Possible reference method of total excitation energy partition between complementary fission fragments

2011 ◽  
Vol 867 (1) ◽  
pp. 12-40 ◽  
Author(s):  
C. Manailescu ◽  
A. Tudora ◽  
F.-J. Hambsch ◽  
C. Morariu ◽  
S. Oberstedt
Keyword(s):  
Excitation Energy ◽  
Reference Method ◽  
Energy Partition ◽  
Fission Fragments ◽  
Total Excitation Energy

ENERGY PARTITION IN 235U FISSION REACTION INDUCED BY THERMAL NEUTRON

2012 ◽  
Vol 21 (08) ◽  
pp. 1250073 ◽  
Author(s):  
YONG-JING CHEN ◽  
JING QIAN ◽  
TING-JIN LIU ◽  
ZHU-XIA LI ◽  
XI-ZHEN WU ◽  
...  
Keyword(s):  
Excitation Energy ◽  
Heavy Fragment ◽  
Incident Neutron ◽  
Shell Effect ◽  
Incident Neutron Energy ◽  
Energy Partition ◽  
Fission Reaction ◽  
Fission Fragments ◽  
Total Excitation Energy ◽  
235U Fission

The partition of the total excitation energy between the fission fragments for the n th +235 U and n(En = 5.55 MeV)+235 U fission reactions are analyzed with the experimental data available. Our results show that the total excitation energy is not shared by the fragments in proportion of their masses but support the so-called energy sorting-mechanism. The temperature of the heavy fragment is generally lower than that of the light one when the shell effect does not play a strong role. As soon as the mass of heavy fragment closes to 132, its temperature becomes higher than the complementary light one because of strong shell effect. Our results also show that the heavy fragments gain more energy than the complementary light ones when the incident neutron energy increases.

scholarly journals Impact of nuclear inertia momenta on fission observables

2018 ◽  
Vol 193 ◽  
pp. 01004
Author(s):  
P. Tamagno ◽  
O. Litaize
Keyword(s):  
Rigid Body ◽  
Excitation Energy ◽  
Nuclear Fission ◽  
Particle Model ◽  
Rotational Inertia ◽  
Neutron Fission ◽  
Fission Fragments ◽  
Rigid Body Model ◽  
Two Parameters ◽  
The Impact

Fission is probably the nuclear process the less accurately described with current models because it involves dynamics of nuclear matter with strongly coupled manybody interactions. It is thus diffcult to find models that are strongly rooted in good physics, accurate enough to reproduce target observables and that can describe many of the nuclear fission observables in a consistent way. One of the most comprehensive current modeling of the fission process relies on the fission sampling and Monte-Carlo de-excitation of the fission fragments. This model is implemented for instance in the FIFRELIN code. In this model fission fragments and their state are first sampled from pre-neutron fission yields, angular momentum distribution and excitation energy repartition law then the decay of both initial fragments is simulated. This modeling provides many observables: prompt neutron and gamma fission spectra, multiplicities and also fine decompositions: number of neutrons emitted as a function of the fragment mass, spectra per fragments, etc. This model relies on nuclear structure databases and on several basic nuclear models describing for instance gamma strength functions or level densities. Additionally some free parameters are still to be determined, namely two parameters describing the excitation energy repartition law, the spin cutoff of the heavy and light fragments and a rescaling parameter for the rotational inertia momentum of the fragments with respect of the rigid-body model. In the present work we investigate the impact of this latter parameter. For this we mainly substitute the corrected rigid-body value by a quantity obtained from a microscopic description of the fission fragment. The independent-particle model recently implemented in the CONRAD code is used to provide nucleonic wave functions that are required to compute inertia momenta with an Inglis-Belyaev cranking model. The impact of this substitution is analyzed on different fission observables provided by the FIFRELIN code.

scholarly journals The 4-dimensional Langevin approach to low energy nuclear fission

