Anisotropy of the angular distribution of fission fragments in heavy-ion fusion-fission reactions: The influence of the level-density parameter and the neck thickness

By using semiclassical method and considering Woods–Saxon and Coulomb potentials, the level density parameter a was calculated for three superheavy nuclei 270110, 278112 and 290116. Obtained results showed that the value of level density parameter of these nuclei is near to the simple relation a ≈ A/10. In framework of the dinuclear system model, the effects of level density parameter on the probability of the formation of a compound nucleus, the ratio of neutron emission width and fission width, and evaporation residue cross-section of three cold fusion reactions 62 Ni +208 Pb , 70 Zn +208 Pb and 82 Se +208 Pb , leading to superheavy elements were investigated. The findings indicate that the level density parameter play a significant role in calculations of heavy-ion fusion–fission reactions. The obtained results in the case of a = A/12 have larger values in comparison with calculated level density parameter with Woods–Saxon potential (a WS ) and a = A/10. The theoretical results of the evaporation residue cross-section are very sensitive to the choice of level density parameter. The calculated values with a WS are in good agreement with experimental values.

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DYNAMICAL SIMULATION OF EMISSION ANGLE DEPENDENCE OF FRAGMENTS SPIN IN HEAVY ION FUSION–FISSION REACTIONS

International Journal of Modern Physics E ◽

10.1142/s0218301310015850 ◽

2010 ◽

Vol 19 (07) ◽

pp. 1451-1461 ◽

Cited By ~ 3

Author(s):

M. R. PAHLAVANI ◽

D. NADERI ◽

S. M. MIRFATHI

Keyword(s):

Experimental Data ◽

Heavy Ion ◽

Emission Angle ◽

Fission Reactions ◽

Angle Dependence ◽

Dynamical Simulation ◽

Deformation Parameters ◽

Average Spin ◽

Neck Thickness ◽

Heavy Ion Fusion

In this paper, a formalism consisting of multi-dimensional Langevin equation (LE) and Scission point Transition State Model (SCTSM) have been applied to study the angle dependence of fragment's average spin for 16 O + 209 Bi and 16 O + 232 Th systems. The influence of asymmetry and deformation parameters, neck thickness of compound nucleus and pre-scission neutron multiplicity on the fragment's average spin is discussed. Results obtained using this approach are in better agreement with the experimental data as compared with the SCTSM.

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Mass-split dependence of pre-scission neutron multiplicity by four-dimensional Langevin dynamics in 16,18O, 40Ar and 64Ni-induced fusion–fission reactions

International Journal of Modern Physics E ◽

10.1142/s0218301319500770 ◽

2019 ◽

Vol 28 (09) ◽

pp. 1950077

Author(s):

D. Naderi ◽

S. A. Alavi ◽

V. Dehghani

Keyword(s):

Asymmetry Parameter ◽

Reasonable Agreement ◽

Neutron Emission ◽

Level Density ◽

Neutron Multiplicity ◽

Density Parameter ◽

Fission Reactions ◽

Orientation Degree ◽

Langevin Model ◽

Neck Thickness

By using the multidimensional Langevin model, including elongation, neck thickness, asymmetry parameter and orientation degree of freedom, the fission dynamics of some [Formula: see text]O-, [Formula: see text]Ar- and [Formula: see text]Ni-induced fusion–fission reactions were investigated. We calculated mean pre-scission neutron kinetic energy, pre-scission neutron multiplicity and fission time. Mass-split dependence of pre-scission neutron multiplicity and sensitivity of multiplicity on different value of the level density parameter for fission and neutron emission of highly excited compound nuclei were studied. One can conclude reasonable agreement between theory and tentative results for different reactions.

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Investigation of level density parameter dependence for some 233U, 235U, 237U, 239U, 249Cf, 251Cf, 237Pu and 247Cm nuclei in neutron fission cross sections with the incident energy up to 20 MeV

Kerntechnik ◽

10.1515/kern-2020-0086 ◽

2021 ◽

Vol 86 (1) ◽

pp. 78-85

Author(s):

Ö. Sönmez ◽

O. Karaman

Keyword(s):

Cross Sections ◽

Nuclear Reactions ◽

Level Density ◽

Medical Application ◽

Density Parameter ◽

Fission Reactions ◽

Neutron Fission ◽

Level Density Parameter ◽

Nuclear Data Library ◽

The Cross

Abstract Level density models have increasing importance to gain more in-depth into the nature of nuclear reactions. Many novel and advanced medical application use radioisotopes, which are produced with nuclear reactions. In this study, the effect of the level density parameters of the nucleus on the cross sections of neutron-fission reactions for 233U, 235U, 237U, 239U, 249Cf, 251Cf, 237Pu and 247Cm nuclei were investigated for up to 20 MeV neutrons. TALYS 1.8 software was used to calculate the cross-sections of neutron-fission reactions for different level density parameters. The calculations were compared with the EXFOR nuclear data library and the level density parameters, and the closest fit were searched. As outputs of the study, the effect of selection of level density parameter on cross section calculations was observed. The theoretically obtained data were compared with the experimental data taken from the literature. The results are presented graphically for better interpretation.

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Time of flight (TOF) spectrometer for accurate measurement of mass and angular distribution of fission fragments in heavy ion induced fission reactions

Nuclear Instruments and Methods in Physics Research Section A Accelerators Spectrometers Detectors and Associated Equipment ◽

10.1016/j.nima.2004.11.029 ◽

2005 ◽

Vol 540 (2-3) ◽

pp. 285-294 ◽

Cited By ~ 21

Author(s):

T.K. Ghosh ◽

S. Pal ◽

T. Sinha ◽

S. Chattopadhyay ◽

K.S. Golda ◽

...

Keyword(s):

Angular Distribution ◽

Time Of Flight ◽

Heavy Ion ◽

Fission Reactions ◽

Fission Fragments ◽

Induced Fission

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DYNAMICAL SIMULATION OF FISSION FRAGMENTS AVERAGE KINETIC ENERGY IN HEAVY-ION FUSION–FISSION REACTIONS

Modern Physics Letters A ◽

10.1142/s0217732311035341 ◽

2011 ◽

Vol 26 (13) ◽

pp. 975-985 ◽

Cited By ~ 2

Author(s):

M. R. PAHLAVANI ◽

D. NADERI ◽

S. M. MIRFATHI

Keyword(s):

Kinetic Energy ◽

Three Dimensional ◽

Heavy Ion ◽

Langevin Equations ◽

Average Kinetic Energy ◽

Mass Asymmetry ◽

Fission Fragments ◽

Neck Thickness ◽

Dynamical Parameters ◽

Heavy Ion Fusion

Monte Carlo simulation based on the three-dimensional Langevin equations and one-body dissipation mechanism has been applied to highly excited compound nucleus to investigate the kinetic energy distribution of fission fragments. The effect of center to center distance between nascent fragments and other dynamical parameters (elongation, neck thickness and mass asymmetry) on average kinetic energy of fragments also studied. Finally, obtained results using this approach are compared with earlier theoretical and experimental data for a few typical systems.

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