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Adel, A., V. A. Rachkov, A. V. Karpov, A. S. Denikin, M. Ismail, W. M. Seif, and A. Y. Ellithi, "Effect of neutron rearrangement on subbarrier fusion reactions", Nuclear Physics A, vol. 876, pp. 119-130, 2012. AbstractWebsite

The role of neutron transfer is investigated in the fusion process near and below the Coulomb barrier within the empirical channel coupling approach. The possibility of neutron transfer with positive Q-values considerably increases the barrier penetrability. The enhancement of fusion cross sections for 58Ni+ 64Ni, 32S+ 64Ni, 40Ca+ 48Ca, and 40Ca+ 124Sn is well reproduced at subbarrier energies by the empirical channel coupling approach including the coupling to the neutron-transfer channels. The predictions of the fusion cross sections for several combinations of colliding nuclei are also proposed which may shed additional light on the effect of neutron transfer in fusion processes. A huge enhancement of deep subbarrier fusion probability was found for light neutron-rich weakly bound nuclei. This may be quite important for astrophysical primordial and supernova nucleosynthesis. © 2012 Elsevier B.V..

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El Shabshiry, M., A. Faessler, and M. Ismail, "Effects of the Pauli blocking and surface contribution to the optical potential on the ion-ion reaction cross section", Journal of Physics G: Nuclear and Particle Physics, vol. 15, no. 4, pp. L59-L62, 1989. AbstractWebsite

The energy dependence of the ion-ion reaction cross section has been investigated using the eikonal approximation to study the effects of the Pauli blocking and surface contribution to the optical potential. This leads to theoretical cross sections lower than the data. If the collective surface contribution is added to the volume part, one obtains reasonable agreement with experiment at higher energies.

Elmahdy, N. A., A. S. Denikin, M. Ismail, and A. Y. Ellithi, "6Li breakup and suppression of complete fusion above the Coulomb barrier", European Physical Journal A, vol. 51, pp. 62, 2015. Abstract

We study the role of the projectile breakup in the fusion process by example of the 6Li reactions with the 59Co, 144Sm and 209Bi targets in vicinity of the Coulomb barrier. The coupled channel and distorted wave approaches are employed in order to calculate the complete fusion and the breakup cross sections, respectively. The partial cross sections in both the channels are compared in order to estimate the breakup fraction responsible for the suppression of complete fusion. The calculations are compared with available experimental data. The conclusions and recommendations are made.

F
Faessler, A. a, and M. b Ismail, "The volume contribution of the ion-ion optical potential from realistic complex nucleon-nucleon interaction", Zeitschrift für Physik A Atoms and Nuclei, vol. 316, no. 2, pp. 195-199, 1984. AbstractWebsite

The real and imaginary parts of the optical model potential for several pairs of magic nuclei have been calculated by a double folding procedure. The complex effective interaction is calculated from the Reid soft core potential by solving the Bethe-Goldstone equation in two colliding nuclear matters. The calculated potentials were approximated with a Woods-Saxon shape. We studied the dependence of the parameters of these Woods-Saxon forms on the masses of the interacting nuclei. © 1984 Springer-Verlag.

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Ismail, M., A. Y. Ellithi, M. M. Botros, and A. Adel, "Systematics of α-decay half-lives around shell closures", Physical Review C - Nuclear Physics, vol. 81, no. 2, 2010. AbstractWebsite

{We present a systematic calculation of α-decay half-lives of even-even heavy and superheavy nuclei in the framework of the preformed α model. The microscopic α-daughter nuclear interaction potential is calculated by double-folding the density distributions of both α and daughter nuclei with a realistic effective Michigan three-Yukawa nucleon-nucleon interaction, and the microscopic Coulomb potential is calculated by folding the charge density distributions of the two interacting nuclei. The half-lives are found to be sensitive to the density dependence of the nucleon-nucleon interaction and the implementation of the Bohr-Sommerfeld quantization condition inherent in the Wentzel-Kramers-Brillouin approach. The α-decay half-lives obtained agree reasonably well with the available experimental data. Moreover, the study has been extended to the newly observed superheavy nuclei. The interplay of closed-shell effects in α-decay calculations is investigated. The α-decay calculations give the closed-shell effects of known spherical magicities

