scholarly journals Modeling radiative proton-capture reactions in mid-heavy nuclei

2019 ◽  
Vol 23 ◽  
pp. 146
Author(s):  
E. Batziou ◽  
V. Koutsilianou ◽  
L. Stavropoulos ◽  
A. Psaltis ◽  
T. J. Mertzimekis
Keyword(s):  
Experimental Data ◽  
Cross Sections ◽  
Systematic Study ◽  
Low Energy ◽  
Heavy Nuclei ◽  
Proton Capture ◽  
Experimental Conditions ◽  
Energy Regime ◽  
Theoretical Predictions ◽  
Near Future

A systematic study of (p,γ) reactions was carried out using the reaction codes EMPIRΕ, TALYS and NON-SMOKER (web). The calculated (p,γ) cross sections of seed nuclei 89Y, 107,109Ag, 106,108,110Pd, 112Cd, 121,123Sb, 127I, and 133Cs can be used in a three-fold way: (a) perform an intercomparison of the models in a low-energy regime (b) compare existing experimental data to the theoretical predictions and (c) predict cross sections of reactions planned to be studied experimentally in the near future by our group. The results of the study are presented in a concise way focusing on the experimental conditions.

scholarly journals Quest for precision in hadronic cross sections at low energy: Monte Carlo tools vs. experimental data

2010 ◽  
Vol 66 (3-4) ◽  
pp. 585-686 ◽  
Author(s):  
S. Actis ◽  
◽  
A. Arbuzov ◽  
G. Balossini ◽  
P. Beltrame ◽  
...  
Keyword(s):  
Experimental Data ◽  
Monte Carlo ◽  
Cross Sections ◽  
Low Energy

Low-energy positron–hydrogen molecule scattering

1982 ◽  
Vol 60 (4) ◽  
pp. 597-600 ◽  
Author(s):  
Sukanya Sur ◽  
A. S. Ghosh
Keyword(s):  
Cross Sections ◽  
Effective Potential ◽  
Qualitative Agreement ◽  
Hydrogen Molecule ◽  
Low Energy ◽  
Total Cross Sections ◽  
Model Potentials ◽  
Theoretical Predictions ◽  
Molecule Scattering

The method of Hara using two centre formalism has been employed to investigate positron–hydrogen molecule scattering at low incident energies. Two model potentials have been used to see the importance of the choice of effective potential. It has been found that the total cross sections are sensitive to the details of the effective potential. The present results are in qualitative agreement with measured values and other existing theoretical predictions.

scholarly journals Anomalous enhancements of low-energy fusion rates in plasmas: the role of ion momentum distributions and inhomogeneous screening

Open Physics ◽  
2009 ◽  
Vol 7 (3) ◽  
Author(s):  
Massimo Coraddu ◽  
Marcello Lissia ◽  
Piero Quarati
Keyword(s):  
Cross Sections ◽  
Thermal Effects ◽  
Quantum Effect ◽  
Reaction Rates ◽  
Low Energy ◽  
Electron Screening ◽  
Quantum Uncertainty ◽  
Spatial Fluctuations ◽  
Theoretical Predictions

AbstractNon-resonant fusion cross-sections significantly higher than corresponding theoretical predictions are observed in low-energy experiments with deuterated matrix target. Models based on thermal effects, electron screening, or quantum-effect dispersion relations have been proposed to explain these anomalous results: none of them appears to satisfactory reproduce the experiments. Velocity distributions are fundamental for the reaction rates and deviations from the Maxwellian limit could play a central role in explaining the enhancement. We examine two effects: an increase of the tail of the target Deuteron momentum distribution due to the Galitskii-Yakimets quantum uncertainty effect, which broadens the energy-momentum relation; and spatial fluctuations of the Debye-Hückel radius leading to an effective increase of electron screening. Either effect leads to larger reaction rates especially large at energies below a few keV, reducing the discrepancy between observations and theoretical expectations.

Structure effects in low-energy electronic stopping

1969 ◽  
Vol 311 (1504) ◽  
pp. 47-51 ◽  
Keyword(s):  
Amorphous Carbon ◽  
Cross Sections ◽  
Wave Functions ◽  
Low Energy ◽  
Thomas Fermi ◽  
Hartree Fock ◽  
Theoretical Predictions

Recent experiments have shown electronic stopping cross-sections to have an oscillatory dependence on ionic atomic numbers with minima in the region of Li, Na and Cu. The amplitudes of the oscillations are enhanced when the ions are channelled. To explain these effects we have modified the Firsov theory of electronic stopping by replacing the Thomas-Fermi atom with simple Hartree-Fock wave functions, thus allowing for the different ionic sizes. Theoretical predictions are made for the stopping cross-sections of ions in amorphous carbon and of channelled ions in silicon.