2018 ◽  
Vol 169 ◽  
pp. 00005
Author(s):  
F.A. Ivanyuk ◽  
C. Ishizuka ◽  
M.D. Usang ◽  
S. Chiba
Keyword(s):  
Excitation Energy ◽  
Mass Number ◽  
Nuclear Fission ◽  
Deformation Energy ◽  
Low Energy ◽  
Tooth Structure ◽  
Fission Fragments ◽  
Langevin Approach ◽  
Intrinsic Excitation ◽  
Mother Nucleus

We applied the four-dimensional Langevin approach to the description of fission of 235U by neutrons and calculated the dependence of the excitation energy of fission fragments on their mass number. For this we have fitted the compact just-before-scission configuration obtained by the Langevin calculations by the two separated fragments and calculated the intrinsic excitation and the deformation energy of each fragment accurately taking into account the shell and pairing effects and their dependence on the temperature and mass of the fragments. For the sharing of energy between the fission fragments we have used the simplest and most reliable assumption - the temperature of each fragment immediately after the neck rupture is the same as the temperature of mother nucleus just before scission. The calculated excitation energy of fission fragments clearly demonstrates the saw-tooth structure in the dependence on fragment mass number.

The limiting total excitation energy of the nucleus and Levinson's theorem

1988 ◽  
Vol 14 (4) ◽  
pp. L61-L65
Author(s):  
F A Almeida ◽  
Y T Chen ◽  
M S Hussein ◽  
R Donangelo
Keyword(s):  
Excitation Energy ◽  
Levinson’S Theorem ◽  
Total Excitation Energy

scholarly journals Deformation Parameters and Collective Temperature Changes in Photofission Mass Yields of Actinides Within the Systematic Statistical Scission Point Model

2021 ◽  
Vol 9 ◽  
Author(s):  
P. Mehdipour Kadiani
Keyword(s):  
Excitation Energy ◽  
Point Model ◽  
Relative Probability ◽  
Temperature Changes ◽  
Scission Point ◽  
Fission Fragments ◽  
Deformation Parameters ◽  
Initial Excitation ◽  
Complementary Fragment ◽  
Experimental Values

The photofission fragment mass yields of actinides are evaluated using a systematic statistical scission point model. In this model, all energies at the scission point are presented as a linear function of the mass numbers of fission fragments. The mass yields are calculated with a new approximated relative probability for each complementary fragment. The agreement with the experimental data is quite good, especially with a collective temperature Tcol of 2 MeV at intermediate excitation energy and Tcol = 1 MeV for spontaneous fission. This indicates that the collective temperature is greater than the value obtained by the initial excitation energy. The generalized superfluid model is applied for calculating the fragment temperature. The deformation parameters of fission fragments have been obtained by fitting the calculated results with the experimental values. This indicates that the deformation parameters decrease with increasing excitation energy. Also, these parameters decrease for fissioning systems with odd mass numbers.

scholarly journals Cable vibration caused by wind

2018 ◽  
Vol 180 ◽  
pp. 02031
Author(s):  
Irena Golebiowska ◽  
Kazimierz Peszynski
Keyword(s):  
Energy Dissipation ◽  
Excitation Energy ◽  
Large Amplitude ◽  
Dynamic Effect ◽  
Internal Damping ◽  
Paper Briefly ◽  
Cable Vibration ◽  
Low Weight ◽  
Total Excitation Energy ◽  
Excessive Stress

The paper briefly presents selected basic kinds of excitation of cable vibration caused by dynamic effect of wind. It describes the aerodynamic phenomena such as vortex excitation, wind-rain excitation, galloping and buffeting. Cables are structures which are characterised by low internal damping, low rigidity and low weight, so they are not capable of total excitation energy dissipation, hence they can reach large amplitudes of vibration. Large amplitude of vibration causes excessive stress, thereby lowering the safety of the structure.

Additional evidence for fusion-fission inS32+24Mg reactions: Division of excitation energy and spin in the fission fragments

1990 ◽  
Vol 41 (5) ◽  
pp. R1901-R1905 ◽  
Author(s):  
S. J. Sanders ◽  
B. B. Back ◽  
R. V. F. Janssens ◽  
D. G. Kovar ◽  
D. Habs ◽  
...  
Keyword(s):  
Excitation Energy ◽  
Fission Fragments
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