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Related papers: Microscopic study of Ca$+$Ca fusion

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The barrier distribution, originated from channel coupling effects in heavy-ion fusion reactions, has been extracted experimentally for many systems using either a fusion excitation function or an excitation function of large-angle…

Nuclear Theory · Physics 2019-10-02 K. Hagino , T. Tanaka

In the search for superheavy elements quasifission reactions represent one of the reaction pathways that curtail the formation of an evaporation residue. In addition to its importance in these searches quasifission is also an interesting…

Nuclear Theory · Physics 2020-03-23 K. Godbey , A. S. Umar

Recent experiments revealed intriguing similarities in the $^{64}$Ni+$^{207}$Pb, $^{132}$Xe+$^{208}$Pb, and $^{238}$U+$^{238}$U reactions at energies around the Coulomb barrier. The experimental data indicate that for all systems…

Nuclear Theory · Physics 2017-03-01 Kazuyuki Sekizawa , Sophia Heinz

These lecture notes are addressed to PhD student and/or researchers who want a general overview of microscopic approaches based on mean-field and applied to nuclear dynamics. Our goal is to provide a good description of low energy heavy-ion…

Nuclear Theory · Physics 2009-04-20 Cédric Simenel , Benoît Avez , Denis Lacroix

Background: At energies near the Coulomb barrier, capture reactions in heavy-ion collisions result either in fusion or in quasifission. The former produces a compound nucleus in statistical equilibrium, while the second leads to a…

Nuclear Theory · Physics 2016-05-12 A. S. Umar , V. E. Oberacker , C. Simenel

We introduce a microscopic approach for calculating the excitation energies of systems formed during heavy-ion collisions. The method is based on time-dependent Hartree-Fock (TDHF) theory and allows the study of the excitation energy as a…

Nuclear Theory · Physics 2009-10-29 A. S. Umar , V. E. Oberacker , J. A. Maruhn , P. -G. Reinhard

Recent advances obtained in the field of near and sub-barrier heavy-ion fusion reactions are reviewed. Emphasis is given to the results obtained in the last decade, and focus will be mainly on the experimental work performed concerning the…

Nuclear Experiment · Physics 2017-09-13 Giovanna Montagnoli , Alberto M. Stefanini

Quasi-fission is the primary reaction mechanism that prevents the formation of superheavy elements in heavy-ion fusion experiments. Employing the time-dependent density functional theory approach we study quasi-fission in the systems…

Nuclear Theory · Physics 2014-11-11 V. E. Oberacker , A. S. Umar , C. Simenel

We motivate and summarise some recent results in the application of formally exact boundary conditions in nuclear time-dependent Hartree-Fock calculations, making use of Laplace transformations to calculate the values of the wave functions…

Nuclear Theory · Physics 2013-05-30 P. D. Stevenson , C. I. Pardi

The two-step model for fusion reactions of massive systems is briefly reviewed.By the use of fusion probabilities obtained by the model and of survival probabilities obtained by the new statistical code, we predict residue cross sections…

Nuclear Theory · Physics 2009-11-10 Yasuhisa Abe , Bertrand Bouriquet , Caiwan Shen , Grigori Kosenko

We employ the time-dependent Hartree-Fock (TDHF) method to study various aspects of the reactions utilized in searches for superheavy elements. These include capture cross-sections, quasifission, prediction of $P_{\mathrm{CN}}$, and other…

Nuclear Theory · Physics 2016-04-12 A. S. Umar , V. E. Oberacker

An analysis of the asymmetric reactions $^{40,48}$Ca+$^{12}$C at 25 and 40 MeV/nucleon is presented. Data have been collected with six modules of the FAZIA array. The analysis is focused on the breakup channel of sources produced in…

Couplings between relative motion and internal structures are known to affect fusion barriers by dynamically modifying the densities of the colliding nuclei. The effect is expected to be stronger at energies near the barrier top, where…

Nuclear Theory · Physics 2014-03-13 A. S. Umar , C. Simenel , V. E. Oberacker

Microscopic methods and tools to describe nuclear dynamics have considerably been improved in the past few years. They are based on the time-dependent Hartree-Fock (TDHF) theory and its extensions to include pairing correlations and quantum…

Nuclear Theory · Physics 2018-09-13 C. Simenel , A. S. Umar

Background: Nuclear fission is a complex large-amplitude collective decay mode in heavy nuclei. Microscopic density functional studies of fission have previously concentrated on adiabatic approaches based on constrained static calculations…

Nuclear Theory · Physics 2015-11-18 P. M. Goddard , P. D. Stevenson , A. Rios

We analyze the details of mass exchange in the vicinity of the Coulomb barrier for heavy-ion collisions involving neutron-rich nuclei using the time-dependent Hartree-Fock (TDHF) theory. We discuss the time-dependence of transfer and show…

Nuclear Theory · Physics 2008-11-26 A. S. Umar , V. E. Oberacker , J. A. Maruhn

The fusion process of $^{48}$Ca induced reactions is studied with the two-step model. In this model, the fusion process is devided into two stages: first, the sticking stage where projectile and target come to the touching point over the…

Nuclear Theory · Physics 2011-07-28 Caiwan Shen , Yasuhisa Abe , Davoid Boilley , Grigory Kosenko , Enguang Zhao

The influence on the fusion process of coupling to collective degrees of freedom has been explored. The significant enhancement of the fusion cross section at sub-barrier energies was compared to predictions of one-dimensional barrier…

Nuclear Theory · Physics 2008-11-26 C. Beck

The fusion hindrance, which is also denominated by the term extra-push, is studied on mass-symmetric systems by the use of the liquid drop model with the two-center parameterization. Following the idea that the fusion hindrance exists only…

Nuclear Theory · Physics 2009-09-25 Caiwan Shen , Yasuhisa Abe , Qingfeng Li , David Boilley

We study dissipation and relaxation processes within the time-dependent Hartree-Fock approach using the Wigner distribution function. On the technical side we present a geometrically unrestricted framework which allows us to calculate the…

Nuclear Theory · Physics 2012-08-30 N. Loebl , A. S. Umar , J. A. Maruhn , P. -G. Reinhard , P. D. Stevenson , V. E. Oberacker