No abstract available

No abstract available

[en] In the work the ⁷Li(p, α)⁴He and ⁷Li(d, p)⁸Li reactions were calculated within the framework of the distorted wave method with using of the DWUCK5 code. At calculation the ⁷Li(p, α)⁴He reaction the cluster folding-potential of the ⁷Li-p system interaction and a deep αα-potential of the Gauss form containing the forbidden states by the Pauli principle are used. In capacity of the vertex functions of the t-p system Shepard form factor was used. Wave function of the αt coupled system have being generated in thee deep potential obtaining forbidden states by Pauli potential. At calculation of the ⁷Li(d, p)⁸Li reaction the cluster folding-potential of ⁷Li-d and ⁸Li-p systems interactions are used. In capacity of the vertex functions of the n-p system Raid form factor was used. Wave function of the ⁷Li-n coupled state system was produced from the three-particle αtn wave function of the ⁸Li nucleus. From the obtained cross sections the astrophysical S-factors were excerpted

[en] In the given work the S-factors for ⁹Be(p, γ)¹⁰B, ¹¹Be(p, γ)¹²C, ^12,13C(p, γ)^13,14N, ¹⁴N(p, γ)¹⁵O, ¹⁶O(p, γ)¹⁷F reactions were calculated from experimental values of total cross-sections, and from cross-sections calculated within the framework of direct and resonant radiative capture models. The permeability of a barrier was calculated by using of Gamov's formula. Calculation of cross sections of reaction of protons capture by nuclei ⁹Be, ¹⁴N and ¹²C were carried by using of phenomenological optical potentials received from the analysis of experimental data on elastic scattering of protons for these nuclei within the framework of optical model. For calculation of cross sections on nuclei ⁹Be and ¹⁶O cluster folding - potentials was used. In cluster folding - potentials, the cluster-cluster interaction are folded by density of the investigated nuclei. In case of ¹⁴N(p, γ)¹⁵O reaction nucleon-nucleon folding-potential also was used received by folding of nucleon-nucleon potential with nucleons density of a nucleus ¹⁴N, determined from the data on electronic scattering. Spectroscopic factor for connection of protons to researched nuclei undertook from Bojarkina's work. The results of our estimations for S-factors were compared with experimental and theoretical values from the literatures. The comparison shows, that the available ambiguity of these values is not completely eliminated. In particular, sub threshold resonances, which characteristics precisely are not determined, can give the significant contribution to the S-factor of reaction ¹⁴N(p, γ)¹⁵O, to account them a more additional researches are required

No abstract available

[en] A theoretical study of radiative capture reactions of protons on nuclei allow to obtain both truly nuclear information about structure of nuclei, energy spectra and a nuclear fusion, an elements occurrence and so on. Besides, the study of these reactions is necessary for diagnostics of thermonuclear plasma and a search of new alternative kinds of fuel for controlled thermonuclear fusion. However during the extraction of astrophysical data from the reactions there are observed the difficulties, which are connected with existence of wide resonance in the total cross section of the reactions give a direct capture. Within the framework of the method of distorted waves there were made calculations of differential cross sections of the reaction of radiative capture for E1, E2, and M1 transitions. To describe the input channel there was used a phenomenological optical potential. This potential was obtained from analysis of experimental data of elastic scattering of proton by nuclei. Fixing geometrical parameters depth of potential was varied. Then energy dependence of parameters was deduced. These approach for extraction of potential parameters from experimental data were applied for protons interaction with ⁹Be, ¹⁴N and ¹²C nuclei. Another approach for obtaining of an interaction potential of proton with the nucleus is a cluster-folding potential. In this approach a nuclear target was considered as the cluster system (thus an internal structure of clusters did not considered) and folding procedure was conducted by cluster-cluster interaction and cluster density. Cluster-folding potential was used for interaction of protons with ⁹Be and ¹⁶O nuclei. Potentials obtained in these both approach were applied for calculation of radiative capture reaction ⁹Be(p, γ)¹⁰B, ¹¹B(p, γ)¹²C, ^12,13C(p, γ)^13,14N, ¹⁴N(p, γ)¹⁵O, ¹⁶O(p, γ)¹⁷F. Results of calculation are compared with data of other works and experimental data. Comparison of our results with results of other works shows that there are difficulties, connected with using potentials, which have a large radius and shallow depth. Because these potentials give a small height of potential barrier, and as consequence increased cross section of reactions at astrophysical energy range

No abstract available

[en] The differential cross section and S-factor of ⁹Be(p,γ)¹'0Be reaction are calculated by using cluster folding potential. Cluster folding potential is compared with phenomenological potential. The thermonuclear reaction rates of (σν)⁹Be(p,γ)¹'0Be reaction are calculated for Maxwellian distribution in energy range 001-1.75 T₉ K. Results of calculations are compared with other data. (author)

[en] Reaction of radiation capture of protons by nucleus ¹⁴N is one of important reactions of CNO-cycle, which produces energy in main-sequence stars with masses are larger than solar ones. In the range of low energies (from hundreds keV to 1 MeV) absolute values of cross sections measured by different groups of authors differ in several times; value extrapolation of astrophysical S-factor to 0 to different levels of ¹⁵O nucleus results also in different values, which sometimes differ by order. There were measured differential cross-sections of the reaction ¹⁴N(p, γ) and determined angular distributions of gamma-radiation at the accelerator of heavy ions UKP-2-1 at the Laboratory of Low-energy Nuclear Reactions of the Institute of Nuclear Physics of National Nuclear Center of the Republic of Kazakhstan for more precise definition of existing values. Taking into account an anisotropy of the angular distribution of gamma-rays there were obtained total cross sections of the reaction ¹⁴N(p, γ) in the energy region of from 880 keV to 1200 keV. Measurements of gamma-spectra were carried out by two detectors: the first one was of super pure germanium (its volume was 111 cm³, the firm 'ORTEG') the second one was of Ge(Li) (its volume was 40 cm³). The calibration of the detectors on an efficiency of gamma-rays detection was carried out with use of the calibration gamma-source ⁵⁶Co, manufactured in the cyclotron of the Institute, and the standard sources ¹³⁷Cs and ⁵⁶Co. The efficiency of the detector in the high-energy region of up to E_γ=10.8 MeV was determined with use of the reaction ²⁷Al(p, γ)²⁸Si. During the measurements of gamma-spectra the distance from the beam spot on the irradiated target to the surface of the detector was 4 cm. The current of the proton beam on the target was equal to (10-15) μA. The measurements of differential cross section of the reaction ¹⁴N(p, γ) were carried out at angles Θ=(0, 45, 90 and 126 Deg.) to the direction of the proton beam. As targets there were used fine films of niobium nitride (NbN), deposited by spraying onto copper base, with natural composition of nitrogen and with thicknesses of (5-100) μg/cm². Differential cross sections of the reaction ¹⁴N(p, γ) were measured in the region of the resonance (E_R=1058 keV) and at points of the predominance of the mechanism of direct capture with proton energies of E_p=850, 1100 and 1200 keV. In the resonance maximum with energy 1058 keV the differential cross section equal 12.16 mb/sr for transition to the 5241 keV state, 9.38 mb/sr - for transition 5241→0 keV and 7.72 mb/sr - for transition from continued spectrum to the ground state, that is in agreement with the known data. The total cross section of this level is calculated in the direct capture model, from which astrophysical S-factor was obtained. There was carried out polynomial extrapolation of S-factor to 0 energy, which is compared with the results of other authors

No abstract available