Determination of (n,2n) Reaction Cross Sections for Some Nuclei with Asymmetry Parameter (original) (raw)
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Nuclear Physics and Atomic Energy, 2018
In the present research, neutron induced reaction cross sections of 69,71 Ga(n, 2n), 69,71 Ga(n, p), 75 As(n, 2n) and 75 As(n, p) were investigated up to 20 MeV. Three theoretical calculation codes (EMPIRE 3.2, TALYS 1.6 and ALICE/ASH) were used for model calculations based on the Weisskopf-Ewing and Hauser-Feshbach theories. The results of theoretical calculations were compared with some empirical formulas developed by different researches, with evaluated nuclear data sets (JENDL-4.0u2 (2012), TENDL-2015, JEFF-3.2 (2014), and ENDF/B-VIII.0 (2018)) and also with the available experimental data found in literature.
Journal of Radioanalytical and Nuclear Chemistry, 1998
The (n,2n) threshold reaction cross-sections, available in the literature are analysed for nuclei with 20≤Z≤92 in the neutron energy range of about 14.5 MeV. An empirical formula based on multiple regression technique is proposed for quick estimation of the (n,2n) reaction cross sections. The results obtained are compared with experimental data and those from other empirical formulae as long as byN-Z systematic. The validity of this formula is discussed.
A Systematic Study for Cross Sections on (d, 2n) Nuclear Reactions Between 11.57 and 18.91 MeV
Journal of Fusion Energy, 2016
The cross sections of deuteron-induced nuclear reactions have a critical importance on future fusion devices. In this study, the Coulomb and asymmetry term effects for the cross sections of (d, 2n) nuclear reactions have been investigated. The reaction cross sections have been calculated by using empirical formulas depended on the asymmetry parameter for incident deuteron energies between 11.57 and 18.91 MeV. The results obtained from the formulas have been discussed and compared with the TENDL-2013 online library data, the code ALICE/ASH calculations (equilibrium Weisskopf Ewing, pre-equilibrium hybrid and geometry dependent hybrid theories) and the experimental values in literature. The present empirical formulas predictions of the reaction cross sections show generally good agreement with the model results and experimental values. Keywords Asymmetry parameter Á (d, 2n) reaction cross section Á Empirical formulas Á ALICE/ASH code Á TENDL-2013 & M.
Annals of Nuclear Energy, 2012
Off-line c-ray spectrometric technique 7 Li(p, n) 7 Be reaction Neutron energies of 8.04 ± 0.3 MeV and 11.9 ± 0.35 MeV Talys 1.2 computer code a b s t r a c t The 232 Th(n, c) 233 Th and 232 Th(n, 2n) 231 Th reaction cross-sections have been determined for the first time at average neutron energies of 8.04 ± 0.30 MeV and 11.90 ± 0.35 MeV using activation and off-line c-ray spectrometric technique. The neutron beam was generated using 7 Li(p, n) reaction. The experimentally determined cross-sections were compared with the evaluated nuclear data libraries of ENDF/B-VII and JENDL 4.0 and are found to be in good agreement. The 232 Th(n, c) 233 Th and 232 Th(n, 2n) 231 Th reaction cross-sections were also calculated theoretically using TALYS 1.2 computer code and compared with the experimental data.
Journal of Radioanalytical and Nuclear Chemistry, 2019
In this article, we are presenting the results of model calculations for (n,p) and (n,2n) reaction cross sections using the standard nuclear reaction codes TALYS-1.8 and EMPIRE-3.2 for 67,70 Zn, 92,96,100 Mo and 208 Pb isotopes in neutron energy range 0-20 MeV. Different nuclear level density models and optical model potential available in the codes have been tested for the estimation of cross sections of desired nuclear reactions. Moreover, in this work, the contribution to the cross section from different reaction mechanisms such as compound nucleus process, pre-equilibrium emission and direct reaction is also discussed in detail. The calculated results are compared with the existing experimental data from the IAEA-EXFOR database.
