arXiv subjects

D. N. Basu

Publications and source records attributed to D. N. Basu.

85 records · Page 5Linked to original sources

arXiv2004

Equation of state for nuclear matter based on density dependent effective interaction

An interesting method of obtaining equation of state for nuclear matter, from a density dependent M3Y interaction, by minimizing the energy per nucleon is described. The density dependence parameters of the interaction are obtained by reproducing the saturation energy per nucleon and the saturation density of spin and isospin symmetric cold infinite nuclear matter. The nuclear matter equation of state thus obtained is then used to calculate the pressure, the energy density, the nuclear incompressibility and the velocity of sound in nuclear medium. The results obtained are in good agreement with experimental data and provide a unified description of radioactivity, scattering and nuclear matter.

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arXiv2004

Neutron and proton drip lines using the modified Bethe-Weizsacker mass formula

Proton and neutron separation energies have been calculated using the extended Bethe-Weizsacker mass formula. This modified Bethe-Weizsacker mass formula describes minutely the positions of all the old and the new magic numbers. It accounts for the disappearance of some traditional magic numbers for neutrons and provides extra stability for some new neutron numbers. The neutron and proton drip lines have been predicted using this extended Bethe-Weizsacker mass formula. The implications of the proton drip line on the astrophysical rp-process and of the neutron drip line on the astrophysical r-process have been discussed.

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arXiv2004

Lifetimes of the $α$ decay chains of superheavy element 115

The lifetimes of the consecutive $α$ decay chains of recently synthesized new element 115, $^{287}115$ and $^{288}115$, have been calculated theoretically within the WKB approximation using microscopic $α$-nucleus interaction potentials obtained by folding in the densities of the $α$ and the daughter nuclei with a realistic effective interaction. M3Y effective interaction, supplemented by a zero-range pseudo-potential for exchange along with the density dependence, has been used for calculating the nuclear interaction potentials. Spherical charge distributions have been used for calculating the Coulomb interaction potentials. These calculations provide consistent estimates for the lifetimes of the consecutive $α$ decay chains of the superheavy element 115.

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arXiv2003

On the extension of the Bethe-Weizsacker mass formula to light nuclei

Some general features of the Bethe-Weizsacker mass formula recently extended to light nuclei have been explored. Though this formula improves fits to the properties of light nuclei and it does seem to work well in delineating the positions of all old and new magic numbers found in that region, yet it is not well tuned for predicting finer details. The mass predictions have also been found to be less accurate compared to those by the macroscopic-microscopic calculations. It is concluded that such semi-empirical mass formulae can not be a substitute for more fundamental mass formulae having its origin based upon the basic nucleon-nucleon effective interaction.

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arXiv2003

Nuclear incompressibility using the density dependent M3Y effective interaction

A density dependent M3Y effective nucleon-nucleon (NN) interaction which was based on the G-matrix elements of the Reid-Elliott NN potential has been used to determine the incompressibity of infinite nuclear matter. The nuclear interaction potential obtained by folding in the density distribution functions of two interacting nuclei with this density dependent M3Y effective interaction had been shown earlier to provide excellent descriptions for medium and high energy $α$ and heavy ion elastic scatterings as well as $α$ and heavy cluster radioactivities. The density dependent parameters have been chosen to reproduce the saturation energy per nucleon and the saturation density of spin and isospin symmetric cold infinite nuclear matter. The result of such calculations for nuclear incompressibility using the density dependent M3Y effective interaction based on the G-matrix elements of Reid-Elliott NN potential predicts a value of about 300 MeV for nuclear incompressibility.

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arXiv2003

Folding model analysis of alpha radioactivity

Radioactive decay of nuclei via emission of $α$ particles has been studied theoretically in the framework of a superasymmetric fission model using the double folding (DF) procedure for obtaining the $α$-nucleus interaction potential. The DF nuclear potential has been obtained by folding in the density distribution functions of the $α$ nucleus and the daughter nucleus with a realistic effective interaction. The M3Y effective interaction has been used for calculating the nuclear interaction potential which has been supplemented by a zero-range pseudo-potential for exchange along with the density dependence. The nuclear microscopic $α$-nucleus potential thus obtained has been used along with the Coulomb interaction potential to calculate the action integral within the WKB approximation. This subsequently yields microscopic calculations for the half lives of $α$ decays of nuclei. The density dependence and the exchange effects have not been found to be very significant. These calculations provide reasonable estimates for the lifetimes of $α$ radioactivity of nuclei.

