scholarly journals New parametrization for the 3He(d, p) 4He fusion reaction rate and refinement of the Lawson criterion for d-3He thermonuclear reactors

2021 ◽  
Vol 2103 (1) ◽  
pp. 012197
Author(s):  
I B Alper ◽  
A I Godes ◽  
V L Shablov
Keyword(s):  
Experimental Data ◽  
Energy Range ◽  
Cross Section ◽  
Reaction Rate ◽  
Nuclear Reactions ◽  
Fusion Reaction ◽  
Theoretical Method ◽  
Reaction Rates ◽  
Lawson Criterion ◽  
Astrophysical Factor

Abstract We present a new parametrization of the d + 3He → p + 4He fusion reaction astrophysical factor based on the effective range approximation, which is an effective theoretical method for describing near-threshold, including resonance, nuclear reactions. In the framework of this approximation we describe experimental data on the energy dependence of the cross section and the astrophysical factor within the experimental uncertainties in the energy range of 0-800 keV. On this basis we calculate the temperature dependence of the Maxwellian-averaged reaction rate in the range of 0-400 keV. In conclusion, we discuss the effect of the calculated reaction rates on the Lawson criterion for thermonuclear reactors based on d-3He fuel.

Fusion and Breakup Reactions of 17S + 208Pb and 15C + 232ThHalo Nuclei Systems

2015 ◽  
Vol 11 (2) ◽  
pp. 2972-2978
Author(s):  
Fouad A. Majeed ◽  
Yousif A. Abdul-Hussien
Keyword(s):  
Experimental Data ◽  
Cross Section ◽  
Fusion Reaction ◽  
Fusion Cross Section ◽  
Reaction Cross ◽  
Recent Experimental Data ◽  
Barrier Distribution ◽  
Coupled Channel ◽  
Total Fusion ◽  
Full Quantum

In this study the calculations of the total fusion reaction cross section have been performed for fusion reaction systems 17F + 208Pb and 15C + 232Th which involving halo nuclei by using a semiclassical approach.The semiclassical treatment is comprising the WKB approximation to describe the relative motion between target and projectile nuclei, and Continuum Discretized Coupled Channel (CDCC) method to describe the intrinsic motion for both target and projectile nuclei. For the same of comparsion a full quantum mechanical clacualtions have been preforemd using the (CCFULL) code. Our theorticalrestuls are compared with the full quantum mechaincialcalcuations and with the recent experimental data for the total fusion reaction  checking the stability of the distancesThe coupled channel calculations of the total fusion cross section σfus, and the fusion barrier distribution Dfus. The comparsion with experiment proves that the semiclassiacl approach adopted in the present work reproduce the experimental data better that the full quantal mechanical calcautions. 

Evaluation of Optical Model Potential Using Neutron Induced Cross Section Reaction for Spherical Uranium-238 Isotope up to 20MeV

2015 ◽  
Vol 59 ◽  
pp. 26-34
Author(s):  
Iman Tarik Al-Alawy ◽  
Ronak Ikram Ali
Keyword(s):  
Experimental Data ◽  
Energy Range ◽  
Cross Section ◽  
Cross Sections ◽  
Optical Model ◽  
Threshold Energy ◽  
Model Potential ◽  
Model Parameters ◽  
Incident Neutron ◽  
Optical Model Potential

The evaluation are based on mainly on the calculations of the nuclear optical model potential and relevant parameters are collected and selected from References Input Parameter Library (RIPL) which is being developed under the international project coordinated by the International Atomic Energy Agency (IAEA). The analyzing of a complete energy range has done starting from threshold energy for each reaction. The cross sections are reproduced in fine steps of incident neutron energy with 0.01MeV intervals with their corresponding errors. The recommended cross sections for available experimental data taken from EXFOR library have been calculated for all the considered neutron induced reactions for U-238 isotopes. The calculated results are analyzed and compared with the experimental data. The optimized optical potential model parameters give a very good agreement with the experimental data over the energy range 0.001-20MeV for neutron induced cross section reactions (n,f), (n,tot), (n,el), (n,inl), (n,2n), (n,3n), and (n,γ) for spherical U-238 target elements.

Calculation of fusion rates at extremely low energies in laser plasmas

2010 ◽  
Vol 6 (S274) ◽  
pp. 44-47 ◽  
Author(s):  
D. Mascali ◽  
N. Gambino ◽  
S. Tudisco ◽  
A. Anzalone ◽  
A. Bonanno ◽  
...  
Keyword(s):  
Nuclear Reactions ◽  
Fusion Reaction ◽  
Reaction Rates ◽  
Debye Screening ◽  
Fusion Reactions ◽  
Plasma Dynamics ◽  
Laser Plasmas ◽  
Low Energies ◽  
Screening Factor ◽  
The One

