scholarly journals Fission process of nuclei at low excitation energies with a Langevin approach

2013 ◽  
Vol 88 (4) ◽  
Author(s):  
Y. Aritomo ◽  
S. Chiba
Keyword(s):  
Excitation Energies ◽  
Fission Process ◽  
Langevin Approach

scholarly journals Dynamical Modeling of the Nuclear Fission Process at Low Excitation Energies

2014 ◽  
Vol 02 (05) ◽  
pp. 27-31
Author(s):  
I. I. Gontchar ◽  
M. V. Chushnyakova ◽  
E. P. Oskin ◽  
E. G. Demina
Keyword(s):  
Nuclear Fission ◽  
Excitation Energies ◽  
Dynamical Modeling ◽  
Fission Process

scholarly journals Investigating the fission process at high excitation energies through proton induced reactions on181Ta

2010 ◽  
Vol 8 ◽  
pp. 07011
Author(s):  
Y. Ayyad ◽  
J. Benlliure ◽  
E. Casarejos ◽  
H. Álvarez Pol ◽  
A. Bacquias ◽  
...  
Keyword(s):  
High Excitation ◽  
Excitation Energies ◽  
Fission Process ◽  
Proton Induced Reactions

EXPERIMENTAL STUDY OF p(1 GeV)+natU FISSION–SPALLATION REACTION AND DELAYED NEUTRON MEASUREMENTS

2013 ◽  
Vol 22 (12) ◽  
pp. 1350087 ◽  
Author(s):  
GEDIMINAS STANKUNAS
Keyword(s):  
Experimental Study ◽  
Large Range ◽  
Experimental Studies ◽  
Fission Reactions ◽  
Direct Link ◽  
Spallation Reaction ◽  
Delayed Neutron ◽  
Excitation Energies ◽  
Fission Process ◽  
Fundamental Properties

In this paper, results were obtained in the form of the experimental studies of fission reactions induced by protons in a large range of excitation energies. Some fission product characteristics such as their production yield probabilities and delayed neutron (DV) emission were examined in the dedicated experiment. This paper touches not only fundamental properties of the fission process, but also contains a direct link to various applications.

scholarly journals The description of the excitation energy sharing in nuclear fission within the Langevin approach

2021 ◽  
Vol 256 ◽  
pp. 00007
Author(s):  
F.A. Ivanyuk ◽  
S. Chiba
Keyword(s):  
Excitation Energy ◽  
Mass Number ◽  
Nuclear Fission ◽  
Deformation Energy ◽  
Langevin Equations ◽  
Excitation Energies ◽  
Tooth Structure ◽  
Fission Fragments ◽  
Langevin Approach ◽  
Energy Sharing

We apply the four-dimensional Langevin approach to the description of fission of 235U by neutrons and calculate the dependence of the excitation energy of fission fragments on their mass number. For this we run the Langevin equations until the compound nucleus splits into two separated fragments. This is possible since the we used in this work two-center shell model shape parametrization that describes well both compact and separated shapes. The excitation energies of each fragment are calculated assuming that the temperatures of both fragments are the same. The deformation energy of the fragment immediately after scission is added to its excitation energy. The saw-tooth structure of the dependence neutron multiplicity on the fragment’s mass number in reaction 235U + n at En = 5 Mev is qualitatively reproduced.

scholarly journals Opportunities for detailed fission studies using light charged particle reactions

2020 ◽  
Vol 232 ◽  
pp. 03002
Author(s):  
Birger B. Back
Keyword(s):  
Charged Particle ◽  
Nuclear Physics ◽  
Modern Society ◽  
Decay Chain ◽  
Nuclear Fission ◽  
Quality Data ◽  
Light Charged Particle ◽  
Excitation Energies ◽  
Fission Process ◽  
Detection Techniques

