Testing the core-cluster model calculations for some heavy deformed nuclei

2019 ◽  
Vol 28 (07) ◽  
pp. 1950049
Author(s):  
L. I. Abou-Salem ◽  
K. E. Abdelmageed ◽  
I. A. Elmashad ◽  
R. Al Allam
Keyword(s):  
Experimental Data ◽  
Cluster Model ◽  
Theoretical Calculations ◽  
Transition Probability ◽  
Parent Nucleus ◽  
Negative Parity ◽  
Excitation Energies ◽  
Model Calculations ◽  
The Core ◽  
Core Cluster

In this work, the spectra of some even–even isotopes are studied by selecting core-cluster decomposition of the parent nucleus. The considered nuclei lie in the rare-earth and the transition metal regions. The Schrödinger equation can be solved using Bohr–Sommerfeld relation and the modified Woods–Saxon beside Coulomb potentials to reproduce the spectra of these isotopes with mass number [Formula: see text]. The theoretical calculations of the excitation energies of the ground state rotational band are compared to the experimental data. The cluster model calculations show a good agreement with the experimental data for the transitional and rotational nuclei more than the vibrational nuclei. Some negative parity bands of the chosen nuclei are studied. The core-cluster charge products are correlated with the transition probability [Formula: see text].

Energy Levels and Electromagnetic Transition of 90-94mo Nuclei Using Ibm-1

2020 ◽  
pp. 149-152
Keyword(s):  
Experimental Data ◽  
Transition Probability ◽  
Energy Levels ◽  
Dynamical Symmetry ◽  
Interacting Boson Model ◽  
Excitation Energies ◽  
Electromagnetic Transition ◽  
Boson Model ◽  
Energy States ◽  
Good Agreement

The energy states for the J , b , ɤ bands and electromagnetic transitions B (E2) values for even – even molybdenum 90 – 94 Mo nuclei are calculated in the present work of "the interacting boson model (IBM-1)" . The parameters of the equation of IBM-1 Hamiltonian are determined which yield the best excellent suit the experimental energy states . The positive parity of energy states are obtained by using IBS1. for program for even 90 – 94 Mo isotopes with bosons number 5 , 4 and 5 respectively. The" reduced transition probability B(E2)" of these neuclei are calculated and compared with the experimental data . The ratio of the excitation energies of the 41+ to 21+ states ( R4/2) are also calculated . The calculated and experimental (R4/2) values showed that the 90 – 94 Mo nuclei have the vibrational dynamical symmetry U(5). Good agreement was found from comparison between the calculated energy states and electric quadruple probabilities B(E2) transition of the 90–94Mo isotopes with the experimental data .

scholarly journals Large Scale Shell Model Calculations of the Negative-Parity States Structure in 24Mg Nucleus

2021 ◽  
Vol 66 (4) ◽  
pp. 293
Author(s):  
A.A. Al-Sammarraie ◽  
F.A. Ahmed ◽  
A.A. Okhunov
Keyword(s):  
Shell Model ◽  
Large Scale ◽  
Transition Probabilities ◽  
Transition Probability ◽  
Energy Levels ◽  
Form Factors ◽  
Model Space ◽  
Negative Parity ◽  
Matrix Elements ◽  
Model Calculations

The negative-parity states of 24Mg nucleus are investigated within the shell model. We are based on the calculations of energy levels, total squared form factors, and transition probability using the p-sd-pf (PSDPF) Hamiltonian in a large model space (0 + 1) hW. The comparison between the experimental and theoretical states showed a good agreement within a truncated model space. The PSDPF-based calculations successfully reproduced the data on the total squared form factors and transition probabilities of the negative-parity states in 24Mg nucleus. These quantities depend on the one-body density matrix elements that are obtained from the PSDPF Hamiltonian. The wave functions of radial one-particle matrix elements calculated with the harmonic-oscillator potential are suitable to predict experimental data by changing the center-of-mass corrections.

scholarly journals Statistical-model calculations for α-capture reactions relevant to the p process

