2.2.4.8 Nuclear excitation energies and production of cascade nucleons

2005 ◽  
pp. 96-98
Author(s):  
A. Fasso ◽  
K. Göbel ◽  
M. Höfert ◽  
J. Ranft ◽  
G. Stevenson
Keyword(s):  
Nuclear Excitation ◽  
Excitation Energies

scholarly journals Energy dependence of exotic nuclei production cross sections by photofission reaction in GDR range

2016 ◽  
Vol 94 (2) ◽  
pp. 243-248 ◽  
Author(s):  
Debasis Bhowmick ◽  
F.A. Khan ◽  
Debasis Atta ◽  
D.N. Basu ◽  
Alok Chakrabarti
Keyword(s):  
Charge Distribution ◽  
Cross Sections ◽  
Giant Dipole Resonance ◽  
Production Cross ◽  
Nuclear Excitation ◽  
Excitation Energies ◽  
Mass Distributions ◽  
Gdr Region ◽  
Dipole Resonance ◽  
Average Photon Energy

Photofission of actinides is studied in the region of nuclear excitation energies that covers the entire giant dipole resonance (GDR) region. The mass distributions of 238U photofission fragments have been explored theoretically for eight different endpoint bremsstrahlung energies from 11.5 to 67.7 MeV, which correspond to average photon energies of 9.09 to 15.90 MeV. Among these energies, 29.1 MeV corresponds to the average photon energy of 13.7 ± 0.3 MeV, which coincides with the GDR peak for 238U photofission. The integrated yield of 238U photofission, as well as charge distribution of photofission products, is calculated and its role in producing nuclei and their neutron-richness is investigated.

Determination of nuclear excitation energies from the number of evaporated particles

2005 ◽  
Vol 68 (11) ◽  
pp. 1787-1789
Author(s):  
V. A. Ditlov ◽  
V. V. Dubinina ◽  
N. P. Egorenkova ◽  
V. I. Krotkova ◽  
E. A. Pozharova ◽  
...  
Keyword(s):  
Nuclear Excitation ◽  
Excitation Energies

scholarly journals Statistical Fluctuations of Energy Spectra in the Isobar A = 68 Nuclei

2021 ◽  
pp. 496-504
Author(s):  
Adel. K. Hamoudi ◽  
Hayder A. Abd Alabas
Keyword(s):  
Shell Model ◽  
Matrix Theory ◽  
Energy Spectra ◽  
Nuclear Excitation ◽  
Excitation Energies ◽  
Gaussian Shape ◽  
Model Calculations ◽  
Level Densities ◽  
Statistical Fluctuations ◽  
Inert Core

Statistical fluctuations of nuclear energy spectra for the isobar A = 68 were examined by means of the random matrix theory together with the nuclear shell model. The isobar A = 68 nuclei are suggested to consist of an inert core of 56Ni with 12 nucleons in f5p-space (2p3/2, 1f5/2 and 2p1/2 orbitals). The nuclear excitation energies, required by this work, were obtained through performing f5p-shell model calculations using the isospin formalism f5pvh interaction with realistic single particle energies. All calculations of the present study were conducted using the OXBASH code. The calculated level densities were found to have a Gaussian shape. The distributions of level spacing P(s) and  statistic for the considered classes of states, obtained with full Hamiltonian of f5pvh (absence of the off-diagonal Hamiltonian) calculations, showed a chaotic (regular) behavior and coincided well with the distribution of Gaussian orthogonal ensemble (Poisson). Moreover, these distributions were independent of spin (J) and isospin (T)

Multipole excitations in nuclear muon capture and mean nuclear excitation energies

1975 ◽  
Vol 12 (1) ◽  
pp. 28-35 ◽  
Author(s):  
D. Duplain ◽  
B. Goulard ◽  
J. Joseph
Keyword(s):  
Muon Capture ◽  
Nuclear Excitation ◽  
Excitation Energies

Measuring nuclear excitation energies and Q-values with a cyclotron-magnetic spectrograph system

1974 ◽  
Vol 115 (1) ◽  
pp. 189-196 ◽  
Author(s):  
J.A. Nolen ◽  
G. Hamilton ◽  
E. Kashy ◽  
I.D. Proctor
Keyword(s):  
Nuclear Excitation ◽  
Excitation Energies ◽  
Q Values

Nuclear muon-capture sum rules and mean nuclear excitation energies

1974 ◽  
Vol 10 (5) ◽  
pp. 2034-2044 ◽  
Author(s):  
B. Goulard ◽  
H. Primakoff
Keyword(s):  
Sum Rules ◽  
Muon Capture ◽  
Nuclear Excitation ◽  
Excitation Energies

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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