PREDICTING NUCLEAR MASSES BY IMAGE RECONSTRUCTION

2006 ◽  
Vol 15 (08) ◽  
pp. 1855-1867 ◽  
Author(s):  
IRVING MORALES ◽  
ALEJANDRO FRANK ◽  
JUAN CARLOS LÓPEZ-VIEYRA ◽  
JOSÉ BAREA ◽  
JORGE G. HIRSCH ◽  
...  
Keyword(s):  
Fourier Transform ◽  
Liquid Drop ◽  
Nuclear Deformation ◽  
Two Dimensional ◽  
Deconvolution Method ◽  
Liquid Drop Model ◽  
Unstable Nuclei ◽  
Shell Closures ◽  
Nuclear Masses ◽  
Potential Applications

The differences between measured masses and Liquid Drop Model (LDM) predictions have well known regularities, which can be analyzed as a two-dimensional texture on the N-Z plane. The remaining microscopic effects, obtained after removing the smooth LDM mass contributions, have proved difficult to model. They contain all the information related to shell closures, nuclear deformation and the residual nuclear interactions, and display a well defined pattern. In the present work the more than 2000 known nuclear masses are studied as an array in the N-Z plane viewed through a mask, behind which the approximately 7000 unknown unstable nuclei that can exist between the proton and neutron drip lines are hidden. Employing a Fourier transform deconvolution method these masses can be predicted. Measured masses are reconstructed with and r.m.s. error of less than 100 keV. Potential applications of the present approach are outlined.

scholarly journals MODIFIED BETHE–WEIZSÄCKER MASS FORMULA WITH ISOTONIC SHIFT AND NEW DRIPLINES

2005 ◽  
Vol 20 (21) ◽  
pp. 1605-1618 ◽  
Author(s):  
P. ROY CHOWDHURY ◽  
C. SAMANTA ◽  
D. N. BASU
Keyword(s):  
Mass Formula ◽  
Liquid Drop ◽  
Macroscopic Model ◽  
Liquid Drop Model ◽  
Nuclear Masses

Nuclear masses are calculated using the modified Bethe–Weizsäcker mass formula in which the isotonic shifts have been incorporated. The results are compared with the improved liquid drop model with isotonic shift. Mass excesses predicted by this method compares well with the microscopic–macroscopic model while being much more simple. The neutron and proton drip lines have been predicted using this modified Bethe–Weizsäcker mass formula with isotonic shifts.

PREDICTIONS OF NUCLEAR MASSES IN DIFFERENT MODELS

2007 ◽  
Vol 16 (02) ◽  
pp. 474-482 ◽  
Author(s):  
BOŻENA NERLO–POMORSKA ◽  
KRZYSZTOF POMORSKI ◽  
MONIKA ZWIERZCHOWSKA
Keyword(s):  
Field Theory ◽  
Liquid Drop ◽  
Mean Field Theory ◽  
Mean Field ◽  
Liquid Drop Model ◽  
Hartree Fock ◽  
Relativistic Mean Field ◽  
Bogoliubov Theory ◽  
Nuclear Masses ◽  
Nuclear Stability

The modern version of the liquid-drop model is compared to the macroscopic Thomas-Fermi (TF) energy and the macroscopic part of the binding energy evaluated within the Hartree-Fock-Bogoliubov theory with the Gogny force and the relativistic mean field theory. The limits of nuclear stability predicted by these models are discussed.

THE ART OF PREDICTING NUCLEAR MASSES

2008 ◽  
Vol 17 (supp01) ◽  
pp. 398-411 ◽  
Author(s):  
JORGE G. HIRSCH ◽  
IRVING MORALES ◽  
JOEL MENDOZA-TEMIS ◽  
ALEJANDRO FRANK ◽  
JUAN CARLOS LOPEZ-VIEYRA ◽  
...  
Keyword(s):  
Theoretical Analysis ◽  
Predictive Model ◽  
Iterative Process ◽  
Short Range ◽  
Mass Formula ◽  
Predictive Power ◽  
Liquid Drop ◽  
Liquid Drop Model ◽  
Nuclear Mass ◽  
Nuclear Masses

A review of recent advances in the theoretical analysis of nuclear mass models and their predictive power is presented. After introducing two tests which probe the ability of nuclear mass models to extrapolate, three models are analyzed in detail: the liquid drop model (LDM), the liquid drop model plus empirical shell corrections (LDMM) and the Duflo–Zuker mass formula (DZ). The DZ model is exhibited as the most predictive model. The Garvey–Kelson mass relations are also discussed. It is shown that their fulfillment probes the consistency of the most commonly used mass formulae, and that they can be used in an iterative process to predict nuclear masses in the neighborhood of nuclei with measured masses, offering a simple and reproducible procedure for short range mass predictions.

