Production probability of superheavy fragments at various initial deformations and orientations in the<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:msup><mml:mrow /><mml:mn>238</mml:mn></mml:msup></mml:math>U<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:msup><mml:mo>+</mml:mo><mml:mn>238</mml:mn></mml:msup></mml:math>U reaction

Zhao, Kai; Li, Zhuxia; Wu, X.; Zhang, Yingxun

doi:10.1103/physrevc.88.044605

Cited by 33 publications

(15 citation statements)

References 29 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The GRAZING has recently been extended to incorporate transfer-induced fission, which is referred to as GRAZING-F [26]. To describe damped collisions, a dynamical model based on Langevin-type equations [9][10][11][12][13][27][28][29][30], the dinuclear system (DNS) model [14][15][16][17][31][32][33][34][35][36][37][38], and the improved quantum molecular dynamics model (ImQMD) [39][40][41][42][43][44] have been extensively developed. Despite numerous successes in describing measurements, they are to some extent empirical, containing adjustable parameters.…”

Section: Introductionmentioning

confidence: 99%

Time-dependent Hartree-Fock calculations for multinucleon transfer and quasifission processes in theNi64+U238reaction

2016

View full text Add to dashboard Cite

Background: Multinucleon transfer (MNT) and quasifission (QF) processes are dominant processes in lowenergy collisions of two heavy nuclei. They are expected to be useful to produce neutron-rich unstable nuclei. Nuclear dynamics leading to these processes depends sensitively on nuclear properties such as deformation and shell structure.Purpose: We elucidate reaction mechanisms of MNT and QF processes involving heavy deformed nuclei, making detailed comparisons between microscopic time-dependent Hartree-Fock (TDHF) calculations and measurements for the 64 Ni+ 238 U reaction.Methods: Three-dimensional Skyrme-TDHF calculations are performed. Particle-number projection method is used to evaluate MNT cross sections from the TDHF wave function after collision.Results: Fragment masses, total kinetic energy (TKE), scattering angle, contact time, and MNT cross sections are investigated for the 64 Ni+ 238 U reaction. They show reasonable agreements with measurements. At small impact parameters, collision dynamics depends sensitively on the orientation of deformed 238 U. In tip (side) collisions, we find a larger (smaller) TKE and a shorter (longer) contact time. In tip collisions, we find a strong influence of quantum shells around 208 Pb.Conclusions: It is confirmed that the TDHF calculations reasonably describe both MNT and QF processes in the 64 Ni+ 238 U reaction. Analyses of this system indicate the significance of the nuclear structure effects such as deformation and quantum shells in nuclear reaction dynamics at low energies.

show abstract

Section: Introductionmentioning

confidence: 99%

Time-dependent Hartree-Fock calculations for multinucleon transfer and quasifission processes in theNi64+U238reaction

2016

View full text Add to dashboard Cite

show abstract

“…Recently, this problem has been also investigated in Refs. [21,22] within the improved quantum molecular dynamics model as well as in Ref. [23] within the dinuclear system model.…”

mentioning

confidence: 99%

Analysis of multinucleon transfer reactions with spherical and statically deformed nuclei using a Langevin-type approach