Ismail, M., M. M. Botros, and A. A. Wheida, "Accuracy of the multipole expansion of density distribution in the presence of octupole deformation", International Journal of Modern Physics E, vol. 20, no. 12, pp. 2407-2415, 2011. AbstractWebsite

The accuracy of multipole expansion of density distribution for deformed nuclei is tested. The interaction potential for a deformed-spherical pair of nuclei was calculated using the folding model derived from zero-range nucleonnucleon (NN) interaction. We considered two spherical projectiles Ca 40 and Pb 208 scattered on U 238 deformed target nucleus. The error in the heavy ion (HI) potential resulting from using a truncated multipole density expansion is evaluated for each case in the presence of octupole deformation δ 3 besides quadrupole δ 2. We are interested in the value of error for R < R T (touching distance). We found that for values of |δ 3|≤0.1 the error at R = R T reaches reasonable values when six terms expansion is used. For |δ 3| = 0.2, we calculated the Coulomb barrier parameters using realistic NN force and found that the large error present in six terms for zero range force decreases strongly to less than 1% when the zero range is added to finite range forces and Coulomb interaction to form the Coulomb barrier. It is noted that the negative value of octupole deformation parameters δ 3 = -0.1 produce error at orientation angle θ equal in value to that produced at angle (180°-θ) for the positive values δ 3 = 0.1. We also found that the error decreases as the mass number of the projectile nucleus increases. © 2011 World Scientific Publishing Company.

Ismail, M., and K. Ramadan, "Improving the calculation of the potential between spherical and deformed nuclei", Acta Physica Polonica B, vol. 8, pp. 1783, 2000.
Ismail, M., W. M. Seif, A. S. Hashem, M. M. Botros, and I. A. M. Abdul-Magead, "Ternary fission of 260No in collinear configuration", Annals of Physics, vol. 372, pp. 375-391, 2016. AbstractWebsite
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Ismail, M., and A. Adel, "Orientation dependent behavior of the Coulomb barrier parameters for deformed-deformed nuclei", Nuclear Physics A, vol. 859, no. 1, pp. 1-15, 2011. AbstractWebsite

The Coulomb barrier parameters (radius, Rb, and height, Vb) for the interaction between two deformed nuclei are calculated in phenomenological way in the framework of the double folding model with the realistic M3Y nucleon-nucleon (NN) interaction. The variations of Rb and Vb for the reactions Ar48+Pu238, Mg26+Cm248, Mg26+U238, and Ne22+U238 in the orientation degrees of freedom are investigated. It is found that the distribution of the Coulomb barrier parameters in the orientation degrees of freedom shows almost the same patterns as the sum of the nuclear radii of the interacting nuclei along the direction of the separation vector joining their two centers of mass. The orientation Coulomb barrier radius distribution follows the same variations as the sum of radii while the barrier height distribution follows it inversely. This correlation (anticorrelation) between Rb (Vb) and the nuclear radii of the deformed nuclei dose not give the values of Rb and Vb. This suggests a simple and straightforward way to predict the behavior of the barrier parameters with different orders of deformations without performing the heavy numerical calculations necessary when the two nuclei are being deformed. It also allows us to estimate, with reasonable accuracy, the compact and elongated configurations of the interacting nuclei which lead to hot and cold fusion reactions, respectively. © 2011 Elsevier B.V.