2019 ◽  
Vol 26 ◽  
pp. 228
Author(s):  
C. Fakiola ◽  
I. Karakasis ◽  
I. Sideris ◽  
A. Khaliel ◽  
T. J. Mertzimekis
Keyword(s):  
Experimental Data ◽  
Statistical Model ◽  
Cross Sections ◽  
Theoretical Calculations ◽  
Reaction Network ◽  
Reaction Cross ◽  
Model Parameters ◽  
Model Calculations ◽  
Reaction Channels ◽  
Reaction Cross Sections

About 35 nuclides which lie on the neutron deficient side of the isotopic chart cannot be created by the two basic nucleosynthetic processes, the sand the rprocess. Due to scarce experimental data and the vast complexity of the reaction network involved, cross sections and reactions are estimated theoretically, using the Hauser–Feshbach statistical model. In the present work, theoretical calculations of cross sections of radiative α-capture reactions on the neutron–deficient Erbium and Xenon isotopes are presented in an attempt to make predictions inside the astrophysically relevant energy window (Gamow). The particular reactions are predicted to be sensitive branchings in the γprocess path.The most recent versions of TALYS (v1.9) and Fresco codes were employed for all calculations, initially focusing on investigating the influence of the default eight (8) α–nucleus optical potential models of TALYS on reaction cross sections. The theoretical results of both codes are compared and for the reactions where experimental data exist in literature, the optical model parameters were adjusted appropriately to best describe the data and were subsequently used for estimating (α,γ) reaction cross sections. Predictions for the (α,n) reaction channels have also been calculated and studied.

THE INTERMEDIATE ENERGY ELASTIC SCATTERING OF PROTONS BY α-CLUSTER 20Ne AND 24Mg NUCLEI

2010 ◽  
Vol 19 (02) ◽  
pp. 243-261 ◽  
Author(s):  
Yu. A. BEREZHNOY ◽  
V. P. MIKHAILYUK ◽  
V. V. PILIPENKO
Keyword(s):  
Experimental Data ◽  
Elastic Scattering ◽  
Scattering Theory ◽  
Cluster Model ◽  
Center Of Mass ◽  
Intermediate Energy ◽  
Diffraction Scattering ◽  
Multiple Diffraction ◽  
The Core ◽  
Cluster Configuration

The multiple diffraction scattering theory and the α-cluster model with dispersion have been applied for calculations of the observables for the elastic scattering of intermediate energy protons by 20 Ne and 24 Mg nuclei. The target nuclei are considered as composed of the core (16 O nucleus) and additional α-clusters (one α-cluster for 20 Ne nucleus and a dumb-bell α-cluster configuration for 24 Mg nucleus). Taking into account the α-cluster configuration of the core, it was supposed that the additional α-cluster or center of mass of the dumb-bell are arranged with the most probability inside or outside of the core. The calculated observables for the elastic p–20 Ne and p–24 Mg scattering are in agreement with the existing experimental data. The influence of the deformed core contribution on the behavior of the calculated observables also is tested.

Schalenmodellrechnungen beim Kern O18 mit geschwindigkeitsabhängigen Zwei-Teilchen-Potentialen

1967 ◽  
Vol 22 (4) ◽  
pp. 415-421
Author(s):  
Hans Grote
Keyword(s):  
Experimental Data ◽  
Harmonic Oscillator ◽  
Shell Model ◽  
Interaction Potential ◽  
Ground State ◽  
Wave Functions ◽  
Absolute Position ◽  
Model Calculations ◽  
The Core ◽  
Free Parameters

The energies of the low lying levels and the absolute position of the ground state of the nucleus O18 are calculated using five velocity-dependent potentials. The calculation is based on the shell model with two outer neutrons in the potential of the Ο16 core. The interaction potential as well as the core potential are fitted to experimental data, leaving no free parameters in the final result.The wave functions of the harmonic oscillator are used in each case of the five velocity-dependent potentials. An additional computation is carried out using one of these potentials and taking into account the perturbation of the wave functions. It turns out that, for satisfactory application of the velocity-dependent potentials in shell model calculations, this perturbation should be considered.

