I. NUCLEAR PHYSICS

The multimodal approach to fission and the macroscopic-microscopic method for the calculations of charge distribution parameters for isobaric chains have been used to analyze fission product yields. In order to describe the peculiarities of fragment mass curve at very asymmetric mass split, the two narrow fission modes related to the magic numbers Z = 28 and N = 50 were introduced. The reliability of the model’s predicting power was demonstrated by the agreement between calculated and experimental data on the thermal-neutron-induced fission of actinides. It was found that weight of the fission modes related to the spherical doubly-magic clusters (¹³²Sn or ⁷⁸Ni) depends on the neutron-to-proton ratio of a compound system.

3. CALCULATION OF VIBRATIONAL ENHANCEMENT OF NUCLEAR LEVEL DENSITY WITHIN RESPONSE FUNCTION METHOD

The response function approach for description of the vibrational state effects on nuclear level density is analysed. The coefficient of the nuclear level density due to the collective quadrupole vibrations with accounting for damping has been studied as a function of the excitation energy of nucleus. The calculations by the response function approach agree rather-closely with microscopical calculations within finite temperature extension of the interacting boson model and phenomenological calculations where boson partition functions are used with attenuated occupation numbers as well as with complex energies.

V. I. Abrosimov

A semiclassical model based on the solution of the Vlasov kinetic equation for finite systems with a moving surface has been used to study the isoscalar collective modes in heavy spherical nuclei. Within this model, a unified description of both low-energy surface modes and higher-energy giant resonances has been achieved by introducing a coupling between surface vibrations and the motion of single nucleons. An analytical expression for the isoscalar multipole response function can be derived by using a separable approximation for the residual interaction between nucleons. The response function obtained in this way gives a good qualitative description of the isoscalar (monopole, quadrupole and octupole) response in heavy nuclei. Although shell effects are not explicitly included in the theory, our semiclassical response functions are very similar to the quantum ones. This happens because of the well known close relation between classical trajectories and shell structure.

The quasiparticle-phonon nuclear model extended to finite temperature within the framework of the thermo field dynamics is applied to calculate a temperature dependence of the spreading width Γ

of a giant dipole resonance. Numerical calculations are made for

Sn and

Pb nuclei. It is found that the width Γ

increases with T. The reason of this effect is discussed as well as a relation of the present approach to other ones existing in the literature.

6. ULtraheavy nuclei: shell corrections, magic numbers, fission barriers and alpha-decay periods

Proton and neutron shell corrections are calculated for nuclei with proton numbers in the range 76 ≤ Z ≤ 400 along the beta-stability line described by Green’s approximation. Proton and neutron magic numbers are determined for ultraheavy nuclei. Alpha-decay periods and fission barriers of ultraheavy double-magic nuclei are estimated.

The actinide-based hot fusion reactions with stable projectiles heavier than Ca are analyzed within the dinuclear system model for compound nucleus formation. Predictions for several reactions with radioactive beams for the synthesis of heaviest elements are also presented for the future interest. Possibilities of production of new isotopes of superheavy nuclei with charge numbers 104 -108 in incomplete fusion reactions are studied.

8. NONRELATIVISTIC QUANTUM MECHANICS OF THE INTERACTING PARTICLES AND THE COORDINATE - IMPULSE CORRELATION RELATIONS

A quantum mechanical model for a system of interacting bodies, taking into account noncommutativity of the coordinate and impulse operators for different particles and also the correlation equalities, is considered. The noncommutativity of the operators is here the result of the action of interparticle forces and represents natural generalization of the conventional commutation relation between the coordinate and impulse operators for a single particle. The efficiency of the model is evidenced by the specific calculations of well-known systems of atomic physics.

The equation for the nuclear deformational motion in asymmetric potential with two minima is quasi-classically solved. Taking into account the tunneling, we obtained formulas for the energies and wave functions similar to those which were previously derived for the two-band mixing. We have created a theory for the decay out of superdeformed rotational levels based on the exact equations for Green's functions, where both the residual and electromagnetic interactions are treated on equal footing.

10. THE USE OF GLAUBER APPROXIMATION FOR CALCULATION OF TOTAL CROSS SECTIONS OF HYPERTRITON DIFFRACTIVE INTERACTION WITH PROTONS

The calculations of the total cross sections of hypertriton diffractive interaction with protons, carried out precisely and in the Glauber approximation in three cluster model show that this approximation is satisfactory only for rather small (within the limits of experimental errors) values of the hypertriton binding energy.