Saiko

Карпов

2019

Phys. Rev. C

View full text Add to dashboard Cite

Background: An increasing interest in multinucleon transfer processes in low-energy deep inelastic (damped) collisions of heavy ions appeared in recent years is due, in part, to by the possibility of using them as a method of production of heavy neutron-enriched nuclei. Possible promising projectile-target combinations include nuclei deformed in the ground state (e.g., actinides). Mutual orientations of such the nuclei in the entrance channel of the reaction may significantly influence the reaction dynamics.Purpose: A major aim of the work is to implement a possibility of modeling collisions of statically deformed heavy nuclei within a multidimensional dynamical model based on the Langevin equations. Another purpose of the paper is to study the influence of mutual orientation of statically deformed nuclei on their collision dynamics. Finally, the production yields of heavy transuranium nuclei in collisions of actinides are examined.Method: The analysis has been performed within multidimensional dynamical model of nucleus-nucleus collisions based on the Langevin equations [Phys. Rev. C 96 024618 (2017)]. In the present paper the model has been improved to describe collisions of statically deformed heavy nuclei with different mutual orientations.Results: Available experimental data on multinucleon transfer reactions with statically deformed as well as spherical heavy nuclei 144 Sm + 144 Sm, 154 Sm + 154 Sm, 160 Gd + 186 W, and 208 Pb + 208 Pb/ 238 U have been analyzed within the developed model. A good agreement of the calculated quantities with the corresponding experimental data is reached. Special attention in the paper is paid to analysis of production possibility of the neutron-enriched isotopes of heavy and superheavy elements in multinucleon transfer processes in the 238 U + 238 U/ 248 Cm/ 254 Es collisions. Conclusions:The mutual orientation of colliding statically deformed nuclei in the entrance channel strongly affects the energy, angular, mass, and charge characteristics of multinucleon transfer reaction products at nearbarrier energies. These orientational effects disappear with increasing collision energy well above the Coulomb barrier. The exponential drop of the isotopic distributions of above-target products formed in the collisions of actinides with increasing atomic number does not allow one to synthesize new isotopes of superheavy nuclei with experimentally reachable cross sections. However, there is a possibility of production of a number of neutronenriched isotopes of heavy actinides with the cross sections exceeding 1 µb.

show abstract

“…On the other hand, different theoretical approaches have also been developed: e.g. a dynamical model based on Langevin-type equations of motion [5][6][7][8][9][10][11][12], dinuclear system model (DNS) [13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28], and improved quantum molecular dynamics model (ImQMD) [29][30][31][32][33][34][35][36][37][38]. Although those models can describe both peripheral and damped collisions, including fusion and quasifission (QF) processes, they are to some extent empirical containing model parameters.…”

Section: Introductionmentioning

confidence: 99%

Microscopic description of production cross sections including deexcitation effects

Sekizawa

2017

Phys. Rev. C

View full text Add to dashboard Cite

Background: At the forefront of the nuclear science, production of new neutron-rich isotopes is continuously pursued at accelerator laboratories all over the world. To explore the currently-unknown territories in the nuclear chart far away from the stability, reliable theoretical predictions are inevitable.Purpose: To provide a reliable prediction of production cross sections taking into account secondary deexcitation processes, both particle evaporation and fission, a new method called TDHF+GEMINI is proposed, which combines the microscopic time-dependent Hartree-Fock (TDHF) theory with a sophisticated statistical compoundnucleus deexcitation model, GEMINI++.Methods: Low-energy heavy ion reactions are described based on three-dimensional Skyrme-TDHF calculations. Using particle-number projection method, production probabilities, total angular momenta, and excitation energies of primary reaction products are extracted from the TDHF wavefunction after collision. Production cross sections for secondary reaction products are evaluated employing GEMINI++. Results are compared with available experimental data and widely-used GRAZING calculations. Results:The method is applied to describe cross sections for multinucleon transfer processes in MeV) reactions at energies close to the Coulomb barrier. It is shown that the inclusion of secondary deexcitation processes, which are dominated by neutron evaporation in the present systems, substantially improves agreement with the experimental data. The magnitude of the evaporation effects is very similar to the one observed in GRAZING calculations. TDHF+GEMINI provides better description of the absolute value of the cross sections for channels involving transfer of more than one protons, compared to the GRAZING results. However, there remain discrepancies between the measurements and the calculated cross sections, indicating a limit of the theoretical framework that works with a single mean-field potential. Possible causes of the discrepancies are discussed. Conclusions:In order to perfectly reproduce experimental cross sections for multinucleon transfer processes, one should go beyond the standard self-consistent mean-field description. Nevertheless, the proposed method will provide valuable information to optimize production mechanisms of new neutron-rich nuclei through its microscopic, non-empirical predictions.

show abstract

Production probability of superheavy fragments at various initial deformations and orientations in the238U+238U reaction

Cited by 33 publications

References 29 publications

Time-dependent Hartree-Fock calculations for multinucleon transfer and quasifission processes in theNi64+U238reaction

Time-dependent Hartree-Fock calculations for multinucleon transfer and quasifission processes in theNi64+U238reaction

Analysis of multinucleon transfer reactions with spherical and statically deformed nuclei using a Langevin-type approach

Microscopic description of production cross sections including deexcitation effects

Contact Info

Product

Resources

About