Systematic study of the (n,2n) reaction cross section for 121Sb and 123Sb isotopes

2022 ◽  
Author(s):  
RATANKUMAR SINGH ◽  
N.L. Singh ◽  
Rakesh Chauhan ◽  
Mayur Mehta ◽  
Saraswatula suryanarayan ◽  
...  

Abstract The cross sections of the 121Sb(n,2n) 120Sbm and 123Sb(n,2n) 122Sb reactions were measured at 12.50, 15.79 and 18.87 MeV neutron energies relative to the standard 27Al(n,α) 24Na monitor reaction using neutron activation and offline γ-ray spectrometry technique. Irradiations of the samples were performed at the BARC-TIFR Pelletron Linac Facility, Mumbai, India. The quasi-monoenergetic neutron was generated via the 7Li(p,n) reaction. Statistical model calculations were performed by nuclear reaction codes TALYS (ver. 1.9) and EMPIRE (ver. 3.2.2) using various input parameters and nuclear level density models. The cross sections of the ground and the isomeric state as well as the isomeric cross section ratio were studied theoretically from reaction threshold to 26 MeV energies. The effect of pre-equilibrium emission is also discussed in detail using different theoretical models. The present measured cross section were discussed and compared with reported experimental data and evaluation data of the JEFF-3.3, ENDF/B-VIII.0, JENDL/AD-2017 and TENDL-2019 libraries. A detailed analysis of the uncertainties in the measured cross section data was performed using the covariance analysis method. Furthermore, a systematic study of the (n,2n) reaction cross section for 121Sb and 123Sb isotopes were also performed within 14-15 MeV neutron energies using various systematic formulae. This work helps to overcome discrepancies in Sb data and illustrate a better understanding of pre-equilibrium emission in (n,2n) reaction channel.

2019 ◽  
Vol 97 (11) ◽  
pp. 1206-1209
Author(s):  
Ezgi Tantoğlu ◽  
Nalan Özkan ◽  
R. Taygun Güray

There are 35 proton-rich isotopes between 74Se and 196Hg that cannot be synthesized through neutron captures and β− decays (s- and r-processes). A third process is therefore required for the production of these nuclei, the so-called p-process. The abundance and the origin of the p-nuclei are still not fully understood even though significant experimental and theoretical efforts in astrophysical modeling have been expended in the last two decades. The experimental studies with the activation method to measure cross sections of the relevant reactions have some limitations: the reaction product must be radioactive, should have an appropriate half-life, and its decay should be followed by proper γ-radiations. If the cross section cannot be calculated with the radiation followed by the first beta decay of the product, it can be measured using the second beta decay as an alternative method. In this study, the method and candidate reactions for the cross-section measurements via the second beta decay of the reaction product using the activation method are discussed.


1979 ◽  
Vol 32 (4) ◽  
pp. 335 ◽  
Author(s):  
R. J. Wilkinson ◽  
A S. R. Kennett ◽  
A Z. E. Switkowski ◽  
D. G. SargoodA and F. M. MannC

Cross sections for production of individual y rays in the 54Cr(p, y)55Mn reaction have been measured over the proton energy range 1�0-3�8 MeV. Gamma-ray yields are observed to fall by factors of between 5 and 10 at the crossing of the neutron threshold for a proton bombarding energy of 2�2 MeV. Statistical model calculations with global parameter sets successfully account for the dramatic effect of neutron competition on the (p, y) cross section, and at the same time correctly predict the 54Cr(p,n)54Mn reaction cross section.


2020 ◽  
Vol 15 ◽  
pp. 104
Author(s):  
S. Galanopoulos ◽  
R. Vlastou ◽  
P. Demetriou ◽  
M. Kokkoris ◽  
C. T. Papadopoulos ◽  
...  

Systematic experimental and theoretical investigations of the 72,73Ge(n,p)72,73 Ga and 72,74Ge(n,α)69,71Znm reaction cross sections are presented in the energy range from thresh- old to about 17 MeV neutron energy. The above reaction cross sections were measured from 8.8 to 11.4 MeV by using the activation method, relative to the 27Al(n,α)24Na refer- ence reaction. The quasi-monoenergetic neutron beams were produced via the 2H(d,n)3He reaction at the 5 MV VdG Tandem T11/25 accelerator of NCSR “Demokritos”. Statisti- cal model calculations using the code EMPIRE-II (version 2.19) taking into consideration pre-equilibrium emission were performed on the data measured in this work as well as on data reported in literature.