11. Researches OF SPACIAL DEPENDENCE of fast neutron spectrum form at the outer surface of WWER-1000 pressure vessel

The arrays of data of relations of specific activities of the neutron-activation detectors irradiated at outer surface of WWER-1000 pressure vessel during a number of fuel cycles of Ukrainian NPP units are analyzed by means by of specially developed mathematical device. It is shown that neutron spectrum form at the outer surface at the level of reactor pressure vessel upper shell depends on azimuth coordinate and does not depend on height one.

12. quantum wells degradation and modification of energy spectra in semiconductors under irradiation

The influence of high-energy particles radiation on the spatial distribution of atom concentration in multicomponent semiconductors with quantum wells was considered. The calculations was made for manganese concentration in CdMnTe. The initial distribution of manganese concentration was taken as in Cd_1‑xMn_xTe/CdTe quantum well. Further dynamics was simulated with kinetic equations. Defect creations by irradiation, their recombination and drift to surface as well as manganese diffusion with vacancies and interstitials were taken into account in the kinetic equations. It was shown that irradiation causes the intermixing of compound's components and the quantum well spreading. The influence of external irradiation on the potential for electrons and holes, their spectra and exciton spectra was analyzed. Time dependences of exciton level were calculated for different temperatures and irradiation intensity.

13. The particularities of the formation of radiation defects in silicon with low and high concentration of the oxygen

A. P. Dolgolenko, P. G. Litovchenko, M. D. Varentsov, G. P. Gaidar, A. P. Litovchenko

It has been studied the radiation hardness of the n-Si samples with low and high concentration of oxygen (in range from 5 × 10¹⁵to 7 × 10¹⁷ сm^‑3), which were irradiated by fast-pile neutrons of WWR-M reactor. It has been shown that the fluence of fast-pile neutrons for which the concentration of the electrons tend to intrinsic value does not depend from the concentrations of oxygen. The dose and temperature dependences of the effective concentration of carriers have been measured. The theoretical calculation has been carried out in the framework of Gossik's model, taking into account the recharges of defects not only in n-Si conducting matrix but also in the space-charge region of defect clusters. The necessity of the additional overlapping of the space-charge regions resulting from the introduction of point defects has been shown. The model for explanation of dose dependence for n ® p conversion in n-Si samples with low and high concentrations of the oxygen was proposed. It has been supposed that the space distribution of the assemblage of di-vacancies and Si di-interstitial atoms is responsible for Fermi level position near the midgap under high fluencies.

14. CUMULATIVE EFFECTS OF PROTRACTED IRRADIATION OF CHORNOBYL EXCLUSIVE ZONE PLANTS

The biological and radiobiological peculiarities of seeds and seedlings of the Rumex confertus and Lupinus polycolor plants, which grown during several generations in plots with different level of radionuclide pollution of the Chornobyl exclusive zone have been investigated.

15. SPECIFIC FEATURES OF ¹³⁷Сs MIGRATION AND ACCUMULATION IN CHERNOZEM SOILS OF FOREST ECOSYSTEMS IN THE ZONE CONTAMINATED DUE TO THE CHORNOBYL ACCIDENT

A number of factors influencing ¹³⁷Cs fate and biological availability in chernozem soils under the forest vegetation were assessed for various climatic zones. The migration rates of ¹³⁷Cs in the profile of chernozem soils were shown to depend primary on forest litter composition and structure. In the absence of forest litter the soil mineralogical composition and humus content become the most influential factors of caesium mobility.

16. Influence of natural mineral waters with high contents of iron on free-radical processes and compaund of peripheral blood of the rats irradiated by doze 5,0 Gy

A. J. Moiseev, N. K. Rodionova, N. A. Druzhina, A. I. Lypska, Yu. P. Grinevich, O. B. Ganzha,

The influence of iron-containing mineral water of Dravets deposit on cellular compound and peroxide processes in peripheral blood of rats irradiated at 5,0 Gy was investigated. It was established that the course application of mineral water with high iron concentration can be one of the correction methods of the catalase activity - important blood enzyme of the antioxidant protection.

