scholarly journals Nuclear level densities away from line of β-stability

2021 ◽  
Author(s):  
Tanmoy Ghosh ◽  
Bhoomika Maheshwari ◽  
Sangeeta Arora ◽  
Gaurav Saxena ◽  
Bijay Agrawal
Keyword(s):  
Single Particle ◽  
Level Density ◽  
Mass Range ◽  
Density Parameter ◽  
Structural Effects ◽  
Mass Model ◽  
Nuclear Level ◽  
Level Densities ◽  
Shell Effects ◽  
Order Of Magnitude

Abstract The variation of total nuclear level densities (NLDs) and level density parameters with proton number Z are studied around the β-stable isotope, Z0, for a given mass number. We perform our analysis for a mass range A=40 to 180 using the NLDs from popularly used databases obtained with the single-particle energies from two different microsopic mass-models. These NLDs which include microscopic structural effects such as collective enhancement, pairing and shell corrections, do not exhibit inverted parabolic trend with a strong peak at Z0 as predicted earlier. We also compute the NLDs using the single-particle energies from macroscopic-microscopic mass-model. Once the collective and pairing effects are ignored, the inverted parabolic trends of NLDs and the corresponding level density parameters become somewhat visible. Nevertheless, the factor that governs the (Z-Z0) dependence of the level density parameter, leading to the inverted parabolic trend, is found to be smaller by an order of magnitude. We further find that the (Z-Z0) dependence of NLDs is quite sensitive to the shell effects.

Influence of nuclear deformation on level density parameter

2016 ◽  
Vol 31 (37) ◽  
pp. 1650211
Author(s):  
S. A. Alavi ◽  
V. Dehghani
Keyword(s):  
Single Particle ◽  
Level Density ◽  
Field Potential ◽  
Density Parameter ◽  
Nuclear Level Density ◽  
Nuclear Level ◽  
Level Density Parameter ◽  
Single Particle Level ◽  
Significant Difference ◽  
Particle Level

By using semiclassical method and considering deformed Woods–Saxon mean field potential, single-particle level density g, level density parameter a, and nuclear level density have been calculated for some deformed nuclei with deformation parameters ([Formula: see text], [Formula: see text]). Significant difference between deformed and spherical level density parameter and nuclear level density were observed. The effect of [Formula: see text] on level density parameter was notable. A simple formula for single-particle level density has been introduced.

NUCLEAR LEVEL DENSITY OF HEAVY NUCLEI Z≥90 THROUGH SEMICLASSICAL METHOD

2014 ◽  
Vol 29 (03) ◽  
pp. 1450017 ◽  
Author(s):  
M. R. PAHLAVANI ◽  
S. A. ALAVI ◽  
E. FARHADI
Keyword(s):  
Excitation Energy ◽  
Single Particle ◽  
Level Density ◽  
Energy Shift ◽  
Density Parameter ◽  
Heavy Nuclei ◽  
Nuclear Level Density ◽  
Nuclear Level ◽  
Single Particle Level ◽  
Particle Level

The nuclear level density parameters of back shift Fermi gas model, including single-particle level density parameter a and excitation energy shift E1, for some heavy nuclei have been calculated in the framework of semiclassical approach. The single-particle level density have been obtained for mean-field Woods–Saxon potential. By using the obtained values of single-particle level density parameter and excitation energy shift, the spin cut-off factor has been calculated at the neutron binding energy.

scholarly journals Ignatyuk damping factor: A semiclassical formula

2019 ◽  
Vol 28 (08) ◽  
pp. 1950061 ◽  
Author(s):  
Nishchal R. Dwivedi ◽  
Saniya Monga ◽  
Harjeet Kaur ◽  
Sudhir R. Jain
Keyword(s):  
Level Density ◽  
Model Fitting ◽  
Damping Factor ◽  
Density Parameter ◽  
Nuclear Level Density ◽  
Nuclear Level ◽  
Gamma Energy ◽  
Level Density Parameter ◽  
Shell Effects ◽  
Semiclassical Methods

Data on nuclear-level densities extracted from transmission data or gamma energy spectrum store the basic statistical information about nuclei at various temperatures. Generally, this extracted data goes through model fitting using computer codes like CASCADE. However, recently established semiclassical methods involving no adjustable parameters to determine the level density parameter for magic and semi-magic nuclei give a good agreement with the experimental values. One of the popular ways to paramaterize the level density parameter which includes the shell effects and its damping was given by Ignatyuk. This damping factor is usually fitted from the experimental data on nuclear-level density and it comes around 0.05 [Formula: see text]. In this work, we calculate the Ignatyuk damping factor for various nuclei using semiclassical methods.

