Vibrational Enhancement of Nuclear Level Density within Response Function Method

Abstract. The main results are summarized on the development of the response function method for a description of the vibrational state effect on nuclear level density. The enhancement factor is calculated and compared within different approaches. The results of the RF approach are in the better agreement with the ones within the method of attenuated phonon occupation numbers. They also agree reasonably with results of a finite temperature extension of the interacting boson model

Verification of Models for Calculation of E1 Radiative Strength

Photoabsorption cross sections and gamma-decay strength function are calculated and compared with experimental data to test the existing models of dipole radiative strength functions (RSF) for the middle-weight and heavy atomic nuclei. Simplified version of the modified Lorentzian model are proposed. New tables of giant dipole resonance (GDR) parameters are given. It is shown that the phenomenological closed-form models with asymmetric shape can be used for overall estimates of the dipole RSF in the gamma -ray energy region up to about 20 MeV when GDR parameters are known or the GDR systematics can be adopted. Otherwise, the HFB-QRPA microscopic model and the semi-classical approach with moving surface appear to be more adequate methods to estimate the dipole photoabsorption RSF.Comment: 33 pages; 5 figures, 3 tables. Talk given at Workshop on Photon Strength Functions, Prague, Czech Republic, June 17-20, 200

Non-Markovian collision integral in Fermi-systems

The non-Markovian collision integral is obtained on the base of the Kadanoff-Baym equations for Green functions in a form with allowance for small retardation effects. The collisional relaxation times and damping width of the giant isovector dipole resonances in nuclear matter are calculated. For an infinite Fermi liquid the dependence of the relaxation times on the collective vibration frequency and the temperature corresponds to the Landau’s prescription.

E1 gamma-transitions in hot atomic nuclei

New version of the modified Lorentzian approach for radiative strength function is proposed. Renewed systematics for giant dipole resonance (GDR) parameters is given. The gamma-decay strength functions are calculated using renewed GDR parameters and compared with experimental data. It is demonstrated that closed-form approaches with asymmetric shape of the gamma strength, as a rule, provide the reliable simple method for description of gamma-decay processes

AQUACULTURAL CHARACTERISTIC OF FOURTH GENERATION OF COMMON CARP OF THE NYVKA PLANT LINE OF THE SCALELESS INTRABREED TYPE OF THE UKRAINIAN FRAME BREED OF COMMON CARP

Materials of the aquacultural characteristic of the fourth and fifth generation of the Scaleless common carp of the Nyvka Plant Line and reproductive indexes of the females of the fourth selection generation are presented

Description of photoabsorption using photon strength function with the excitation of two resonance states

The results of the use of photon strength function (PSF) of the model of two coupled damped oscillators (Two State Excitations, TSE) for the description of nuclear data for photoabsorption of electric dipole gamma-rays by atomic nuclei are presented. The response function widths dependent on gamma-ray energy were used instead of constant widths in the initial TSE model. It was demonstrated that such a phenomenological approach is a simple method for the description and prediction of the PSF with excitation of both low-energy (pigmy) dipole resonance (PDR) and high-energy giant dipole resonance (GDR). The best description of the experimental photoabsorption cross-sections is obtained at constant width in the PDR range and linear or quadratic energy-dependent width in the GDR range

E1 radiative strength function for gamma-decay and photoabsorption

Photoabsorption cross sections and γ-decay strength function are calculated and compared with experimental data to test the existing models of dipole radiative strength functions (RSF) for the middle-weight and heavy atomic nuclei. Ready-to-use tables of giant dipole resonance parameters with their errors are prepared. Systematics for GDR energy and width are given. It is shown that the phenomenological closed-form models with asymmetric shape can be used for overall estimates of the dipole RSF in the γ-ray energy region up to about 20 MeV, when GDR parameters are known or their systematics can be adopted