Synthon preference in the cocrystal of 3,4,5-trifluorophenylboronic acid with urea

2017 ◽  
Vol 73 (11) ◽  
pp. 889-895 ◽  
Author(s):  
Karolina Kopczyńska ◽  
Paulina H. Marek ◽  
Bartłomiej Banaś ◽  
Izabela D. Madura
Keyword(s):  
Crystal Structure ◽  
Experimental Data ◽  
Hydrogen Bonds ◽  
Crystal Engineering ◽  
Boronic Acid ◽  
Theoretical Calculations ◽  
Boronic Acids ◽  
Vector Model ◽  
Comprehensive Description ◽  
Model Calculations

The comprehensive description of the crystal structure of a novel 1:1 cocrystal of 3,4,5-trifluorophenylboronic acid with urea, C6H4BF3O2·CH4N2O, is presented. Both components are good candidates for crystal engineering as they can create a variety of supramolecular synthons. The preference for the formation of different hetrosynthons is verified based on theoretical calculations. The syn–anti conformation of boronic acid has been found to be the most favourable in the formation of intermolecular interactions with urea. Moreover, the distortions present in the boron coordination sphere have been described quantitatively based on experimental data according to bond-valence vector model calculations. The results revealed that the deformation of the sphere is typical for a syn–anti conformation of boronic acids. The supramolecular structure of the cocrystal is composed of large synthons in the form of layers made up of O—H...O and N—H...O hydrogen bonds. The layers are joined via N—H...F hydrogen bonds which are unusual for urea cocrystal structures.

Binary cluster model calculations for 20Ne and 44Ti nuclei

2017 ◽  
Vol 32 (09) ◽  
pp. 1750050 ◽  
Author(s):  
F. Koyuncu ◽  
A. Soylu ◽  
O. Bayrak
Keyword(s):  
Cluster Model ◽  
Transition Probabilities ◽  
Cluster Structure ◽  
Scattering Data ◽  
Nuclear Potential ◽  
Heavy Nuclei ◽  
Excitation Energies ◽  
Model Calculations ◽  
Electromagnetic Transition ◽  
Decay Widths

The elastic scattering data of [Formula: see text] and [Formula: see text] systems at [Formula: see text] = 32.2–146 MeV and [Formula: see text] = 24.1–49.5 MeV energies have been analyzed with double-folding (DF) potential in optical model formalism in order to investigate the cluster structures of [Formula: see text]Ne and [Formula: see text]Ti nuclei. The deduced DF potentials between [Formula: see text] and [Formula: see text]O as well as [Formula: see text] and [Formula: see text]Ca have been used for obtaining the excitation energies and [Formula: see text]-decay widths of [Formula: see text]Ne and [Formula: see text]Ti in Gamow code, but the reasonable results could not be obtained. Thus, the real parts of DF potentials which are in the best agreement with experimental data have been fitted with the squared-Woods–Saxon (WS2) potential parameters to calculate the [Formula: see text]-decay widths of [Formula: see text]Ne and [Formula: see text]Ti with Wentzel–Kramers–Brillouin (WKB) approach. The nuclear potential sets obtained in WKB calculations are also used for Gamow code calculations. We take into account the deformation and orientation of [Formula: see text]Ca nucleus to examine their influence on both the excitation energies and decay widths of [Formula: see text]Ti. Besides, by using the binary cluster model the rotational band energies and electromagnetic transition probabilities (BE2)s according to angles are also reproduced for both nuclei. The obtained results showed that the binary cluster model is very useful to understand the observables of [Formula: see text]Ne and [Formula: see text]Ti nuclei. Although only spherical calculations are made for [Formula: see text]Ne ([Formula: see text] + [Formula: see text]O), the deformation in [Formula: see text]Ca would be important for the understanding of [Formula: see text]Ti ([Formula: see text] + [Formula: see text]Ca) cluster structure. The mechanism presented here would also be applied to understand the cluster structures in heavy nuclei.