scholarly journals Antiproton-nucleus annihilation cross section at low energy

2018 ◽  
Vol 182 ◽  
pp. 03013
Author(s):  
H. Aghai–Khozani ◽  
A. Bianconi ◽  
M. Corradini ◽  
R. Hayano ◽  
M. Hori ◽  
...  
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Medical Physics ◽  
Low Energy ◽  
Annihilation Cross Section ◽  
Experimental Result ◽  
Heavy Nuclei ◽  
Fundamental Physics ◽  
Low Energies ◽  
Few Data

The antinucleon-nuclei annihilation cross sections at low energies were systematically measured at CERN in the 80’s and 90’s with the LEAR facility and later with the Antiproton Decelerator. Unfortunately only few data exist for very low energy antiprotons (p<500 MeV/c) on medium and heavy nuclei. A deeper knowledge is required by fundamental physics and can have consequence also in cosmology and medical physics. In order to fill the gap, the ASACUSA Collaboration has very recently measured the annihilation cross section of 100 MeV/c antiprotons on carbon. In the present work the experimental result is presented together with a comparison both with the antineutron data on the same target at the same energies and with the other existing antiproton data at higher energies.

Reaction mechanism of the 16O + d reactions

1970 ◽  
Vol 48 (19) ◽  
pp. 2235-2253 ◽  
Author(s):  
N. E. Davison ◽  
W. K. Dawson ◽  
G. Roy ◽  
W. J. McDonald
Keyword(s):  
Experimental Data ◽  
Compound Nucleus ◽  
Cross Sections ◽  
Direct Interaction ◽  
Scattering Data ◽  
Orbit Potential ◽  
Spectroscopic Factors ◽  
Theoretical Predictions ◽  
Using Data ◽  
Good Agreement

The reactions 16O(d,d)16O, 16O(d,p)17O, and 16O(d,n)17F have been studied in the deuteron energy range 4.00–6.00 MeV in order to determine to what extent current theories can satisfactorily describe these reactions. It was found that the theoretical curves from both the optical and DWBA models fit the experimental data significantly better when the deuteron optical-model potentials had been obtained using a spin–orbit potential in the analysis of the elastic scattering data. Spectroscopic factors obtained for the ground and first-excited states of 17O and 17F using the DWBA theory are in satisfactory agreement with theoretical predictions and with values obtained by previous workers. Small, but nonzero, spectroscopic factors have been obtained for the states at 3.058 and 3.846 MeV excitation in 17O using data measured in this work and in previous experiments. The sum of the calculated direct interaction and compound-nucleus cross sections is in good agreement with experimental data for all states studied, whether they were populated primarily by direct or compound-nucleus reactions. The calculated compound-nucleus lifetimes are also in agreement with values obtained from an analysis of the fluctuations in the yield curves.

scholarly journals Excitation and ionisation cross-sections in condensed-phase biomaterials by electrons down to very low energy: application to liquid water and genetic building blocks

2021 ◽  
Vol 23 (9) ◽  
pp. 5079-5095
Author(s):  
Pablo de Vera ◽  
Isabel Abril ◽  
Rafael Garcia-Molina
Keyword(s):  
Experimental Data ◽  
Cross Sections ◽  
Condensed Phase ◽  
Electronic Excitation ◽  
Building Blocks ◽  
Low Energy ◽  
Wide Energy Range ◽  
Wide Energy ◽  
Energy Application ◽  
Good Agreement

A model is presented for computing electron-impact electronic excitation and ionisation cross-sections for arbitrary condensed-phase biomaterials in a wide energy range, showing a general good agreement with the available experimental data.

scholarly journals Cross sections of proton capture reactions of Sr isotopes

2019 ◽  
Vol 11 ◽  
Author(s):  
S. Galanopoulos ◽  
P. Demetriou ◽  
M. Kokkoris ◽  
G. Kriembardis ◽  
S. Harissopulos ◽  
...  
Keyword(s):  
Cross Sections ◽  
Relative Efficiency ◽  
Background Suppression ◽  
Proton Capture ◽  
Total Cross Sections ◽  
Model Code ◽  
Hpge Detectors ◽  
Theoretical Predictions ◽  
Compton Background ◽  
Good Agreement

Cross section measurements of the proton capture reactions of the 86Sr, 87Sr and 88Sr isotopes were carried out at energies Ep=1.4-5 MeV. At Ep <3.5 MeV an array of 4 HPGe detectors with 100% relative efficiency shielded with BGO scintillators for Compton background suppression was used, whereas at Ep >3.5 MeV, the measurements were performed by means of one HPGe detector of 80% relative efficiency. For the 87Sr(p,7)88Y and 88Sr(p,7)89Y reactions total cross sections ranging from 0.5 μο-5 mb were found. The data analysis of the 86Sr(p,7)87Y reaction is in progress. Cross sections have also been calculated by means of the statistical model code MOST. A very good agreement between the experimental data and the theoretical predictions has been found.

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