Quadrupole and Hexadecapole Vibrational Excitations in Deformed Nuclei

1997 ◽  
Vol 06 (03) ◽  
pp. 437-473 ◽  
Author(s):  
V. G. Soloviev ◽  
A. V. Sushkov ◽  
N. Yu. Shirikova
Keyword(s):  
Experimental Data ◽  
Rare Earth ◽  
Energy Range ◽  
Strength Distribution ◽  
Wave Functions ◽  
Nuclear Model ◽  
Vibrational States ◽  
Deformed Nuclei ◽  
Structure Information ◽  
Vibrational Excitations

Energies, wave functions of the quadrupole and hexadecapole states, B(Eλ) and B(M1) values are calculated within the quasiparticle-phonon nuclear model in a number of well-deformed even-even nuclei in the rare earth region. Reasonably good overall agreement with available experimental data is obtained. Specific properties of the Kπ = 0+ and two-gamma vibrational states are discussed. The distributions of the M1 strength is studied. It is shown that the M1 strength is more strongly fragmented in Er isotopes compared to Gd and Dy isotopes. The fragmentation of one- and two-phonon states is investigated. The fragmentation of one-phonon states strongly affects the Eλ and M1 strength distribution at energies above 2.5–3.0 MeV. The wave functions in the energy range 2–4 MeV contain specific nuclear structure information and these states cannot be treated as chaotic.

DESCRIPTION OF E1 TRANSITION IN DOUBLY EVEN WELL-DEFORMED NUCLEI

1994 ◽  
Vol 03 (04) ◽  
pp. 1227-1250 ◽  
Author(s):  
V.G. SOLOVIEV ◽  
A.V. SUSHKOV ◽  
N. YU. SHIRIKOVA
Keyword(s):  
Experimental Data ◽  
Excited States ◽  
Ground State ◽  
Transition Probabilities ◽  
Wave Functions ◽  
Radial Dependence ◽  
Nuclear Model ◽  
Transition Rates ◽  
Deformed Nuclei ◽  
Dipole Interactions

One-phonon states with Kπ=0− and 1− are calculated within the RPA taking the isoscalar and isovector particle-hole and particle-particle octupole and isovector particlehole dipole interactions into account. General equations of the Quasiparticle-Phonon Nuclear Model are modified. The energies and wave functions of the nonrotational states below 2.3 MeV in 160Gd calculated within this model are in good overall agreement with experimental data. The E1 transition rates in several doubly even well-deformed nuclei are calculated. The influence of the radial dependence of the dipole and octupole interactions on E1 and E3 transition probabilities is investigated. It is shown that the fragmentation of one-phonon states below 2.3 MeV weakly affects the E1 transition rates from 1− states to the ground state. The fragmentation of one- and two-phonon states strongly affect B(E1) values of the transitions from 1− states with energy above 2.5 MeV to the ground states and between excited states. The results of calculating the E1 transition rates are compared with the relevant experimental data.

scholarly journals Study of the neutron-induced fission cross section of 237Np at CERN's n_TOF facility over a wide energy range

2020 ◽  
Vol 239 ◽  
pp. 05006
Author(s):  
A. Stamatopoulos ◽  
A. Tsinganis ◽  
M. Diakaki ◽  
N. Colonna ◽  
M. Kokkoris ◽  
...  
Keyword(s):  
Experimental Data ◽  
Energy Range ◽  
Cross Section ◽  
Fuel Cycle ◽  
Fission Cross Section ◽  
Nuclear Model ◽  
Wide Energy Range ◽  
Model Parameters ◽  
Wide Range ◽  
Induced Fission

Neutron-induced fission cross sections of isotopes involved in the nuclear fuel cycle are vital for the design and safe operation of advanced nuclear systems. Such experimental data can also provide additional constraints for the adjustment of nuclear model parameters used in the evaluation process, resulting in the further development of fission models. In the present work, the 237Np(n,f) cross section was studied at the EAR2 vertical beam-line at CERN's n_TOF facility, over a wide range of neutron energies, from meV to MeV, using the time-of-flight technique and a set-up based on Micromegas detectors, in an attempt to provide accurate experimental data. Preliminary results in the 200 keV – 14 MeV neutron energy range as well as the experimental procedure, including a description of the facility and the data handling and analysis, will be presented.

Representations of sl(3, IR) with half-integral spin bands

1976 ◽  
Vol 54 (11) ◽  
pp. 1114-1123 ◽  
Author(s):  
G. Rosensteel ◽  
D. J. Rowe
Keyword(s):  
Rare Earth ◽  
Harmonic Analysis ◽  
Principal Series ◽  
Algebraic Model ◽  
Wave Functions ◽  
Irreducible Representations ◽  
Deformed Nuclei ◽  
Rare Earth Nuclei ◽  
Integral Spin ◽  
Collective States

A series of irreducible representations of sl(3,IR) is constructed with half-integral spin bands which parallels the principal series of SL(3,IR). While the principal series for SL(3,IR) was shown by Weaver and Biedenharn to be applicable to even–even deformed nuclei, the series constructed here applies to odd mass nuclei. It is shown how parity is included in an SL(3,IR) algebraic model. A second (cuspidal parabolic) series of representations of SL(3,IR) is constructed, which is required for the harmonic analysis of wave functions on SL(3,IR), a necessary preliminary to the application of the results of the SL(3,IR) model in a full microscopic treatment of deformed nuclei. It is shown that the cuspidal parabolic series has undesirable properties for the description of collective states in rare-earth nuclei.