2019 ◽  
Vol 23 ◽  
pp. 47
Author(s):  
A. Kalamara ◽  
M. Serris ◽  
A. Spiliotis ◽  
D. Sigalos ◽  
N. Patronis ◽  
...  

Cross sections of the 174Hf(n,2n)173Hf and 176Hf(n,2n)175Hf reactions have been experimentally determined relative to the 27Al(n,α)24Na reference reaction at incident neutron energies of 15.3 and 17.1 MeV by means of the activation technique. The irradiations were carried out at the 5 MV tandem T11/25 Accelerator Laboratory of NCSR "Demokritos" with monoenergetic neutron beams provided via the 3H(d,n)4He reaction, using a new Ti-tritiated target of 373 GBq activity. In the determination of the 176Hf(n,2n)175Hf reaction cross section the contamination of the 174Hf(n,γ)175Hf and 177Hf(n,3n)175Hf reactions has been taken into account. Moreover, the neutron beam energy has been studied by means of Monte Carlo simulation codes and the neutron flux has been determined via the 27Al(n,α)24Na reference reaction.


1999 ◽  
Vol 112 (7) ◽  
pp. 743-760 ◽  
Author(s):  
V. P. Lunev ◽  
Yu. N. Shubin ◽  
C. Grandi ◽  
B. Poli ◽  
A. Ventura

2020 ◽  
Vol 29 (08) ◽  
pp. 2050062
Author(s):  
Mustafa Yiğit

Studies on the cross-sections of (n,n[Formula: see text]) reactions which are energetically possible, about 14 MeV neutrons are quite scarce. In this paper, the cross-sections of (n,n[Formula: see text] nuclear reactions at [Formula: see text]14–15 MeV are analyzed by using a new empirical formula based on the statistical theory. We show that neutron cross-sections are closely related to the [Formula: see text]-value of nuclear reaction, in particular for (n,n[Formula: see text]) channels. Results obtained with this empirical formula show good agreement with the available measured cross-section values. We hope that the estimations on the cross-sections using the present formalism may be helpful in future studies in this field.


2019 ◽  
Vol 18 ◽  
pp. 13
Author(s):  
A. Tsinganis ◽  
M. Diakaki ◽  
M. Kokkoris ◽  
A. Lagoyannis ◽  
C. T. Papadopoulos ◽  
...  

In the present work, the 197Au(n,2n) reaction cross section is studied within the framework of the Gen- eralized Superfluid Model (GSM). The cross sections for the population of the second isomeric state (12−) of 196Au and the sum of the ground (2−) and first isomeric state (5−) population cross sections were independently studied in the 8 to 25 MeV region with the use of the STAPRE-F, EMPIRE and TALYS codes, which were also compared in their implementation of the GSM. The theoretical results are compared with previous work in the same mass region and the strong dependence on the level scheme of the nuclei involved was revealed.


2009 ◽  
Vol 1 (2) ◽  
pp. 173-181 ◽  
Author(s):  
M. M. Haque ◽  
M. T. Islam ◽  
M. A. Hafiz ◽  
R. U. Miah ◽  
M. S. Uddin

The cross sections of Ge isotopes were measured with the activation method at 14.8 MeV neutron energy. The quasi-monoenergetic neutron beams were produced via the 3H(d,n)4He reaction at the 150 kV J-25 neutron generator of INST, AERE. The characteristics γ-lines of the product nuclei were measured with a closed end coaxial 17.5 cm2 high purity germanium (HPGe) detector gamma ray spectroscopy. The cross sections were determined with reference to the known 27Al(n,α)24Na reaction. Cross section data are presented for 72Ge(n,p)72Ga, 74Ge(n,α)71mZn and 76Ge(n,2n)75m+gGe reactions. The cross section values obtained for the above reactions were 24.78±1.75 mb, 1.69±0.11 mb and 860±50 mb, respectively. The results obtained were compared with the values reported in literature as well as theoretical calculation performed by the statistical code SINCROS-II. The experimental data were found fairly in good agreement with the calculated and literature data.  Keywords: Activation cross section; Neutron induced reaction; Gamma-ray spectroscopy; 14.8 MeV. © 2009 JSR Publications. ISSN: 2070-0237 (Print); 2070-0245 (Online). All rights reserved. DOI: 10.3329/jsr.v1i2.1532  


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