scholarly journals Determination of nuclear level densities from experimental information

1994 ◽  
Vol 50 (4) ◽  
pp. 1913-1916 ◽  
Author(s):  
B. J. Cole ◽  
N. J. Davidson ◽  
H. G. Miller
Keyword(s):  
Experimental Information ◽  
Nuclear Level ◽  
Level Densities

scholarly journals Determination of the nuclear level densities and radiative strength function for 43 nuclei in the mass interval 28≤A≤200

2018 ◽  
Vol 169 ◽  
pp. 00007
Author(s):  
David Knezevic ◽  
Nikola Jovancevic ◽  
Anatoly M. Sukhovoj ◽  
Ludmila V. Mitsyna ◽  
Miodrag Krmar ◽  
...  
Keyword(s):  
Nuclear Physics ◽  
Good Description ◽  
Strength Function ◽  
Mass Region ◽  
Nuclear Level ◽  
Characteristic Structure ◽  
Level Densities ◽  
Practical Model ◽  
Strength Functions

The determination of nuclear level densities and radiative strength functions is one of the most important tasks in low-energy nuclear physics. Accurate experimental values of these parameters are critical for the study of the fundamental properties of nuclear structure. The step-like structure in the dependence of the level densities p on the excitation energy of nuclei Eex is observed in the two-step gamma cascade measurements for nuclei in the 28 ≤ A ≤ 200 mass region. This characteristic structure can be explained only if a co-existence of quasi-particles and phonons, as well as their interaction in a nucleus, are taken into account in the process of gamma-decay. Here we present a new improvement to the Dubna practical model for the determination of nuclear level densities and radiative strength functions. The new practical model guarantees a good description of the available intensities of the two step gamma cascades, comparable to the experimental data accuracy.

Determination of Nuclear Level Densities at an Excitation Energy of 20 MeV

1965 ◽  
Vol 138 (6B) ◽  
pp. B1372-B1377 ◽  
Author(s):  
H. K. Vonach ◽  
J. R. Huizenga
Keyword(s):  
Excitation Energy ◽  
Nuclear Level ◽  
Level Densities

A COMPOSITE NUCLEAR-LEVEL DENSITY FORMULA WITH SHELL CORRECTIONS

1965 ◽  
Vol 43 (8) ◽  
pp. 1446-1496 ◽  
Author(s):  
A. Gilbert ◽  
A. G. W. Cameron
Keyword(s):  
Lower Energy ◽  
Level Density ◽  
Energy Levels ◽  
Fermi Gas ◽  
Experimental Information ◽  
Shell Correction ◽  
Nuclear Level Density ◽  
Excitation Energies ◽  
Nuclear Level ◽  
Level Densities

At low excitation energies a "constant nuclear temperature" representation of nuclear-level densities is used, and at high excitation energies the regular Fermi gas formula is adopted. A method is developed for determining the parameters of the Fermi gas formula by using both the pairing and the shell-correction energies found by Cameron and Elkin for their semiempirical atomic mass formula in its exponential form. This procedure determines level densities at neutron-binding-energy excitations subject to an average factor error of 1.8. Methods are also developed for determining the parameters for the lower-energy formula in such a way that it best fits the lower-energy levels and joins smoothly to the Fermi gas formula. Correlations of the resulting parameters with shell and pairing effects are found. A composite prescription is given for calculating level densities in nuclei for which no experimental information is known. Tables give level density parameters for a wide variety of nuclei for which some experimental information is known. Some of the derivations of the Fermi gas formula in the literature were found to be slightly incorrect, so new derivations are presented in Appendixes.

scholarly journals Microscopic calculation of symmetry projected nuclear level densities

2009 ◽  
Vol 79 (2) ◽  
Author(s):  
K. Van Houcke ◽  
S. M. A. Rombouts ◽  
K. Heyde ◽  
Y. Alhassid
Keyword(s):  
Nuclear Level ◽  
Level Densities ◽  
Microscopic Calculation

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.

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