Analysis of cross section and astrophysical S-factor at low energies

2013 ◽  
Author(s):  
Azni Abdul Aziz ◽  
Hasan Abu Kassim ◽  
Muhammad F. Zamrun
Keyword(s):  
Cross Section ◽  
S Factor ◽  
Low Energies

scholarly journals The 12C(a,g)16O Cross Section at Low Energies

1991 ◽  
Vol 44 (4) ◽  
pp. 369 ◽  
Author(s):  
FC Barker ◽  
T Kajino
Keyword(s):  
Cross Section ◽  
Ground State ◽  
State Transitions ◽  
Correct Treatment ◽  
R Matrix ◽  
A Value ◽  
S Factor ◽  
Low Energies ◽  
Cascade Transitions ◽  
Matrix Formula

An R-matrix formula for the cross section for radiative capture reactions is developed and applied to fit recently measured 12C(oc,y)160 data, for both ground-state transitions and cascade transitions through the 6�92 and 7 �12 MeV levels. The correct treatment of the channel contributions is significant for the E2 cascade transitions. Consistent fits of the cascade and ground-state data suggest a value of the channel radius larger than those previously used, and consequently a value of the low-energy astrophysical S-factor appreciably larger than that adopted recently.

scholarly journals The Study of the 6Li(p,γ)7Be Reaction at LUNA

2020 ◽  
Vol 1668 (1) ◽  
pp. 012034
Author(s):  
D. Piatti
Keyword(s):  
Cross Section ◽  
Main Sequence ◽  
Theoretical Calculations ◽  
Nuclear Astrophysics ◽  
Recent Measurement ◽  
Main Sequence Stars ◽  
Primordial Nucleosynthesis ◽  
Direct Measurements ◽  
S Factor ◽  
Low Energies

Abstract The 6Li(p,γ)7Be reaction is mainly involved in two astrophysical scenarios: the primordial nucleosynthesis and 6Li consumption in pre-main and main sequence stars. A recent measurement of 6Li(p,γ)7Be reaction S-factor reported a resonance-like structure at Ecm = 195 keV, which has not been confirmed neither by other direct measurements nor by theoretical calculations. A new experiment was performed at the Laboratory for Underground Nuclear Astrophysics (LUNA). The extremely low background environment allowed to measure the 6Li(p,γ)7Be cross section down to low energies with unprecedented sensitivity leading to clarify the existence of the claimed resonance. Details on the experimental setup and the preliminary results of the ongoing analysis are reported in this work.

The Cross Section for Photo-Disintegration of the Deuteron at Low Energies

1950 ◽  
Vol 80 (2) ◽  
pp. 211-222 ◽  
Author(s):  
G. R. Bishop ◽  
C. H. Collie ◽  
H. Halban ◽  
A. Hedgran ◽  
K. Siegbahn ◽  
...  
Keyword(s):  
Cross Section ◽  
Low Energies ◽  
The Cross

scholarly journals S-factor of 14N(α,γ)18F reaction at low-energies

2018 ◽  
Vol 9 ◽  
pp. 1116-1119
Author(s):  
H. Khalili
Keyword(s):  
S Factor ◽  
Low Energies

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 Material dependence of2H(d,p)3H cross section at the very low energies

2017 ◽  
Vol 154 ◽  
pp. 01024
Author(s):  
Ali İhsan Kılıç ◽  
Konrad Czerski ◽  
Fadime Kuştan-Kılıç ◽  
Natalia Targosz-Sleczka ◽  
Daniel Weissbach ◽  
...  
Keyword(s):  
Cross Section ◽  
Low Energies

Electron Energy Dependence of Amorphization in Zr3Fe

1993 ◽  
Vol 316 ◽  
Author(s):  
A.T. Motta ◽  
L.M. Howe ◽  
P.R. Okamoto
Keyword(s):  
Electron Energy ◽  
Cross Section ◽  
Sharp Increase ◽  
Low Dose ◽  
National Laboratory ◽  
Argonne National Laboratory ◽  
High Energies ◽  
Intermediate Energies ◽  
Low Energies ◽  
Order Of Magnitude

ABSTRACTThis paper reports the results from a study conducted to determine the effect of electron energy on the dose-to-amorphization of Zr3Fe at 23-30 K. Zr3Fe samples were irradiated in the HVEM at Argonne National Laboratory, at energies ranging from 200 to 900 keV. Amorphization occurred at electron energies from 900 keV down to 250 keV. Three distinct regions were observed: between 900 and 700 keV amorphization occurred at a constant low dose of ~ 4 × 1021 e cm-2; a higher plateau at 1022 was observed between 600 and 400 keV, and finally there was a sharp increase in the dose-to-amorphization below 400 keV, so that at 250 keV the necessary dose was an order of magnitude higher than that at 900 keV. In the region below 400 keV there was evidence of a dependence of the dose-to-amorphization on the orientation of the sample with respect to the electron beam. The results can be analyzed in terms of a composite displacement cross section dominated at high energies by displacements of Zr and Fe atoms, by displacements of Fe atoms at intermediate energies and of secondary displacements of lattice atoms by recoil impurities at low energies.

Sign in / Sign up

Export Citation Format

Share Document