NUCLEAR LEVEL DENSITY AT FINITE TEMPERATURES

2006 ◽  
Vol 15 (02) ◽  
pp. 478-483 ◽  
Author(s):  
J. BARTEL ◽  
K. POMORSKI ◽  
B. NERLO-POMORSKA
Keyword(s):  
Single Particle ◽  
Level Density ◽  
Mean Field ◽  
Skyrme Force ◽  
Nuclear Level Density ◽  
Nuclear Level ◽  
Level Densities ◽  
Relativistic Mean Field ◽  
Single Particle Level ◽  
Particle Level

Selfconsistent mean-field calculations have been performed with the SkM* Skyrme force for 140 spherical even-even nuclei at temperatures 0≤T≤4 MeV . Single-particle level densities for this sample of nuclei are determined for various temperatures. The average dependence of the single-particle level density on mass number A and isospin is given and compared with previous estimates obtained using the relativistic mean-field and different semiclassical approaches.

scholarly journals Level studies of 73As via 73Ge(p, nγ)73As reaction and density of discrete levels in 73As

2009 ◽  
Vol 24 (2) ◽  
pp. 82-85 ◽  
Author(s):  
Aziz Behkami ◽  
Rohallah Razavi ◽  
Tayeb Kakavand
Keyword(s):  
Proton Beam ◽  
Excited States ◽  
Level Scheme ◽  
Level Density ◽  
Fermi Gas ◽  
Temperature Model ◽  
Nuclear Level Density ◽  
Nuclear Level ◽  
Level Densities ◽  
Experimental Level

The excited states of 73As have been investigated via the 73Ge(p, n?)73As reaction with the proton beam energies from 2.5-4.3 MeV. The parameters of the nuclear level density formula have been determined from the extensive and complete level scheme for 73As. The Bethe formula for the back-shifted Fermi gas model and the constant temperature model are compared with the experimental level densities.

scholarly journals TEMPERATURE DEPENDENCE OF THE NUCLEAR ENERGY IN RELATIVISTIC MEAN-FIELD THEORY

2005 ◽  
Vol 14 (03) ◽  
pp. 505-511 ◽  
Author(s):  
B. NERLO-POMORSKA ◽  
K. POMORSKI ◽  
J. SYKUT ◽  
J. BARTEL
Keyword(s):  
Single Particle ◽  
Level Density ◽  
Mean Field Theory ◽  
Mean Field ◽  
Correction Method ◽  
Shell Correction ◽  
Shell Effects ◽  
Relativistic Mean Field ◽  
Single Particle Level ◽  
Particle Level

Self-consistent relativistic mean-field (RMF) calculations with the NL3 parameter set were performed for 171 spherical even-even nuclei with 16≤A≤224 at temperatures in the range 0≤T≤4 MeV . For this sample of nuclei single-particle level densities are determined by analyzing the data obtained for various temperatures. A new shell-correction method is used to evaluate shell effects at all temperatures. The single-particle level density is expressed as function of mass number A and relative isospin I and compared with previous estimates.

Shell Effects on Nuclear Level Densities

1972 ◽  
Vol 5 (3) ◽  
pp. 1124-1126 ◽  
Author(s):  
V. S. Ramamurthy ◽  
S. K. Kataria ◽  
S. S. Kapoor
Keyword(s):  
Nuclear Level ◽  
Level Densities ◽  
Shell Effects

scholarly journals Angular momentum dependence of the nuclear level density parameter

2014 ◽  
Vol 66 ◽  
pp. 03073 ◽  
Author(s):  
M. Gohil ◽  
Pratap Roy ◽  
K. Banerjee ◽  
S. Bhattacharya ◽  
C. Bhattacharya ◽  
...  
Keyword(s):  
Angular Momentum ◽  
Level Density ◽  
Density Parameter ◽  
Momentum Dependence ◽  
Nuclear Level Density ◽  
Nuclear Level ◽  
Level Density Parameter

Nuclear level-density parameter in hot nuclei

1989 ◽  
Vol 40 (3) ◽  
pp. 1510-1512 ◽  
Author(s):  
W. E. Ormand ◽  
P. F. Bortignon ◽  
A. Bracco ◽  
R. A. Broglia
Keyword(s):  
Level Density ◽  
Density Parameter ◽  
Nuclear Level Density ◽  
Nuclear Level ◽  
Level Density Parameter ◽  
Hot Nuclei
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