Since its discovery in 1939, the nuclear fission process has provided much insight into the behavior of nuclei under many different conditions. As part of the nuclear chain reaction, the fission process has had a profound impact on modern society and it has consequently attracted much attention to the field of nuclear physics. In this talk, I will argue that the time is ripe for a resumption of studies of the fission process induced by light charged particle reactions. Although fission can be induced in heavy nuclei by several means, in some cases these methods suffer from the complication that fission can occur at several points during the decay chain thus mixing up contributions from different excitation energies. Using instead light charged particle reactions to excite the nuclei in question, the precise excitation energy from which fission takes place, can be determined. In fact, a number of such studies were carried out previously, and a first set of results on fission barrier heights, mass, energy and angular distributions were obtained. Applying detection techniques developed over the last decades will allow researchers to obtain detailed, high-quality data from which to probe and refine our present understanding of the process. Based on these observations, I suggest that substantial advances in the study of this process can be achieved by using simple light charged particle reactions.

Energy Levels and Electromagnetic Transition of 90-94mo Nuclei Using Ibm-1

2020 ◽  
pp. 149-152
Keyword(s):  
Experimental Data ◽  
Transition Probability ◽  
Energy Levels ◽  
Dynamical Symmetry ◽  
Interacting Boson Model ◽  
Excitation Energies ◽  
Electromagnetic Transition ◽  
Boson Model ◽  
Energy States ◽  
Good Agreement

The energy states for the J , b , ɤ bands and electromagnetic transitions B (E2) values for even – even molybdenum 90 – 94 Mo nuclei are calculated in the present work of "the interacting boson model (IBM-1)" . The parameters of the equation of IBM-1 Hamiltonian are determined which yield the best excellent suit the experimental energy states . The positive parity of energy states are obtained by using IBS1. for program for even 90 – 94 Mo isotopes with bosons number 5 , 4 and 5 respectively. The" reduced transition probability B(E2)" of these neuclei are calculated and compared with the experimental data . The ratio of the excitation energies of the 41+ to 21+ states ( R4/2) are also calculated . The calculated and experimental (R4/2) values showed that the 90 – 94 Mo nuclei have the vibrational dynamical symmetry U(5). Good agreement was found from comparison between the calculated energy states and electric quadruple probabilities B(E2) transition of the 90–94Mo isotopes with the experimental data .

scholarly journals Observation of chiral surface excitons in a topological insulator Bi2Se3

2019 ◽  
Vol 116 (10) ◽  
pp. 4006-4011 ◽  
Author(s):  
H.-H. Kung ◽  
A. P. Goyal ◽  
D. L. Maslov ◽  
X. Wang ◽  
A. Lee ◽  
...  
Keyword(s):  
Polarized Light ◽  
Orbit Coupling ◽  
Experimental Investigations ◽  
Composite Particles ◽  
Spin Orbit Coupling ◽  
Spin Orbit ◽  
Excitation Energies ◽  
Circularly Polarized Light ◽  
Pl Emission ◽  
Strong Spin

The protected electron states at the boundaries or on the surfaces of topological insulators (TIs) have been the subject of intense theoretical and experimental investigations. Such states are enforced by very strong spin–orbit interaction in solids composed of heavy elements. Here, we study the composite particles—chiral excitons—formed by the Coulomb attraction between electrons and holes residing on the surface of an archetypical 3D TI,Bi2Se3. Photoluminescence (PL) emission arising due to recombination of excitons in conventional semiconductors is usually unpolarized because of scattering by phonons and other degrees of freedom during exciton thermalization. On the contrary, we observe almost perfectly polarization-preserving PL emission from chiral excitons. We demonstrate that the chiral excitons can be optically oriented with circularly polarized light in a broad range of excitation energies, even when the latter deviate from the (apparent) optical band gap by hundreds of millielectronvolts, and that the orientation remains preserved even at room temperature. Based on the dependences of the PL spectra on the energy and polarization of incident photons, we propose that chiral excitons are made from massive holes and massless (Dirac) electrons, both with chiral spin textures enforced by strong spin–orbit coupling. A theoretical model based on this proposal describes quantitatively the experimental observations. The optical orientation of composite particles, the chiral excitons, emerges as a general result of strong spin–orbit coupling in a 2D electron system. Our findings can potentially expand applications of TIs in photonics and optoelectronics.

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