Effect of the pigmy resonance on the calculations of the neutron capture cross section

1969 ◽  
Vol 47 (24) ◽  
pp. 2849-2857 ◽  
Author(s):  
J. S. Brzosko ◽  
E. Gierlik ◽  
A. Soltan Jr. ◽  
Z. Wilhelmi
Keyword(s):  
Cross Section ◽  
Compound Nucleus ◽  
Cross Sections ◽  
Neutron Capture ◽  
Capture Cross Section ◽  
Gamma Ray ◽  
Giant Resonance ◽  
Model Calculations ◽  
Experimental Values ◽  
Made In

A comparison of the experimental cross sections of the (n, γ) reaction for several nuclei (103Rh, 127I, 181Ta, 197Au) with the compound nucleus model calculations has been made. In the formula used for the probability of gamma-ray emission from the compound nucleus, the presence of the well-known giant resonance was accounted for, as well as the presence of the "pigmy resonance" appearing at the energy Eγ ≈ 6 MeV. The agreement with the experimental values is better in this case than when the "pigmy resonance" is neglected. The same conclusions can be obtained from the calculations of the shape of the spectrum of neutron capture and from the Γγ/D ratio.

THERMAL NEUTRON CAPTURE CROSS-SECTION OF Na23 AND Mn55

1953 ◽  
Vol 31 (3) ◽  
pp. 204-206 ◽  
Author(s):  
Rosalie M. Bartholomew ◽  
R. C. Hawkings ◽  
W. F. Merritt ◽  
L. Yaffe
Keyword(s):  
Thermal Neutron ◽  
Cross Section ◽  
Cross Sections ◽  
Neutron Capture ◽  
Half Life ◽  
Capture Cross Section ◽  
Thermal Neutron Capture ◽  
Capture Cross ◽  
Neutron Capture Cross Section ◽  
Capture Cross Sections

The thermal neutron capture cross sections of Na23 and Mn55 have been determined using the activation method. The values are 0.53 ± 0.03 and 12.7 ± 0.3 barns respectively with respect to σAul97 = 93 barns. These agree well with recent pile oscillator results. The half-life for Mn56 is found to be 2.576 ± 0.002 hr.

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.

Measurement of Neutron Capture Cross Section and Gamma-Ray Spectra of 88Sr in keV Energy Region

2011 ◽  
Vol 59 (2(3)) ◽  
pp. 1844-1847 ◽  
Author(s):  
T. Katabuchi ◽  
N. C. Hai ◽  
M. Igashira ◽  
S. Kamada ◽  
M. Tajika ◽  
...  
Keyword(s):  
Cross Section ◽  
Neutron Capture ◽  
Energy Region ◽  
Capture Cross Section ◽  
Gamma Ray ◽  
Capture Cross ◽  
Neutron Capture Cross Section

scholarly journals Neutron capture cross section and capture gamma-ray spectra of138Ba in the keV-neutron energy region

2015 ◽  
Vol 93 ◽  
pp. 02008
Author(s):  
T. Katabuchi ◽  
S. Yanagida ◽  
K. Terada ◽  
N. Iwamoto ◽  
M. Igashira
Keyword(s):  
Cross Section ◽  
Neutron Energy ◽  
Neutron Capture ◽  
Energy Region ◽  
Capture Cross Section ◽  
Gamma Ray ◽  
Capture Cross ◽  
Neutron Capture Cross Section

scholarly journals Statistical model calculations of the 7Li +11 Β reaction

2019 ◽  
Vol 10 ◽  
pp. 165
Author(s):  
C. Tsabaris ◽  
C. T. Papadopoulos ◽  
R. Vlastou ◽  
A. A. Pakou ◽  
P. A. Assimakopoulos ◽  
...  
Keyword(s):  
Experimental Data ◽  
Statistical Model ◽  
Energy Range ◽  
Cross Section ◽  
Compound Nucleus ◽  
Cross Sections ◽  
Coulomb Barrier ◽  
Reaction Channel ◽  
Model Calculations ◽  
The Individual

The 7Li + 11 Β reaction has been studied in the energy range from a little below to about three times the Coulomb barrier by measuring the cross section of the 7- ray transitions in the residual nuclei produced. Statistical compound nucleus calculations have been performed in order to interpret the experimental data as well as to extract cross sections of the individual exit channels. The statistical compound nucleus theory can reproduce rather well the absolute j - ray and the various reaction channel excitation functions.

REACTOR NEUTRON CAPTURE CROSS SECTION OF 51-DAY Sr89

1957 ◽  
Vol 35 (10) ◽  
pp. 1215-1219 ◽  
Author(s):  
L. P. Roy ◽  
J. C. Roy
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Neutron Capture ◽  
Capture Cross Section ◽  
High Flux ◽  
Capture Cross ◽  
Neutron Capture Cross Section ◽  
Naturally Occurring ◽  
Reactor Spectrum ◽  
Capture Cross Sections

The neutron capture cross section of Sr89 has been measured by an activation method. Naturally occurring strontium was irradiated in different high flux positions in the NRX reactor at Chalk River and the amount of Sr90 formed by successive neutron capture in Sr88 was determined by separating and measuring its daughter Y90. Using values of 36.6 and 0.005 barns for the respective neutron capture cross sections of Co59 and Sr88, the capture cross section of Sr89 for reactor spectrum neutrons was found to be 0.49 ± 0.10 barn.

scholarly journals Cross Section Measurements in the 54Cr(p, ?)55Mn Reaction

1979 ◽  
Vol 32 (4) ◽  
pp. 335 ◽  
Author(s):  
R. J. Wilkinson ◽  
A S. R. Kennett ◽  
A Z. E. Switkowski ◽  
D. G. SargoodA and F. M. MannC
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Reaction Cross Section ◽  
Proton Energy ◽  
Gamma Ray ◽  
Reaction Cross ◽  
Model Calculations ◽  
Global Parameter ◽  
Dramatic Effect ◽  
Bombarding Energy

Cross sections for production of individual y rays in the 54Cr(p, y)55Mn reaction have been measured over the proton energy range 1�0-3�8 MeV. Gamma-ray yields are observed to fall by factors of between 5 and 10 at the crossing of the neutron threshold for a proton bombarding energy of 2�2 MeV. Statistical model calculations with global parameter sets successfully account for the dramatic effect of neutron competition on the (p, y) cross section, and at the same time correctly predict the 54Cr(p,n)54Mn reaction cross section.

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