arXiv subjects

Igor Kadenko

Publications and source records attributed to Igor Kadenko.

5 recordsLinked to original sources

arXiv2019

Comparison of Practical Expressions for E1 Photon Strength Functions

The closed-form expressions for the photon strength functions (PSF) are tested using the gamma-decay data of OSLO group. The theoretical calculations are performed for the Lorentzian models of PSF for electric and magnetic dipole gamma-rays. The criteria of minimum of least-square value as well as the root-mean-square deviation factor are used. It is shown that a rather good agreement is obtained within the Simple Modified Lorentzian model for E1 PSF modelling.

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arXiv2016

Effect of gamma-strength on nuclear reaction calculations

The results of the study of gamma-transition description in fast neutron capture and photofission are presented. Recent experimental data were used, namely, the spectrum of prompt gamma-rays in the energy range 2{\div}18 MeV from 14-MeV neutron capture in natural Ni and isomeric ratios in primary fragments of photofission of the isotopes of U, Np and Pu by bremsstrahlung with end-point energies $E_e$= 10.5, 12 and 18 MeV. The data are compared with the theoretical calculations performed within EMPIRE 3.2 and TALYS 1.6 codes. The mean value of angular momenta and their distributions were determined in the primary fragments $^{84}$Br, $^{97}$Nb, $^{90}$Rb, $^{131,133}$Te, $^{132}$Sb, $^{132,134}$I, $^{135}$Xe of photofissions. An impact of the characteristics of nuclear excited states on the calculation results is studied using different models for photon strength function and nuclear level density.

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arXiv2016

Gamma-rays from $^{nat}$Sn and $^{nat}$C induced by fast neutrons

The cross-sections of prompt gamma-ray production from $^{nat}$Sn and $^{nat}$C elements induced by 14.1-MeV neutrons were measured. The time-of-flight technique was used for n-gamma discrimination. The experimental results were compared with theoretical calculations performed by Empire 3.2 and Talys 1.6 codes using different models for photon strength function and nuclear level density.

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arXiv2016

Improvements and Testing Practical Expressions for Photon Strength Functions of E1 Gamma-Transitions

Analytical expression for the E1 photon strength functions (PSF) is modified to account for the low-energy enhancement due to nuclear structure effects (presence of low-energy state (LES)). A closed-form expression of the E1 PSF function includes response of two nuclear states: LES and giant diplole resonance (GDR). Expression for the nuclear response function on electromagnetic field is based on a model of excitation of two coupled damped states. These approach is tested for different data sets for spherical nuclei. Impact on PSF shape of coupling between LES and GDR excitations is considered.

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arXiv2013

Cross Sections of Neutron Reactions $(n,p)$, $(n, \alpha)$, $(n, 2n)$ on Isotopes of Dysprosium, Erbium and Ytterbium at $\sim$ 14 MeV Neutron Energy

The cross sections of the nuclear reactions induced by neutrons at $E_n$= 14.6 MeV on the isotopes of Dy, Er, Yb with emission of neutrons, proton and alpha-particle are studied by the use of new experimental data and different theoretical approaches. New and improved experimental data are measured by the neutron-activation technique. The experimental and evaluated data from EXFOR, TENDL, ENDF libraries are compared with different systematics and calculations by codes of EMPIRE~3.0 and TALYS~1.2. Contribution of pre-equilibrium decay is discussed. Different systematics for estimations of the cross-sections of considered nuclear reactions are tested.

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