ALPHA DECAY HALF-LIVES OF EXOTIC NUCLEI AROUND SHELL CLOSURES

2011 ◽  
Vol 20 (01) ◽  
pp. 127-138 ◽  
Author(s):  
Y. Z. WANG ◽  
Q. F. GU ◽  
J. M. DONG ◽  
B. B. PENG
Keyword(s):  
Liquid Drop ◽  
Alpha Decay ◽  
Exotic Nuclei ◽  
Future Research ◽  
Liquid Drop Model ◽  
Α Decay ◽  
Shell Closures ◽  
Experimental Values ◽  
Closed Shells ◽  
Good Agreement

In the framework of the generalized liquid drop model (GLDM) and improved Royer's formula with a set of new coefficients derived by N. D. Schubert et al. [Eur. Phys. J. A42 (2009) 121], the favored and unfavored α-decay half-lives of exotic nuclei around closed shells Z = 82 and N = 126 are investigated. The calculated results are in good agreement with the experimental data. It is shown that our method can be used to study the α-decay half-lives of exotic nuclei around shell closures successfully and is helpful for future research on superheavy nuclei around the next proton and neutron shell closures. In addition, some α-decay half-lives for the cases where the experimental values are unavailable are predicted. We hope our predicted results are useful for future experiments.

Comparison of Calculated and Recorded Electron Energy-Loss Spectra of Aluminium and Carbon

1990 ◽  
Vol 48 (2) ◽  
pp. 64-65
Author(s):  
L. Reimer ◽  
R. Oelgeklaus
Keyword(s):  
Fourier Transform ◽  
Energy Loss ◽  
Electron Energy ◽  
Rotational Symmetry ◽  
Mean Free Path ◽  
Single Scattering ◽  
Specimen Thickness ◽  
Two Dimensional ◽  
Image Position ◽  
Electron Energy Loss

Quantitative electron energy-loss spectroscopy (EELS) needs a correction for the limited collection aperture α and a deconvolution of recorded spectra for eliminating the influence of multiple inelastic scattering. Reversely, it is of interest to calculate the influence of multiple scattering on EELS. The distribution f(w,θ,z) of scattered electrons as a function of energy loss w, scattering angle θ and reduced specimen thickness z=t/Λ (Λ=total mean-free-path) can either be recorded by angular-resolved EELS or calculated by a convolution of a normalized single-scattering function ϕ(w,θ). For rotational symmetry in angle (amorphous or polycrystalline specimens) this can be realised by the following sequence of operations :(1)where the two-dimensional distribution in angle is reduced to a one-dimensional function by a projection P, T is a two-dimensional Fourier transform in angle θ and energy loss w and the exponent -1 indicates a deprojection and inverse Fourier transform, respectively.

scholarly journals A First-Principle Study of Monolayer Transition Metal Carbon Trichalcogenides

2021 ◽  
Author(s):  
Muhammad Yar Khan ◽  
Yan Liu ◽  
Tao Wang ◽  
Hu Long ◽  
Miaogen Chen ◽  
...  
Keyword(s):  
Phonon Dispersion ◽  
Magnetic Ordering ◽  
Dimensional Structure ◽  
First Principle ◽  
Two Dimensional ◽  
Biaxial Strain ◽  
Half Metallic ◽  
First Principle Calculations ◽  
Potential Applications ◽  
External Strain

AbstractMonolayer MnCX3 metal–carbon trichalcogenides have been investigated by using the first-principle calculations. The compounds show half-metallic ferromagnetic characters. Our results reveal that their electronic and magnetic properties can be altered by applying uniaxial or biaxial strain. By tuning the strength of the external strain, the electronic bandgap and magnetic ordering of the compounds change and result in a phase transition from the half-metallic to the semiconducting phase. Furthermore, the vibrational and thermodynamic stability of the two-dimensional structure has been verified by calculating the phonon dispersion and molecular dynamics. Our study paves guidance for the potential applications of these two mono-layers in the future for spintronics and straintronics devices.

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