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arXiv2003

Role of effective interaction in nuclear disintegration processes

A simple superasymmetric fission model using microscopically calculated nuclear potentials has shown itself to be outstandingly successful in describing highly asymmetric spontaneous disintegration of nuclei into two composite nuclear fragments. The nuclear interaction potentials required to describe these nuclear decay processes have been calculated by double folding the density distribution functions of the two fragments with a realistic effective interaction. The microscopic nucleus-nucleus potential thus obtained, along with the Coulomb interaction potential and the minimum centrifugal barrier required for the spin-parity conservation, has been used successfully for the lifetime calculations of these nuclear disintegration processes.

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arXiv2002

Potential turning points in cluster radioactivity

Effects of various nuclear interaction potentials on the decay lifetimes and the turning points of the WKB action integral has been studied. The microscopic nuclear potential obtained by folding in the density distribution functions of the two clusters with a realistic effective interaction has also been used to calculate the turning points. Half lives of alpha and ^{20}O cluster emissions from ^{228}Th have been calculated within the superasymmetric fission model using various phenomenological and the microscopic double folding potentials. Calculations of half lives with the microscopic double folding potentials are found to be in good agreement with the observed experimental data. Present calculations put the superasymmetric fission model on a firm theoretical basis.

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arXiv2002

Dissipative collisions in $^{16}$O + $^{27}$Al at E$_{lab}$=116 MeV

The inclusive energy distributions of fragments (3$\leq$Z$\leq$7) emitted in the reaction $^{16}$O + $^{27}$Al at $E_{lab} = $116 MeV have been measured in the angular range $θ_{lab} $= 15$^\circ$ - 115$^\circ$. A non-linear optimisation procedure using multiple Gaussian distribution functions has been proposed to extract the fusion-fission and deep inelastic components of the fragment emission from the experimental data. The angular distributions of the fragments, thus obtained, from the deep inelastic component are found to fall off faster than those from the fusion-fission component, indicating shorter life times of the emitting di-nuclear systems. The life times of the intermediate di-nuclear configurations have been estimated using a diffractive Regge-pole model. The life times thus extracted ($\sim 1 - 5\times 10^{-22}$ Sec.) are found to decrease with the increase in the fragment charge. Optimum Q-values are also found to increase with increasing charge transfer i.e. with the decrease in fragment charge.

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arXiv2002

Spontaneous heavy cluster emission rates using microscopic potentials

The nuclear cluster radioactivities have been studied theoretically in the framework of a microscopic superasymmetric fission model (MSAFM). The nuclear interaction potentials required for binary cold fission processes are calculated by folding in the density distribution functions of the two fragments with a realistic effective interaction. The microscopic nuclear potential thus obtained has been used to calculate the action integral within the WKB approximation. The calculated half lives of the present MSAFM calculations are found to be in good agreement over a wide range of observed experimental data.

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arXiv2002

A microscopic description for the alpha decay of nuclei using a realistic effective interaction

The process of alpha disintegration has been studied theoretically in the framework of a microscopic superasymmetric fission model (MSAFM). The nuclear interaction potential required for the alpha decay process has been calculated by folding in the density distribution functions of the alpha nucleus and the daughter nucleus with a realistic effective interaction. The nuclear microscopic alpha-nucleus potential thus obtained has been used along with the Coulomb interaction potential to calculate the action integral within the WKB approximation. This subsequently results in a parameter free calculation for the half lives of the alpha decays of nuclei. The model is successful in calculating the half lives of the alpha disintegration processes of nuclei.

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arXiv1999

Saturation of product's exoticity in compound nuclear reactions and its role in the production of new n-deficient nuclei with radioactive projectiles

Representation in terms of a new parameter, exoticity, a measure of n-deficiency or p-richness, clearly brings out the saturation tendency of the product's maximum exoticity in a compound nuclear reaction as the compound nucleus is made more and more exotic using radioactive projectile (RIBs). The effect of this saturation on the production of new proton-rich species with RIBs over a wide Z-range has been discussed.

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arXiv1996

Spin polarised nuclear matter and its application to neutron stars

An equation of state(EOS) of nuclear matter with explicit inclusion of a spin-isospin dependent force is constructed from a finite range, momentum and density dependent effective interaction. This EOS is found to be in good agreement with those obtained from more sophisticated models for unpolarised nuclear matter. Introducing spin degrees of freedom, it is found that at density about 2.5 times the density of normal nuclear matter the neutron matter undergoes a ferromagnetic transition. The maximum mass and the radius of the neutron star agree favourably with the observations. Since finding quark matter rather than spin polarised nuclear matter at the core of neutron stars is more probable, the proposed EOS is also applied to the study of hybrid stars. It is found using the bag model picture that one can in principle describe both the mass and size as well as the surface magnetic field of hybrid stars satisfactorily.

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