Levinson ◽  
Manoj K Banerjee
Keyword(s):  
Inelastic Scattering ◽  
Direct Interaction ◽  
Interaction Theory
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