scholarly journals 14.8 MeV Neutron Activation Cross Section Measurements for Ge Isotopes

2009 ◽  
Vol 1 (2) ◽  
pp. 173-181 ◽  
Author(s):  
M. M. Haque ◽  
M. T. Islam ◽  
M. A. Hafiz ◽  
R. U. Miah ◽  
M. S. Uddin
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Gamma Ray ◽  
Reaction Cross ◽  
Activation Cross Section ◽  
Section Data ◽  
Gamma Ray Spectroscopy ◽  
24Na Reaction ◽  
The Cross ◽  
Good Agreement

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  

scholarly journals Activation cross section of the (n,2n) reaction on Hf isotopes

2019 ◽  
Vol 23 ◽  
pp. 47
Author(s):  
A. Kalamara ◽  
M. Serris ◽  
A. Spiliotis ◽  
D. Sigalos ◽  
N. Patronis ◽  
...  
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Reaction Cross Section ◽  
Beam Energy ◽  
Reaction Cross ◽  
Activation Technique ◽  
Incident Neutron ◽  
Activation Cross Section ◽  
Reference Reaction

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.

Reaction cross section calculations via second beta decay using the activation method for the p-process

2019 ◽  
Vol 97 (11) ◽  
pp. 1206-1209
Author(s):  
Ezgi Tantoğlu ◽  
Nalan Özkan ◽  
R. Taygun Güray
Keyword(s):  
Beta Decay ◽  
Cross Section ◽  
Cross Sections ◽  
Half Life ◽  
Reaction Cross Section ◽  
Experimental Studies ◽  
Reaction Cross ◽  
Activation Method ◽  
Alternative Method ◽  
The Cross

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.

A new empirical formula for cross-sections of (n,nα) reactions

2020 ◽  
Vol 29 (08) ◽  
pp. 2050062
Author(s):  
Mustafa Yiğit
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Empirical Formula ◽  
Nuclear Reactions ◽  
Measured Cross Section ◽  
Future Studies ◽  
Present Formalism ◽  
The Cross ◽  
Neutron Cross Sections ◽  
Good Agreement

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.

scholarly journals Cross Section Ionization By Electron Impact Of Helium Like Ions

2021 ◽  
Author(s):  
Manel Hariz Belgacem ◽  
Elhabib Guedda ◽  
Haikel Jelassi
Keyword(s):  
Electron Impact ◽  
Cross Section ◽  
Cross Sections ◽  
Ground State ◽  
The Cross ◽  
State 1 ◽  
Unstable States ◽  
Good Agreement

<sub></sub> In this paper we present our calculation of the cross section ionization by electron impact of C V, N VI and O VII. Using the Flexible Atomic Code (FAC), we obtain the cross sections for the ionization of these ions from the ground state 1<sup>1</sup>S, and from the unstable states 2<sup>1</sup>S and 2<sup>3</sup>S. Our results are in good agreement with those based on the Coulomb Born (CB) approximation and the available measurements.

scholarly journals On the Experimental Investigation of the Angular Distributions in the Reaction 112Cd(p,γ)113In

2019 ◽  
Vol 26 ◽  
pp. 188
Author(s):  
A. Zyriliou ◽  
A. Khaliel ◽  
T. J. Mertzimekis
Keyword(s):  
Cross Sections ◽  
Nuclear Physics ◽  
Gamma Ray ◽  
Reaction Cross ◽  
Angular Distributions ◽  
Special Focus ◽  
Tandem Accelerator ◽  
Section Data ◽  
Hpge Detectors ◽  
Low Energies

Some of the mid–weight nuclei lie in the region of the isotopic chart where the astrophysical p-process has a prominent role in the nucleosynthetic scenarios. Experimentally deduced reaction cross section data can provide stringent tests for the astrophysical models, especially at low energies. In this framework, the reaction 112Cd(p,γ)113In has been studied experimentally at four proton beam energies 2.8 ≤ Ep≤ 3.4 MeV, partly inside the astrophysically interesting Gamow window. Proton beams were provided by the 5.5 MV T11 Van de Graaff Tandem Accelerator of the Institute of Nuclear Physics of the National Center for Scientific Research (NCSR) “Demokritos”. In–beam spectroscopy was carried out with an array of four HPGe detectors sitting on a rotating table. In total, eight (8) different angles were used to record gamma–ray spectra. Special focus was given on constructing the angular distribution of each gamma–ray feeding the ground state of 113In directly, so as to determine the reaction cross sections from the in–beam data, exclusively. The resulting cross sections were compared to Hauser–Feshbach calculations using the code TALYS v1.9.