AbstractAt temperatures and densities that are typical of plasmas produced by lasers pulses interacting with solid targets, at power intensities I > 1012W/cm2, the classical Debye screening factor in nuclear reactions becomes comparable with the one of the solar core. Preliminary calculations about the total number of fusion reactions have been performed following an hydrodynamical approach for the description of the plasma dynamics. This approach is propaedeutic for future measurements of D-D fusion reaction rates.

scholarly journals Screening effects on resonant thermonuclear reaction rates

2019 ◽  
Vol 11 ◽  
Author(s):  
T. Liolios ◽  
K. Langanke ◽  
W. Wiescher
Keyword(s):  
Reaction Rate ◽  
Nuclear Reactions ◽  
Reaction Network ◽  
Reaction Rates ◽  
Partial Width ◽  
Entrance Channel ◽  
Correction Factors ◽  
Thermonuclear Reaction ◽  
Hydrogen Burning ◽  
Stellar Reaction Rate

The reaction rate of several astrophysically important nuclear reactions is dominated by the contribution of narrow resonances at the astrophysically most effective energies. In the stellar plasma the partial width of the resonances in the entrance channel is modified due to screening corrections. This effect, so far ignored in stellar reaction network calculations, reduces the conventional Salpeterscreening enhancement of the reaction rate. We derive analytical screening correction factors for the contributions of narrow resonances to the stellar reaction rate and discuss the effects for UC (a, j)lsO, 150(a,7)19 Ne and other reactions of relevance to explosive hydrogen burning

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.

scholarly journals A systematic study of proton capture reactions in the Se-Sn region relevant to p-process nucleosynthesis

2019 ◽  
Vol 11 ◽  
Author(s):  
S. Harissopulos ◽  
P. Demetriou ◽  
S. Galanopoulos ◽  
G. Kriembardis ◽  
M. Kokkoris ◽  
...  
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Nuclear Physics ◽  
Nuclear Reactions ◽  
Reaction Network ◽  
Reaction Rates ◽  
Compton Suppression ◽  
Experimental Information ◽  
Systematic Investigation ◽  
Model Calculations

The synthesis of the so-called ρ nuclei, i.e. a certain class of proton rich nuclei that are heavier than iron, requires a special mechanism known as ρ process. This process consists of various nucleosynthetic scenaria. In some of them proton and alpha-capture reactions are strongly involved, p-process nucleosynthesis is assumed to occur in the Oxygen/Neon rich layers of type II supernovae during their explosion, ρ nuclei are typically 10-100 times less abundant than the corresponding more neutron-rich isotopes. The prediction of their abundances is one of the major puzzles of all models of p-process nucleosynthesis. Until now all these models are capable of reproducing these abundances within a factor of 3. However, they all fail in the case of the light ρ nuclei with A<100. The observed discrepancies could be attributed to uncertainties in the pure "astrophysical" part of the p-process modelling. However, they could also be the result of uncertainties in the nuclear physics data entering the corresponding abundance calculations. In order to perform these calculations the cross sections of typically 10000 nuclear reactions of an extended reaction network involving almost 1000 nuclei from A=12 to 210 are used as input data. Such a huge amount of experimental cross section data are not available. Hence, all extended network calculations rely almost completely on cross sections predicted by the Hauser-Feshbach (HF) theory. It is therefore of paramount importance, on top of any astrophysical model improvements, to test also the reliability of the HF calculations, i.e. to investigate the uncertainties associated with the evaluation of the nuclear properties, like nuclear level densities and nucleon-nucleus potentials, entering the calculations. Until now, this check has been hindered significantly by the fact that in the Se-Sn region there has been scarce experimental information on cross sections at astrophysically relevant energies. In the present work, a systematic investigation of (p,7) cross sections of nuclei from Se to Sb is presented for the first time. The in-beam cross section measurements reported were carried out at energies relevant to p-process nucleosynthesis, i.e. from 1.4 to 5 MeV. The experiments were performed by using either an array of 4 HPGe detectors of 100% relative efficiency shielded with BGO crustals for Compton suppression, or a 4π Nal summing detector. The resulting cross sections, astrophysical S-factors and reaction rates of more than 10 nuclear reactions are compared with the predictions of various statistical model calculations.

scholarly journals Optical Model Potential Using CINDA Library for Neutron Induced Cross Section Reactions for Spherical Uranium-235,238 Isotopes

2015 ◽  
Vol 60 ◽  
pp. 66-73
Author(s):  
Iman Tarik Al-Alawy ◽  
Ronak Ikram Ali
Keyword(s):  
Experimental Data ◽  
Energy Range ◽  
Cross Section ◽  
Cross Sections ◽  
Optical Model ◽  
Threshold Energy ◽  
Model Potential ◽  
Model Parameters ◽  
Incident Neutron ◽  
Optical Model Potential