Ismail, M., A. Y. Ellithi, H. El-Gebaly, and A. A. Mohamed, "STUDY OF SOME ASPECTS OF REACTION CROSS-SECTION BETWEEN DEFORMED NUCLEI", International Journal of Physics and Research (IJPR), vol. 3, issue 5, pp. 1-10, 2013.
Ismail, M., A. Y. Ellithi, A. Adel, and H. Anwer, "Islands of stability and quasi-magic numbers for super- and ultra-heavy nuclei", Chinese Physics C, vol. 40, no. 12, 2016. AbstractWebsite
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Ismail, M., and I. A. M. Abdul-Magead, "Comparison between different proximity potentials and the double-folding model for spherical–deformed interacting nuclei", Canadian Journal of Physics, vol. 94, no. 1, pp. 102-111, 2016. AbstractWebsite
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Ismail, M., and A. Adel, "Shell corrections for heavy and superheavy nuclei", International Journal of Modern Physics E, vol. 21, no. 6, 2012. AbstractWebsite

{The shell and pairing correction energies are calculated for heavy and superheavy nuclei (SHN) by means of the Strutinsky's method. The single-particle (s.p.) energy levels are obtained from the diagonalization of the WoodsSaxon s.p. Hamiltonian in the deformed harmonic oscillator basis for both neutrons and protons. The residual pairing interaction is calculated by means of the usual BardeenCooperSchrieffer (BCS) approximation. A two-dimensional deformation space describing axially and reflection-symmetric shapes of nuclei has been used. Based on the shell and pairing correction energies, the signatures of the magic numbers appear at the spherical shell closures Z = 82, 114, 164 and N = 126, 184, 228 and 308. There are also signatures for some other shell closures at, e.g.

Ismail, M., and A. Y. Ellithi, "The effect of nuclear matter compressibility on fusion cross-section and barrier distribution of deformed-spherical nuclei", Chaos, Solitons and Fractals, vol. 14, no. 9, pp. 1425-1431, 2002. AbstractWebsite

A method has been advised to calculate the interaction potential between deformed-spherical nuclear pair using density dependent nucleon-nucleon (NN) effective interaction. We performed our study on 16O- 238U nuclear pair using four types of recently derived density dependent NN forces. These forces correspond to different values of nuclear matter compressibility coefficient (K). The orientation and density dependence on the heavy ion potential is studied at different nuclear matter compressibility. The fusion cross-section and the fusion barrier distribution have been calculated for the pair considered. We found that density dependence affects the fusion cross-section and the barrier distribution at low values of compressibility and no effect for high compressibility case. © 2002 Elsevier Science Ltd. All rights reserved.

Ismail, M., A. Faessler, and M. Trefz, "Test of proximity theorem for the nucleus-nucleus potential derived from a realistic NN force", Journal of Physics G: Nuclear Physics, vol. 12, no. 7, pp. L157-L159, 1986. AbstractWebsite

The authors investigate the proximity scaling for the nuclear part of the nucleus-nucleus potential derived from the collision of two infinite nuclear matters flowing through each other. It is found that the proximity theorem is satisfied to a good extent at each value of the projectile energy per nucleon. They simplify the interaction potential between different pairs of nuclei by the product of a geometrical factor, dependent on the radii of the interacting nuclei, and a gaussian distribution whose parameters depend on the projectile energy per nucleon.

Ismail, M., and A. Adel, "Prediction of nuclear spin based on the behavior of α-particle preformation probability", Physical Review C, vol. 88, pp. 054604, 2013.
Ismail, M., and A. Adel, "Investigation of possible correlation between α -particle preformation probability and energy levels for α emitters with 74≤Z≤83", Physical Review C, vol. 90, pp. 064624, 2014. Abstract

The preformation probability of an α cluster inside radioactive parent nuclei is investigated. The calculations are employed in the framework of the density-dependent cluster model for both even-even and odd-A isotopes with 74≤Z≤83 . A realistic density-dependent nucleon-nucleon (NN ) interaction with a finite-range exchange part is used to calculate the microscopic α -nucleus potential in the well-established double-folding model. The main effect of antisymmetrization under exchange of nucleons between the α and daughter nuclei has been included in the folding model through the finite-range exchange part of the NN interaction. The calculated potential is then implemented to find both the assault frequency and the penetration probability of the α particle by means of the Wentzel-Kramers-Brillouin approximation in combination with the Bohr-Sommerfeld quantization condition. We investigated the correlation between the α -particle preformation probability, S α , and the energy levels of the parent nucleus for α emitters with atomic number 74≤Z≤83 . Based on the similarity in the behavior of S α with the neutron number for two nuclei, we try to predict or confirm the unknown or doubted nuclear spins and parities in this mass region.

