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Non-Resonant Reaction Rates of 13C(α,n)16O and 22Ne(α,n)25Mg reactions in AGB Stars
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Both 13C 16O and 22Ne 25Mg reactions perform a cosmic role in the production of neutrons in AGB stars, which significantly contributes to the nucleosynthesis via the s-process. The astrophysical S-factor for both reactions is calculated in this research, utilizing EMPIRE code and depending on two parameter sets for the optical potential. These datasets were published earlier by McFadden and Satchler (denoted here as MFS) and Avrigeanu and Hodgson (denoted as AH) for the non-resonant region of the spectrum and over a temperature range of . The extrapolated S-factor at zero energy is derived to be  and  for 13C 16O, while the values were  and  for 22Ne 25Mg, using MFS and AH parameter sets, respectively, which showed a reasonable agreement with the most recommended value. The differences in the S-factor, S(E), values obtained from these two adopted parameter sets are attributed to the variations of the real potential term's diffuseness parameter that affects the reaction cross section, hence S-factor, specifically at low energy region. Moreover, the present results imply an influential enhancement of the rates by the electron shielding effect at the low-temperature region  in which 13C 16O reaction is activated,  especially on 22Ne 25Mg reaction. In addition, for both adopted reactions and overall selected temperature range, the reaction rates using  values based on MFS showed acceptable results compared with previous compilations and reference libraries. While the results obtained from AH exceeded all the other compilations even though the resonance contributions are currently unconsidered.

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Publication Date
Thu Apr 27 2017
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
Determining of Cross Sections for 16O(n,α)13C reaction from Cross Sections of 13C(α,n)16O for the ground state
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  In this study, light elements for 13C , 16O for  (α,n) and (n,α) reactions as well as α-particle energy  from 2.7 MeV  to 3.08 MeV are used as far as the data of reaction cross sections are available. The more recent cross sections data of (α,n) and (n,α) reactions are reproduced in fine steps 0.02 MeV for  16O (n,α) 13C  in the specified energy range, as well as cross section (α,n)  values were derived from the published data of (n,α) as a function of α-energy in the same fine energy steps by using the principle inverse reactions. This calculation involves only the ground state of  13C , 16O  in the reactions 13C (α,n) 16O  and  16O (n,α) 13C.

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Publication Date
Thu Sep 01 2022
Journal Name
Neuroquantology
Reaction Cross Section Variations of (alpha + 22Ne) in Msun<M<4Msun AGB Stars
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Publication Date
Fri Jan 01 2010
Journal Name
Ibn Al- Haitham J. Fo R Pure & Appl. Sci
Evaluation of The Nuclear Data on(α,n)Reaction for Natural Molybdenum
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The cross section evaluation for (α,n) reaction was calculated according to the available International Atomic Energy Agency (IAEA) and other experimental published data . These cross section are the most recent data , while the well known international libraries like ENDF , JENDL , JEFF , etc. We considered an energy range from threshold to 25 M eV in interval (1 MeV). The average weighted cross sections for all available experimental and theoretical(JENDL) data and for all the considered isotopes was calculated . The cross section of the element is then calculated according to the cross sections of the isotopes of that element taking into account their abundance . A mathematical representative equation for each of the element

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Publication Date
Wed Sep 01 2021
Journal Name
Iraqi Journal Of Physics
Theoretical Calculations of the Cross-sections for (n,α) and (n,xα) reactions on the Structural Material for Fusion Reactor 46-50Ti
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The biggest problem of structural materials for fusion reactor is the damage caused by the fusion product neutrons to the structural material. If this problem is overcomed, an important milestone will be left behind in fusion energy. One of the important problems of the structural material is that nuclei forming the structural material interacting with fusion neutrons are transmuted to stable or radioactive nuclei via (n, x) (x; alpha, proton, gamma etc.) reactions. In particular, the concentration of helium gas in the structural material increases through deuteron- tritium (D-T) and (n, α) reactions, and this increase significantly changes the microstructure and the properties of the structural materials. T