The calculation are based mainly on the nuclear optical model potential and relevant parameters are collected and selected from References Input Parameter Library (RIPL) which is being developed under the international project coordinated by the International Atomic Energy Agency (IAEA). The analyzing of a complete energy range has done starting from threshold energy for each reaction. The cross sections are reproduced in fine steps of incident neutron energy with 0.01MeV intervals with their corresponding errors. The recommended cross sections for available experimental data taken from CINDA library have been calculated for all the considered neutron induced reactions for spherical U-235 and U-238 isotopes. The calculated results are analyzed and compared with the experimental data. The optimized optical potential model parameters give a very good agreement with the experimental data over the energy range 0.001-20MeV for neutron induced cross section reactions (n,f), (n,tot), (n,el), (n,inl), (n,2n), (n,3n), and (n,γ) for spherical U-235 and U-238 target elements.

scholarly journals An increase in the 12C+12C fusion rate from resonances at astrophysical energies

2019 ◽  
Vol 52 (382) ◽  
pp. MISC6-MISC8
Author(s):  
Aurora Tumino
Keyword(s):  
Neutron Stars ◽  
Cross Sections ◽  
Coulomb Barrier ◽  
Reaction Rate ◽  
Nuclear Reactions ◽  
Massive Stars ◽  
Reaction Rates ◽  
Fusion Reactions ◽  
Trojan Horse Method ◽  
Carbon Burning

Carbon burning powers pivotal scenarios that influence the fate of stars, such as the late evolutionary stages of massive stars (exceeding eight solar masses), superbursts from accreting neutron stars and progenitors of Type Ia supernovae. It proceeds through the 12C+12C fusion reactions that produce an \( \alpha \) particle and neon-20 or a proton and sodium-23 —that is, 12C(12C, \( \alpha \) )20Ne and 12C(12C, \( p \))23Na— at temperatures greater than \( 0.4 \cdot 10^9 \) K, corresponding to astrophysical energies exceeding a megaelectronvolt (MeV), at which such nuclear reactions are more likely to occur in stars. The cross-sections for those carbon fusion reactions (probabilities that are required to calculate the rate of the reactions) have never been measured below 2 MeV because of exponential suppression arising from the Coulomb barrier (the Coulomb barrier is around 6 MeV). The reference rate at temperatures below \( 1.2\cdot 10^9 \) K relies on extrapolations that ignore the effects of possible low-lying resonances. In Tumino et al. (2018), we report the measurement of the 12C(12C, \( \alpha_{0,1} \)) 20Ne and 12C(12C, \( p_{0,1} \)) 23Na reaction rates (where the subscripts 0 and 1 stand for the ground and first excited states of 20Ne and 23Na, respectively) at centre-of-mass energies from 2.7 to 0.8 MeV using the Trojan Horse method and the deuteron in 14N. This is an indirect technique aiming at measuring low-energy nuclear reactions unhindered by the Coulomb barrier and free of electron screening. The deduced cross-sections exhibit several resonances that are responsible for a very large increase of the reaction rate at the relevant temperatures. In particular, around \( 5\cdot 10^8 \) K, the reaction rate is more than 25 times larger than the reference value. This finding may have significant implications such as lowering the temperatures and densities required for the ignition of carbon burning in massive stars and decreasing the superburst ignition depth in accreting neutron stars in the direction to reconcile observations with theoretical models.

Production of 67Cu by enriched 70Zn targets: first measurements of formation cross sections of 67Cu, 64Cu, 67Ga, 66Ga, 69mZn and 65Zn in interactions of 70Zn with protons above 45 MeV

2020 ◽  
Vol 108 (8) ◽  
pp. 593-602 ◽  
Author(s):  
Gaia Pupillo ◽  
Liliana Mou ◽  
Petra Martini ◽  
Micòl Pasquali ◽  
Alessandra Boschi ◽  
...  
Keyword(s):  
Experimental Data ◽  
Cancer Therapy ◽  
Energy Range ◽  
Cross Section ◽  
Cross Sections ◽  
High Intensity ◽  
Chemical Processing ◽  
Γ Spectrometry ◽  
First Time ◽  
Theoretical Results

AbstractDespite its insufficient availability, Copper-67 is currently attracting much attention for its enormous potential for cancer therapy as theranostic radionuclide. This work aims to accurately measure the unexplored cross section 70Zn(p,x)67Cu in the energy range 45–70 MeV and to evaluate its potential advantages in the case of high-intensity proton beams provided by compact cyclotrons. Thin target foils of enriched 70Zn were manufactured by lamination at the INFN-LNL and irradiated at the ARRONAX facility using the stacked-foils method. A radiochemical procedure for the separation of Cu, Ga and Zn contaminants and the isolation of 67Cu from the irradiated material was developed. The efficiency of the chemical processing was determined for each foil by monitoring the activity of selected tracer radionuclides (61Cu, 66Ga and 69mZn) through γ-spectrometry. Experimental data of the 70Zn(p,x)67Cu, 64Cu, 67Ga, 66Ga, 69mZn, 65Zn cross sections were measured for the first time in the energy range 45–70 MeV and compared with the theoretical results obtained by using the TALYS code. The 67Cu production yield by using enriched 70Zn thick targets was compared with the results obtained by using 68Zn targets in the same irradiation conditions.

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