Cross sections for d-3H neutron interactions with samarium isotopes

2016 ◽  
Vol 104 (8) ◽  
Author(s):  
Junhua Luo ◽  
Chunlei Wu ◽  
Li Jiang ◽  
Long He
Keyword(s):  
Experimental Data ◽  
Neutron Flux ◽  
Cross Sections ◽  
Theoretical Calculations ◽  
Nuclear Model ◽  
Activation Technique ◽  
Incident Neutron ◽  
Reaction Threshold ◽  
Talys 1.6 ◽  
The Cross

Abstract:The cross sections for (n,x) reactions on samarium isotopes were measured at (d-T) neutron energies of 13.5 and 14.8 MeV with the activation technique. Samples were activated along with Nb and Al monitor foils to determine the incident neutron flux. Theoretical calculations of excitation functions were performed using the nuclear model codes TALYS-1.6 and EMPIRE-3.2 Malta with default parameters, at neutron energies varying from the reaction threshold to 20 MeV. The results were discussed and compared with experimental data found in the literature. At neutron energies 13.5 and 14.8 MeV, the cross sections of the

Diffusion Coefficients of Interest for the Simulation of Heat Treatment in Rare-Earth Transition Metal Magnets

2012 ◽  
Vol 727-728 ◽  
pp. 163-168 ◽  
Author(s):  
Marcos Flavio de Campos
Keyword(s):  
Experimental Data ◽  
Heat Treatment ◽  
Activation Energy ◽  
Rare Earth ◽  
Transition Metal ◽  
Impurity Atom ◽  
Diffusion Coefficients ◽  
Arrhenius Equation ◽  
Atom Diffusion ◽  
Essential Input

In the case of the modeling of sintering and heat treatments, the diffusion coefficients are an essential input. However, experimental data in the literature about diffusion coefficients for rare-earth transition metal intermetallics is scarce. In this study, the available data concerning diffusion coefficients relevant for rare-earth transition metal magnets are reviewed and commented. Some empirical rules are discussed, for example the activation energy is affected by the size of the diffusing impurity atom. Diffusion coefficients for Dy, Nd and Fe into Nd2Fe14B are given according an Arrhenius equation D=D0exp (-Q/RT). For Dy diffusion into Nd2Fe14B, Q 315 kJ/mol and D08 . 10-4m2/s.

ALPHA-DECAY STUDIES ON 130-153Eu NUCLEI

2013 ◽  
Vol 22 (11) ◽  
pp. 1350081 ◽  
Author(s):  
K. P. SANTHOSH ◽  
B. PRIYANKA
Keyword(s):  
Experimental Data ◽  
Potential Model ◽  
Alpha Decay ◽  
Shell Closure ◽  
Proximity Potential ◽  
Deformed Nuclei ◽  
Neutron Shell ◽  
Good Agreement ◽  
Neutron Shell Closure

The alpha-decay half-lives of the 24 isotopes of Eu (Z = 63) nuclei in the region 130≤A≤153, have been studied systematically within the Coulomb and proximity potential model (CPPM). We have modified the assault frequency and re-determined the half-lives and they show a better agreement with the experimental value. We have also done calculations on the half-lives within the recently proposed Coulomb and proximity potential model for deformed nuclei (CPPMDN). The computed half-lives are compared with the experimental data and they are in good agreement. Using our model, we could also demonstrate the influence of the neutron shell closure at N = 82, in both parent and daughter nuclei, on the alpha-decay half-lives.

A PANORAMA OF CDCC CALCULATIONS FOR DEUTERON INDUCED REACTIONS: FROM ELASTIC CROSS SECTIONS TO INELASTIC AND TRANSFER ONES

2011 ◽  
Vol 20 (04) ◽  
pp. 953-957 ◽  
Author(s):  
P. HUU-TAI CHAU
Keyword(s):  
Experimental Data ◽  
Cross Sections ◽  
Deformed Nuclei ◽  
Coupled Channels ◽  
The Continuum

An overview of calculations performed within the Continuum Discretized Coupled Channels (CDCC) approach for deuteron induced reactions is given. We briefly present an extension of the CDCC formalism which accounts for the target excitations allowing us to determine ( d , d ') cross sections off deformed nuclei. We compare some calculated inelastic cross sections with experimental data. Then it is shown that the CDCC formalism can also be a useful tool to determine ( d , p ) cross sections. This point is illustrated with 54 Cr ( d , p )55 Cr reactions.

Calibration of rare‐earth x‐ray intensifying screens in the 15–70 keV energy range for use on pulsed x‐ray sources

1976 ◽  
Vol 47 (12) ◽  
pp. 1475-1478 ◽  
Author(s):  
L. S. Birks ◽  
J. W. Sandelin ◽  
C. M. Dozier
Keyword(s):  
Rare Earth ◽  
Energy Range ◽  
X Ray
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