Strong influence of the entrance channel on the formation of compound nuclei<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mmultiscripts><mml:mi mathvariant="normal">Th</mml:mi><mml:mprescripts /><mml:none /><mml:mrow><mml:mn>216</mml:mn><mml:mo>,</mml:mo><mml:mn>222</mml:mn></mml:mrow></mml:mmultiscripts><mml:msup><mml:mi /><mml:mrow><mml:mo>*</mml:mo></mml:mrow></mml:msup></mml:math>and their evaporation residues

Fazio, G.; Giardina, G.; Mandaglio, G.; Ruggeri, R.; Muminov, A. I.; Nasirov, A. K.; Oganessian, Yu. Ts.; Popeko, A. G.; Sagaidak, R. N.; Yeremin, A. V.; Hofmann, S.; Hanappe, F.; Stödel, C.

doi:10.1103/physrevc.72.064614

Cited by 70 publications

(92 citation statements)

References 54 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…[6,7,13 Hereafter, the CN excitation energy E * CN is used instead of the collision energy in the center-of-mass system E c.m. for the convenience of comparison of the reactions having large difference in the Coulomb barrier energies.…”

Section: Resultsmentioning

confidence: 99%

“…[1][2][3][4][5][6][7]). In all of these works, the results of the comparison led to the same conclusions: the evaporation residue(ER) cross sections of the same heated and rotating CN are different even at the same value of the excitation energy E * CN .…”

Section: Introductionmentioning

confidence: 99%

“…The extent of the hindrance is determined by the peculiarities of the potential energy surface [refs. [3][4][5][6][7] which contains shell effects of the intrinsic structure of interacting nuclei that change nature during the lifetime and evolution of the dinuclear system(DNS) formed at capture of the projectile by the target. The hindrance to complete fusion is related with the increase of the quasifission events (decay of DNS into two fragments) which are in competition with the complete fusion events.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Real causes of apparent abnormal results in heavy ion reactions

Mandaglio

Nasirov

Anastasi

et al. 2015

EPJ Web of Conferences

Self Cite

View full text Add to dashboard Cite

Abstract. We study the effect of the static characteristics of nuclei and dynamics of the nucleus-nucleus interaction in the capture stage of reaction, in the competition between quasifission and complete fusion processes, as well as the angular momentum dependence of the competition between fission and evaporation processes along the de-excitation cascade of the compound nucleus. The results calculated for the mass-asymmetric and less mass-asymmetric reactions in the entrance channel are analyzed in order to investigate the role of the dynamical effects on the yields of the evaporation residue nuclei. We also discuss about uncertainties at the extraction of such relevant physical quantities as Γ n /Γ tot ratio or also excitation functions from the experimental results due to the not always realistic assumptions in the treatment and analysis of the detected events. This procedure can lead to large ambiguity when the complete fusion process is strongly hindered or when the fast fission contribution is large. We emphasize that a refined multiparameter model of the reaction dynamics as well as a more detailed and checked data analysis are strongly needed in heavy-ion collisions.

show abstract

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Real causes of apparent abnormal results in heavy ion reactions

Mandaglio

Nasirov

Anastasi

et al. 2015

EPJ Web of Conferences

Self Cite

View full text Add to dashboard Cite

show abstract

“…Most dynamical models [13][14][15][16][17][18][19] argue that, for heavy systems, a dinuclear complex is formed initially and the barrier structure and the excitation energy of this precompound system determine its survival to breaking up via quasi-fission. Furthermore, if the nucleus survives this initial state and evolves to a compound system, it can still fission due to its excitation.…”

Section: Introductionmentioning

confidence: 99%

Shape evolution and collective dynamics of quasifission in the time-dependent Hartree-Fock approach

2015

View full text Add to dashboard Cite

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 reseparation of the fragments after partial mass equilibration without formation of a compound nucleus. Extracting the compound nucleus formation probability is crucial to predict superheavy-element formation crosssections. It requires a good knowledge of the fragment angular distribution which itself depends on quantities such as moments of inertia and excitation energies which have so far been somewhat arbitrary for the quasifission contribution.Purpose: Our main goal is to utlize the time-dependent Hartee-Fock (TDHF) approach to extract ingredients of the formula used in the analysis of experimental angular distributions. These include the moment-of-inertia and temperature.Methods: We investigate the evolution of the nuclear density in TDHF calculations leading to quasifission. We study the dependence of the relevant quantities on various initial conditions of the reaction process.Results: The evolution of the moment of inertia is clearly non-trivial and depends strongly on the characteristics of the collision. The temperature rises quickly when the kinetic energy is transformed into internal excitation. Then, it rises slowly during mass transfer.Conclusions: Fully microscopic theories are useful to predict the complex evolution of quantities required in macroscopic models of quasifission.

show abstract

“…What is also difficult to ascertain is the configuration of the composite system, namely, whether the system has a single-center compound-like configuration or a dinuclear configuration accompanied by particle exchange. Most dynamical models [7][8][9][10][11] argue that for heavy systems a dinuclear complex is formed initially and the barrier structure and the excitation energy of this precompound system will determine its survival to breaking up via quasifission. Furthermore, if the nucleus survives this initial state and evolves to a compound system it can still fission due to its excitation.…”

Section: Introductionmentioning

confidence: 99%

Quasifission dynamics in TDHF

Umar

Oberacker

Simenel

2016

EPJ Web of Conferences

View full text Add to dashboard Cite

For light and medium mass systems the capture cross-section may be considered to be the same as that for complete fusion, whereas for heavy systems leading to superheavy formations the evaporation residue cross-section is dramatically reduced due to the quasifission (QF) and fusion-fission processes thus making the capture cross-section to be essentially the sum of these two cross-sections, with QF occurring at a much shorter time-scale. Consequently, quasifission is the primary reaction mechanism that limits the formation of superheavy nuclei. Within the last few years the time-dependent Hartree-Fock (TDHF) approach has been utilized for studying the dynamics of quasifission. The study of quasifission is showing a great promise to provide insight based on very favorable comparisons with experimental data. In this article we will focus on the TDHF calculations of quasifission observables for the 48 Ca+ 249 Bk system.

show abstract

Strong influence of the entrance channel on the formation of compound nucleiTh216,222*and their evaporation residues

Cited by 70 publications

References 54 publications

Real causes of apparent abnormal results in heavy ion reactions

Real causes of apparent abnormal results in heavy ion reactions

Shape evolution and collective dynamics of quasifission in the time-dependent Hartree-Fock approach

Quasifission dynamics in TDHF

Contact Info

Product

Resources

About