17. DYNAMICS OF DECREASE OF THE ¹³⁷Cs CONTENTS IN FISHES OF KANEVSKOE RESERVOIR AND COOLING-POND OF ChNPP (1987 - 2004)

O. L. Zarubin, E. N. Volkova, V. V. Beljaev, A. A. Zalissky

The dynamics of ¹³⁷Cs contents in muscles of fishes of cooling-pond of ChNPP and Kanevskoe reservoir was studied in 1987 - 2004. It is revealed, that decrease in the contents of ¹³⁷Cs in muscles of fishes of cooling-pond of ChNPP occurred much more intensively than in fishes of Kanevskoe reservoir. Probably, it is connected with distinctions of hydrological parameters and the temperature condition of these reservoirs.

18. THE INVESTIGATION OF THE ADEQUATENESS OF THE MATHEMATICAL MODEL OF ¹³⁷Cs MIGRATION IN FOREST ECOSYSTEMS OF UKRAINIAN POLISSYA

А. М. Коvalchuk, V. G. Levitsky, І. І. Samolyuk, V. М. Yanchuk, A. A. Orlov

The mathematical model of ¹³⁷Cs migration in forest ecosystem of B₃ type is given. The results of the model adequacy analysis are described. The process of parameterization, numerical analysis and criteria is taking into account, while analyzing the model adequacy has been considered. The main aspects of the automation procedure of the mathematical model adequacy investigation are explained. It gives the possibility of the model application in forestry.

19. The methods of multiparameter correlation measurements For the study of nuclear reactions

Yu. N. Pavlenko, V. O. Kyva, I. N. Kolomiets, V. N. Dobrikov, A. P. Vojter, I. O. Mazny, B. A. Rudenko, O. K. Gorpinich, Yu. Ya. Karlyshev, A. A. Shvedov

The methods and procedures of multi-parameter correlation experiments for the study of nuclear reactions are developed. Computerized measurement system allows to determine the energy of reaction products, their charge and mass, to register and analyze the time and energy correlations of two- or three-particle coincident events. Developed system was tested and used in the experiments for the study of binary and three particle reactions d + ⁶Li and a + ⁷Li.

20. USE OF PROTON BEAM OF THE EPG-10 TANDEM ACCELERATOR AT THE KYIV INSTITUTE FOR NUCLEAR RESEARCH FOR RADIATION IMITATION OF SOLAR BATTERY PHOTOCONVERTERS OF SPACECRAFT EQUIPMENT

V. I. Soroka, M. V. Artsymovych, A. P. Gorban, V. P. Kostylyov, A. V. Sachenko, V. V. Chernenko

Studies of radiation damage imitation of spacecraft equipment solar battery photoconverters is called forth by design of new technologies of silicon photoconverters manufacture for new generation spacecraft equipments (Microsatellite class) at the Institute of Semiconductor Physics of the Academy of Sciences of Ukraine (Kyiv). The technique of imitation testing has been designed. Protons of 4 MeV were used to irradiate samples. The radiation dose was between 10¹¹ and 10¹⁴ protons/cm². The inhomogeneity of the dose to the samples surface was ≤ 1 %. The effect of radiation damage on photoenergy parameters of photoconverters was studied. Feasible mechanisms of the radiation damage effect on such parameters as the short-circuit current, the open-circuit voltage, the fill factor of the volt-ampere characteristic and the efficiency were considered. The degradation of the photoenergy parameters with increased dose was revealed. The studies are planned to be continued.

On the basis of numerical simulation, using the SRІM program and author's programs (INITBEAM, DEGRADBEAM), close optimal structure and geometrical parameters of an exit device of the nuclear microprobe (NMP) with the external beam of ions are determined. Thin films-windows (Sі3N4, Mylar, Kapton or Al) of thickness of 0,2 - 10 microns are used in the exit device. The obtained results allow carrying out the optimized choice of geometrical parameters of the device and films-windows to pass to atmosphere (normal conditions) high energy (2,5 МeV) proton microbeam with the purpose to achieve the minimal degradation of the main ion-optical parameters of the probe on the sample surface. Calculations were used to develop design of the exit device, specialized for a precision irradiation of microscopic samples (living cells) by single ions, of Cracow NMP with the external beam of ions. Some features of this device are discussed in article.