Ismail, M., A. Y. Ellithi, A. Adel, and H. Anwer, "On magic numbers for super-and ultraheavy systems and hypothetical spherical double-magic nuclei", Journal of Physics G: Nuclear and Particle Physics, vol. 43, no. 1: IOP Publishing, pp. 015101, 2015. Abstract
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Ismail, M. Y., A. Y. Ellithi, M. M. Osman, and M. M. Botros, "The Deformation and Orientation Effect on Reaction Cross Section with Deformed Targets", Physics of Atomic Nuclei, vol. 66, no. 9, pp. 1607-1614, 2003. AbstractWebsite

The reaction cross section (σ R) for a deformed target nucleus and spherical projectile is calculated using the optical-limit approximation of the Glauber-Sitenko theory. A method is presented to include both the density-dependent N N interaction and the higher order deformations of the target nucleus in the collision process. We studied both the orientation and the deformation dependence of σ R within the energy range 30-900 MeV/A We found that the orientation of the heavy target nucleus (A ≥ 120) can produce a difference in the calculated σ R up to 30%. The averaged σ R over all directions of the symmetry axis of the deformed nucleus differs by less than 1 % compared with σ R calculated for a spherical target with the same rms matter radius as the deformed nucleus. For certain orientation, it was found that σ R is highly dependent on the hexadecapole deformation. The orientation-averaged cross sections show almost no variation with either the sign or the value of the hexadecapole deformation. We compared the average cross section with the experimental data for several mass numbers; fair agreement is obtained. © 2003 MAIK "Nauka/Interperiodica".

Ismail, M., W. M. Seif, H. Abou-Shady, and A. Bakry, "Study of Coulomb interaction for two diffuse spherical-deformed nuclei", Physics of Atomic Nuclei, vol. 69, no. 9, pp. 1463-1471, 2006. AbstractWebsite

The Coulomb interaction for a spherical-deformed interacting pair is derived assuming realistic nuclear charge distributions. The effect of a finite diffuseness parameter is described either by the folding product of spherical or deformed sharp-surface distribution and a spherical short-range function or by using a Fermi two-parameter distribution function. The approximate solutions obtained using these categories of charge distributions are then compared to the numerical solution obtained within the framework of the double-folding model. We found that the finite surface diffuseness parameter affects slightly the inner region of the total Coulomb potential, while it produces large errors in calculating the Coulomb form factors used frequently in nuclear reactions and fusion numerical codes. © Nauka/Interperiodica 2006.

Ismail, M., "TWO-NUCLEON STRIPPING PROCESS WITH EFFECTIVE INTERACTIONS.", J Phys (Paris), vol. 38, no. 8, pp. 897-903, 1977. AbstractWebsite

The form factor of the two-nucleon stripping process **4**0Ca(t,p)**4**2Ca is studied using two types of effective interactions, namely the Skyrme and Brink-Boeker interactions. The results are compared with those of the ordinary zero-range potential. It is found that the effective interactions reduce the importance of the nuclear internal region. In addition the form factors calculated with effective interactions differ from the zero-range form factor in both the surface and asymptotic regions.

Ismail, M., F. Salah, and M. M. Osman, "Accuracy of calculating the real alpha- nucleus potential", Physical Review C, vol. 54, pp. 3308, 1996.
Ismail, M., and A. Adel, "Effect of energy level sequences and neutron–proton interaction on $\alpha$-particle preformation probability", Nuclear Physics A, vol. 912: North-Holland, pp. 18–30, 2013. Abstract
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