scholarly journals Theoretical calculations for the reaction 241Am(n, 2n) in the framework of the Hauser-Feshbach model

2019 ◽  
Vol 14 ◽  
pp. 83
Author(s):  
G. Perdikakis ◽  
C. T. Papadopoulos ◽  
M. Kokkoris ◽  
R. Vlastou
Keyword(s):  
Experimental Data ◽  
Cross Section ◽  
Theoretical Calculations ◽  
Fission Cross Section ◽  
Tandem Accelerator ◽  
Accelerator Facility ◽  
Model Calculations ◽  
First Results ◽  
Induced Fission ◽  
Comparison With Experimental Data

The cross section of the reaction 2ilAm(n, 2n), has been measured by the activation method in the range from 9.6 to 11.4 MeV, at the Tandem accelerator facility of NCSR Demokritos. Statistical model calculations in the framework of the Hauser- Feshbach theory have been performed, and the first results are presented. Experimental data on the neutron induced fission cross section of 241Am, have been used as a constraint for the calculations. The results of the investigation are presented in comparison with experimental data and previous theoretical evaluations.

Collective bands in 80,82Kr

2007 ◽  
Vol 85 (3) ◽  
pp. 269-278 ◽  
Author(s):  
S Mishra ◽  
K C Tripathy ◽  
R Sahu
Keyword(s):  
Experimental Data ◽  
Angular Momentum ◽  
Configuration Space ◽  
Negative Parity ◽  
Model Calculations ◽  
Ground Band ◽  
Particle Orbits ◽  
Inert Core ◽  
21.60 Jz ◽  
Different Levels

Deformed shell-model calculations are performed to study the structure of the collective bands in 80,82Kr. In our microscopic model, the single particle orbits 1p3/2, 0f5/2, 1p1/2, and 0g9/2 constitute the configuration space with 56Ni as the inert core. A modified Kuo interaction for this basis space is used in our calculation. The different levels are classified into collective bands on the basis of the B(E2) values among them. The calculated ground bands and quasi-gamma bands for both the nuclei agree reasonably well with experiment. The negative parity bands are also well-reproduced in our calculation. The calculated B(E2) values are compared with available experimental data. The nature of angular momentum alignment in the ground band is also discussed. PACS Nos.: 21.10.–k, 21.60.Jz, 27.50.+e

scholarly journals Nuclear structure study of [22,24]Ne and [24]Mg nuclei

2019 ◽  
Vol 65 (2) ◽  
pp. 159
Author(s):  
Fouad A. Majeed ◽  
And Sarah M. Obaid
Keyword(s):  
Experimental Data ◽  
Shell Model ◽  
Nuclear Structure ◽  
Transition Probabilities ◽  
Form Factors ◽  
Model Space ◽  
High Energy ◽  
Core Polarization ◽  
Model Calculations ◽  
The Core

Shell model calculations based on large basis has been conducted to study the nuclear structure of $^{20}Ne$, $^{22}Ne$ and $^{24}Mg$ nuclei. The energy levels, inelastic electron scattering form factors and transition probabilities are discussed by considering the contribution of  configurations with high-energy beyond the model space of sd-shell model space which is denoted as the core polarization (CP) effects.~The Core polarization is considered by taking the excitations of nucleus from the $1s$ and $1p$ core orbits and also from the valence $2s$ $1d$ shell orbit in to higher shells with $4\hbar\omega$. The effective interactions $USDA$ and $USDB$ are employed with $sd$ shell model space to perform the calculation and the core polarization are calculated with $MSDI$ as residual interaction.~The calculated energy level schemes,  form factors and transition probabilities were compared with the corresponding experimental data. The effect of core polarization is found very important for the calculation of $B(C2)$, $B(C4)$ and form factors, and gives excellent results in comparison with the experimental data without including any adjustable parameters.

Sign in / Sign up

Export Citation Format

Share Document