Cross-section calculations of (n,2n) and (n,p) reactions for 69,71Ga and 75As target nuclei up to 20 MeV (original) (raw)

On the Accuracy of Different Theoretical Models in the Prediction of Neutron Induced Reaction Cross-Sections at Intermediate Energies

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...

An empirical formula for (n, 2n) reaction cross sections in the neutron energy range of about 14.5 MeV

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.

Cross Section Calculations of (n,2n) and (n,p) Nuclear Reactions on Germanium Isotopes at 14–15 MeV

Journal of Fusion Energy, 2016

Neutron incident reaction cross sections of Germanium isotopes (70,72,74,76 Ge) were investigated for the (n,2n) and (n,p) reactions around 14-15 MeV. Cross section calculations have been presented for 70 Ge(n,2n) 69 Ge, 72 Ge(n,2n) 71 Ge, 74 Ge(n,2n) 73 Ge, 76 Ge(n, 2n) 75 Ge, 70 Ge(n,p) 70 Ga, 72 Ge(n,p) 72 Ga, 74 Ge(n,p) 74 Ga, and 76 Ge(n,p) 76 Ga reactions. Theoretical calculations were performed with four different computer codes: ALICE/ ASH for the Geometry Dependent Hybrid model, TALYS 1.6 for two component Exciton model, EMPIRE 3.2 Malta for Exciton model and PCROSS for Full Exciton model with the incident neutron energy up to 20 MeV. The (n,2n) and (n,p) reaction cross section calculations were compared with empirical formulas derived by several researchers and compared with the experimental data obtained from EXFOR database as well as with evaluated Nuclear data files (ENDF/B-VII.1: USA 2014). Results show good agreement between the theoretical calculations having a major importance in nuclear data evaluation calculations and the experimental data from literature.

Cross section calculation of (n,p) and (n,2n) nuclear reactions on Zn, Mo and Pb isotopes with ~ 14 MeV neutrons

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.

CROSS SECTION EVALUATION OF THE (n, alpha) REACTION WITH FAST NEUTRONS ON 64 Zn AND 147 Sm NUCLEI USING THE HAUSER-FESHBACH APPROACH *

Romanian Reports in Physics

In the (n,α) reactions induced by neutrons with energy about some MeV the experimental data are very poor due to the difficulty of the measurement of the cross section. In this energy region of the incident neutrons the cross section is of order of tens mb or lower for emission of charged particles. It is supposed for both nuclei that the nuclear reaction is going by formation of an intermediate compound nucleus and this is suggested by the differential cross section experimental data. For the theoretical evaluation it was used the Hauser-Feshbach approach. In this approach it is important to obtain the penetrabilities for neutron in the entrance channel and for charged particles (protons, alphas) in the exit channels. We have obtained the penetrabilities starting from quantum mechanical considerations and after that using them for obtaining the cross section. For this purpose we realized computer programs where it was implemented the regular an irregular functions in the integral f...

Calculations of (n,2n) reaction cross sections for74,76,78,80,82Se up to 20 MeV

Epj Web of Conferences, 2016

In the present work, the excitation functions of (n,2n) reactions for five isotopes of selenium (74,76,78,80,82Se) are calculated using ALICE/ASH, EMPIRE-3.2.2, PCROSS, and TALYS 1.6 computer codes based on statistical model up to 20 MeV. The theoretical calculations provide information of the (n,2n) excitation functions with the increasing target neutron number of selenium element. The calculated cross-sections were compared with experimental data from EXFOR and also with the crosssections estimated with semi empirical formula developed by Tet et al. (2008) [18]. Results show a reasonably good agreement between the calculations and the experimental data from literature.

Measurements and model calculations of activation cross sections for (n,p) reactions on 152Sm isotope between 13.57 and 14.83MeV neutrons

Applied Radiation and Isotopes, 2012

In this study, activation cross sections were measured for the reaction of 232 Th(n,2n)231Th (T 1/2 = 25.5 h) by using neutron activation technique at six different neutron energies from 13.57 and 14.83 MeV. Neutrons were produced via the 3 H(2 H,n)4He reaction using SAMES T-400 neutron generator. Irradiated and activated high purity Thorium foils were measured by a high-resolution c-ray spectrometer with a highpurity Germanium (HpGe) detector. In cross section measurements, the corrections were made for the effects of c-ray self-absorption in the foils, dead-time, coincidence summing, fluctuation of neutron flux, low energy neutrons. For this reaction, statistical model calculation, which the pre-equilibrium emission effects were taken into consideration, were also performed between 13.57 and 14.83 MeV energy range. The cross sections were compared with previous works in literature, with model calculation results, and with evaluation data bases

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.

(n,2n) and (n,3n) Neutron Induced Reaction Cross Sections above 8 MeV

Acta Physica Polonica A, 2015

Neutron induced reaction cross sections for (n,2n) and (n,3n) have been calculated in the energy range between 8 MeV and 26 MeV. Calculations were made for the target nuclei; 45 Sc, 59 Co, 89 Y, 93 Nb, 103 Rh, 169 Tm, 175 Lu, 181 Ta, 197 Au, 209 Bi. Calculated results were compared with the available data in EXFOR. Model calculations of present data indicated clearly that some reported data from measurements failed to separate (n,2n) and (n,3n) contributions.