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Publication Date
Fri Jan 26 2024
Journal Name
Iraqi Journal Of Science
Conclusion Empirical Equations of Asymmetry Parameter for Magic Nuclei in N for()α,n Reaction of Incident Neutron Energy (14.5 MeV)
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In this study, the magic nuclei is divided into two groups, one of them is light group and the other is middle group, it was calculated shell corrections for all nuclei, and also it was concluded the relationship between cross sections for nuclear reactions ()α,n and the mass number (A) for all nuclei to incident neutrons (14.5 MeV). We found empirical equations to asymmetry parameter (N-Z)/A as function of mass number and for that two groups: for A=38 to A=40 light nuclei.()0534.10263.0+−=−AAZN for A=50 to A=89 middle nuclei. ()408.00151.00001.02−+=−AAAZN for A=90 to A=144 middle nuclei. ()0711.10221

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Publication Date
Tue Sep 11 2018
Journal Name
Iraqi Journal Of Physics
An experimental cross-section measurement of 10B(n,α)7Li reaction on counting alpha particles track density
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The present work determines the particle size based only on the number of tracks detected in a cluster created by a hot particle on the CR-39 solid state nuclear track detector and depending on the exposure time. The mathematical model of the cross section developed here gives the relationship between alpha particle emitting from the (n, α) reaction and the number of tracks created and distribution of tracks created on the surface of the track detector. In an experiment performed during this work, disc of boron compound (boric acid or sodium tetraborate) of different weights were prepared and exposed to thermal neutron from the source. Chemical etching is processes of path formation in the detector, during which a suitable etching solut

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Publication Date
Wed Mar 01 2023
Journal Name
Iraqi Journal Of Physics
Evaluation of Resonance Strengths and Reaction Rates of 22Ne (p, gamma) 23Na Nuclear Reaction at Thermonuclear Energies
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At thermal energies near stellar conditions, nuclear reactions are sensitive to resonance strengths of the nuclear reaction cross-section. In this paper, the resonance strengths of  nuclear reaction were evaluated numerically by means of nuclear reaction rate calculations using a written Matlab code, at the energies of interest in stellar nuclear reactions. The results were compared with standard reaction before and after application of a statistical analyses, to select the best parameters that made theoretical results as close as possible to the standard values. Fitting was made for different temperature ranges up to 10 GK, 0.6 GK and 0.25 GK. The evaluated results showed that as the temperature range becomes narrower, more error is ad

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Publication Date
Sat Dec 01 2012
Journal Name
Iraqi Journal Of Science
The Effect of Metallicity on the AGB Stars Evolution by Using Synthetic Model
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Abstract: Stars whose initial masses are between (0.89 - 8.0) M☉ go through an Asymptotic Giant Branch (AGB) phase at the end of their life. Which have been evolved from the main sequence phase through Asymptotic Giant Branch (AGB). The calculations were done by adopted Synthetic Model showed the following results: 1- Mass loss on the AGB phase consists of two phases for period (P <500) days and for (P>500) days; 2- the mass loss rate exponentially increases with the pulsation periods; 3- The expansion velocity VAGB for our stars are calculated according to the three assumptions; 4- the terminal velocity depends on several factors likes metallicity and luminosity. The calculations indicated that a super wind phase (S.W) developed on the A

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Publication Date
Sat Sep 30 2023
Journal Name
Iraqi Journal Of Science
Generalized Pre α-Regular and Generalized Pre α-Normal Spaces in Topological Spaces
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     The concept of separation axioms constitutes a key role in general topology and all generalized forms of topologies. The present authors continued the study of gpα-closed sets by utilizing this concept, new separation axioms, namely gpα-regular and gpα-normal spaces are studied and established their characterizations. Also, new spaces namely gpα-Tk  for k = 0, 1, 2 are studied.

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Publication Date
Sat Mar 11 2017
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
Spectrophotometric Determination of Sulfamethoxazole with P-N,N-dimethyl amino benzaldehyde as Condensation Reaction
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Sulfamethoxazole (SMX) was added to P-N,N-dimethyl amino benzaldehyde (PDAB) by condensation reaction in acidic medium to form, a yellow colored dye compound which exhibits maximum absorption (λmax) at 450.5 nm. The concentration of (SMX) was determined spectrophotometrically. The optimum reaction conditions and other analytical parameters were evaluated. In addition to classical univariate optimization, design of experiment method has been applied in optimization of the variables affecting the color producing reaction.    Beer’s law obeyed in the concentration range of 0.1-10 μg.mL-1 with molar absorptivity of 5.7950×104  L.mol-1.cm-1. The limit of detection and Sandell's sensitivity value were 0.078 μ

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