New empirical formula for calculating (n,p) reaction cross-sections at 14.5MeV neutrons

2020 ◽  
Vol 29 (08) ◽  
pp. 2050052
Author(s):  
Dashty T. Akrawy ◽  
Ali H. Ahmed ◽  
E. Tel ◽  
A. Aydin ◽  
L. Sihver
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Empirical Formula ◽  
Nuclear Data ◽  
Reaction Cross ◽  
Section Data ◽  
Nuclear Data Library ◽  
Number Formula ◽  
New Formula ◽  
Reaction Cross Sections

An empirical formula to calculate the ([Formula: see text], [Formula: see text] reaction cross-sections for 14.5[Formula: see text]MeV neutrons for 183 target nuclei in the range [Formula: see text] is presented. Evaluated cross-section data from TENDL nuclear data library were used to test and benchmark the formula. In this new formula, the nonelastic cross-section term is replaced by the atomic number [Formula: see text], while the asymmetry parameter-dependent exponential term has been retained. The calculated results are presented in comparison with the seven previously published formulae. We show that the new formula is significantly in better agreement with the measured values compared to previously published formulae.

Cross-section measurements of the (n,2n) and (n,p) reactions on 124,126,128,130,131,132Xe in the 14 MeV region and theoretical calculations of their excitation functions

2021 ◽  
Author(s):  
Junhua Luo ◽  
Li Jiang ◽  
junchen liang ◽  
Fei Tuo ◽  
Long He ◽  
...  
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Theoretical Calculations ◽  
Germanium Detector ◽  
Reaction Model ◽  
Reaction Cross ◽  
Model Parameters ◽  
China Academy ◽  
The Cross ◽  
Data Libraries

Abstract The reaction cross-sections of 124Xe(n, 2n)123Xe, 126Xe(n, 2n)125Xe, 128Xe(n, 2n)127Xe, 130Xe(n, 2n)129mXe, 132Xe(n, 2n)131mXe, 130Xe(n, p)130I, 131Xe(n, p)131I, and 132Xe(n, p)132I were measured at the 13.5, 13.8, 14.1, 14.4, and 14.8 MeV neutron energies. The monoenergetic neutrons were generated through the 3H(d,n)4He reaction at the China Academy of Engineering Physics using the K-400 Neutron Generator with a solid 3H-Ti target. A high-purity germanium detector was used to measure the activities of the product. The reactions 93Nb(n, 2n)92mNb and 27Al(n, α)24Na served for neutron flux calibration. The cross sections of the (n,2n) and (n,p) reactions of the xenon isotopes were acquired within the 13–15 MeV neutron energy range. These cross-sections were then compared with the IAEA-exchange format (EXFOR) database-derived experimental data together with the evaluation results of the CENDL-3, ENDF/B-VIII.0, JENDL-4.0, RUSFOND, and JEFF-3.3 data libraries as well as the theoretical excitation function obtained using the TALYS-1.95 code. The cross-sections of the reactions (except for the 124Xe(n, 2n)123Xe and 132Xe(n, p)132I) at 13.5, 13.8, and 14.1 MeV are reported for the first time in this work. The present results are helpful to provide better cross-section constraints for these reactions in the 13–15 MeV region, thus improving the quality of the corresponding database. Meanwhile, these data can also be used for the verification of relevant nuclear reaction model parameters.

Notizen: Empirical Evidence for Shell Effects in (n,p)- and (n,α)-Reaction Cross Sections Induced By 14 Mev Neutrons

1972 ◽  
Vol 27 (6) ◽  
pp. 1015-1016 ◽  
Author(s):  
P. Holmberg
Keyword(s):  
Empirical Evidence ◽  
Cross Section ◽  
Cross Sections ◽  
Shell Structure ◽  
Closed Shell ◽  
Reaction Cross ◽  
Shell Effects ◽  
The Cross ◽  
Closed Shells ◽  
Reaction Cross Sections

Abstract Cross section values for (n,p)-and (n,α)-reactions have been analysed as functions of the proton and neutron numbers of the target nuclei. When these numbers equal or approach those of a closed shell structure, the cross section values tend to increase. Far from closed shells the cross sections are small.

On a model for a time series of cross-sections

1986 ◽  
Vol 23 (A) ◽  
pp. 113-125 ◽  
Author(s):  
P. M. Robinson
Keyword(s):  
Time Series ◽  
Cross Section ◽  
Cross Sections ◽  
Standard Form ◽  
Cross Sectional ◽  
Aggregated Data ◽  
Section Data ◽  
Infinite Population ◽  
The Cross ◽  
Observation Times

Dynamic stationary models for mixed time series and cross-section data are studied. The models are of simple, standard form except that the unknown coefficients are not assumed constant over the cross-section; instead, each cross-sectional unit draws a parameter set from an infinite population. The models are framed in continuous time, which facilitates the handling of irregularly-spaced series, and observation times that vary over the cross-section, and covers also standard cases in which observations at the same regularly-spaced times are available for each unit. A variety of issues are considered, in particular stationarity and distributional questions, inference about the parameter distributions, and the behaviour of cross-sectionally aggregated data.

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