The Systematics Study of (n, p) Reaction Cross-Sections at 14.7 MeV Neutron Energy
World Journal of Nuclear Science and Technology, 2022
Based on the statistical model and taking into account the Q-value dependence and odd-even effects, we proposed a new empirical formula to reproduce the cross sections of the (n, p) reactions at 14.7 MeV neutron energy and at the target mass number 14 ≤ A ≤ 198 for even A and 29 ≤ A ≤ 205 for odd A. All calculated results from the proposed empirical formula were compared to the experimental data as well as the available semi-empirical formula obtained by other authors. A high level of agreement has been found between the collected experimental data and the most of semiempirical formulae obtained by others.
2014
The effect of the odd-even nature and mass of target nucleus on neutron reaction cross-sections have been investigated for the energy range of 1 – 30 MeV for neutron-induced reactions in the odd – A nuclides: , and using the EXIFON code. This code which uses one global parameter set and is based on the analytical model for statistical multistep direct and multistep compound reactions, was used to calculate cross-sections for the (n, ?), (n, p), and (n, 2n) reactions. Calculations were compared with experimental data (EXFOR) and evaluated data (ENDF) from the IAEA nuclear data bank. Results show that charged particle emissions (( n , ? ) and ( n , p )) are the most dominant reaction channels in the light and intermediate mass nuclei considered. Results also show that the Na ( n , 2n ) reaction cross-section over predicted experimental and evaluated data, while the Na ( n , ? ) reaction agrees with experimental data and was in fair agreement with evaluated data while the Na (n, p) c...
An extensive assessment of the predictive capabilities of different nuclear models in the reproduction of experimental activation and transmutation cross- sections for neutron induced reactions is presented. Experimental EXFOR data have been processed and treated in order to systematically analyze all the available measurements for target nuclei from 27Al to 209Bi with energy of the projectile above 0.1 MeV. Experimental data have been compared with the correspondent simulations performed by means of the TALYS code and the ALICE/ASH code using different models for the description of the nuclear level densities at equilibrium states, these being both phenomenological and microscopic ones. The comparison between measurements and calculations is quantified by means of different statistical deviation factors, which are given as functions of the target nuclei mass number and of different channels. Recommendations are provided to the users on the best combinations of codes and models to o...
Phenomenological approach affecting of (n, p) reaction cross sections via 14.5-MeV neutrons
Indian Journal of Physics, 2018
A new systematic formula is suggested to evaluate the (n, p) reaction cross sections at neutron energy of 14.5 MeV based upon the reaction's Q-value dependence, explicit symmetry breaking, and shell effects. The measured data for the (n, p) reaction cross sections have been gathered from the available literature, and then, it was analyzed for isotopes having 3 B Z B 83. It has been noted that the plot of r (n,p) against Z A 3=2 À Á , N À Z þ 1 ð Þ A 4=3 À Á and N=Z Á A 2=3 À Á is more efficient in determining the (n, p) reaction cross sections, as the reaction Q-value is related to values of r (n,p) too, which has been adequately represented and compared to other terms such as S p , S n , and S a separation energies. The odd-even effects investigated in the cross sections of odd-mass nuclei are higher than those of their neighboring eveneven nuclei close to magic numbers. The estimates of the current formula are compared with the experimental data gathered from the literature, and they are found to be in good agreement.
This booklet contains the notes of lectures given at the workshop entitled “Workshop on Nuclear Reaction Theory and Cross section Data Determination using Computer Codes” held at the National Mathematical Centre (NMC), Abuja, Nigeria, May 19 to 24, 2013. In the first part, the workshop focused on theoretical background of nuclear reaction and covered most and fundamental physics including the mechanisms of the subject matter. The second part of the workshop was devoted to an exhaustive survey on calculational codes based on the theoretical background provided in the first part. Furthermore, relevant experimental data and evaluated data were retrieved from nuclear data libraries and were used to validate calculated data with applications in wide variety of fields. This collection should present a useful reference for researchers interested in this topic. Specifically, graduate students of nuclear physics, nuclear engineering and computational physics/ engineering will find the collec...