Semi-Empirical Interpretation of Nuclear Masses and Deformations

1964 ◽  
pp. 58-66 ◽  
Author(s):  
Wladyslaw J. Swiatecki
2018 ◽  
Vol 27 (02) ◽  
pp. 1850015 ◽  
Author(s):  
S. Cht. Mavrodiev ◽  
M. A. Deliyergiyev

We formalized the nuclear mass problem in the inverse problem framework. This approach allows us to infer the underlying model parameters from experimental observation, rather than to predict the observations from the model parameters. The inverse problem was formulated for the numerically generalized semi-empirical mass formula of Bethe and von Weizsäcker. It was solved in a step-by-step way based on the AME2012 nuclear database. The established parametrization describes the measured nuclear masses of 2564 isotopes with a maximum deviation less than 2.6[Formula: see text]MeV, starting from the number of protons and number of neutrons equal to 1.The explicit form of unknown functions in the generalized mass formula was discovered in a step-by-step way using the modified least [Formula: see text] procedure, that realized in the algorithms which were developed by Lubomir Aleksandrov to solve the nonlinear systems of equations via the Gauss–Newton method, lets us to choose the better one between two functions with same [Formula: see text]. In the obtained generalized model, the corrections to the binding energy depend on nine proton (2, 8, 14, 20, 28, 50, 82, 108, 124) and ten neutron (2, 8, 14, 20, 28, 50, 82, 124, 152, 202) magic numbers as well on the asymptotic boundaries of their influence. The obtained results were compared with the predictions of other models.


Author(s):  
Roger Hurst ◽  
Valerio Bicego ◽  
Jude Foulds

The small punch or disk bend test has particular value in life prediction of operating equipment since the test requires very small amounts of material (a common test specimen disk is 0.5 mm thick with a diameter of 6 to 10 mm), and usually the required volume of material can be acquired from operating equipment in a virtually nondestructive manner. The application of the small punch (SP) test for creep has gained significant interest in the last decade, primarily as a result of research in Europe. The CEN (one of three European standardization organizations recognized by the EC) has been working to develop a Code of Practice for the small punch test. The Code documents, very recently completed, focus on use of the test for creep rupture and tensile and toughness properties. This paper summarizes the European round-robin work leading to the Code of Practice and key aspects of the Code. Included is a description of the currently recommended semi-empirical interpretation of data from the multiaxially-loaded small punch test specimens, less straightforward than that from conventional uniaxial specimens. As the SP test sees more field use and as the specimen and test configurations achieve better uniformity, we can expect that its application to creep life prediction will increase.


2005 ◽  
Vol 201 ◽  
pp. 453-454
Author(s):  
Kalpana. Duorah ◽  
Aditi. Bezbarua

Massive stars (M ≥ 10M⊙) and supernova are found to be the possible sites for explosive thermonuclear burning. When a massive star collapses, shock waves moving through various convective zones produces explosive situations. The gravitational collapse of a helium exhausted core leads to violent instabilities. The reaction 12C(α, γ)16O is being studied under this condition. Recently it has been found that the coefficients in the semi-empirical mass formula are temperature dependent. Assuming the volume and surface binding to be effective, the nuclear masses, Q values, and reaction rates are calculated. Carbon alpha reaction is found to attain explosive proportion at the high temperature range considered here.


2021 ◽  
pp. 37-52
Author(s):  
Alexander Belyaev ◽  
Douglas Ross

1965 ◽  
Vol 63 (1) ◽  
pp. 1-75 ◽  
Author(s):  
N. Zeldes ◽  
M. Gronau ◽  
A. Lev

Sign in / Sign up

Export Citation Format

Share Document