Âdernaâ fizika

A total of 77 experimental values of reaction rates for the (n, 2n), (n, p), (n, pn), (n, α), (n, γ), and (n, f) channels were obtained in the neutron spectrum generated by 21.5 MeV protons irradiating a beryllium target. The measurements were carried out using both natural and highly enriched samples of the following elements: natNi, natZr, natNb, natCd, natTi, natCo, 63,65,natCu, 64Zn, natIn, natAl, natMg, natFe, natAu and natTh. The experiments were performed using the activation technique without destructive analysis of the irradiated samples. Reaction products were measured via γ-ray spectrometry employing two coaxial high-purity germanium (HP Ge) detectors and one planar detector. The acquired γ-spectra were processed using the GENIE2000 software suite. Independent and/or cumulative reaction rates were calculated using the SIGMA code. In total, 77 reaction products were identified, with half-lives ranging from 9.458 minutes (27Mg) to 5.27 years (60Co). The resulting dataset was utilized to assess the predictive capabilities of the PHITS-3.31 code coupled with the JENDL-5 nuclear data library, as applied to the modeling of blanket systems in hybrid reactor facilities.

Using the activation technique without chemical separation, cross sections for the production of 119 fission products — from 72Zn to 151Pm — belonging to 32 different chemical elements (Zn, Ga, Ge, As, Br, Se, Kr, Rb, Sr, Y, Zr, Nb, Mo, Tc, Ru, Rh, Pd, Ag, Cd, In, Sn, Sb, Te, I, Xe, Cs, Ba, La, Ce, Pr, Nd, Pm) were measured under independent irradiation of two metallic 232Th foils with 20.9 MeV protons. The irradiations were carried out at the NS-21M facility, based on the I-2 linear proton accelerator, and lasted 1 hour and 1 minute. The proton flux was determined using monitor reactions natCu(p, x)62Zn and natCu(p, x)63Zn. The obtained results, together with data from other authors available in the EXFOR database and our previously measured data (also included in EXFOR) for proton energies of 100, 200, 800, 1200, and 1600 MeV, are presented in the form of excitation functions and mass yield curves. The fission product cross sections of 232Th were modeled using the PHITS-3.31 code with the INCL4.6/GEM, JAM/GEM, and Bertini/GEM models for 42 proton energies in the range from 0.01 to 3 GeV. Cumulative cross sections for fission products in the mass range 72 < A < 151 were computed using custom software based on the independent cross sections obtained from PHITS-3.31 output. For selected proton energies (20.9, 100, 200, 800, 1200, and 1600 MeV), a comparison between calculated and experimental results was performed using standard statistical criteria (, and ), allowing evaluation of the predictive performance of each model implemented in PHITS-3.31. In addition, the GEF2023/2.1 code was used to analyze the mass yields of 232Th fission products.

The interaction of neutrinos with tellurium nuclei 128 and 130 has been studied, taking into account the influence of charge-exchange resonances. The paper presents calculations of the cross section of solar neutrino capture σ(Eν) by the isotopes 128Te and 130Te. Both experimental data on the strength functions S(E), obtained in the charge-exchange reaction (3He, t) and the S(E) functions calculated within the framework of the microscopic theory of finite Fermi-systems were used. The influence of the resonant structure S(E) on the calculated capture cross sections of solar neutrinos was studied and the contributions of each of the high-lying resonances to the capture cross section σ(Eν) were identified. The contributions of all components of the solar neutrino spectrum were calculated. The contribution of background solar neutrinos to the double beta decay of 130Те nuclei was estimated.

A solution to the relativistic generalization of the four-particle integral Faddeev–Yakubovsky equation is carried out. Only states with zero orbital angular momentum, S states, are considered in the calculations. A rank-one separable potential for the nucleon–nucleon interaction is used to solve the two-nucleon Bethe–Salpeter equation. Calculations are carried out taking into account both the “3 + 1” and “2 + 2” subchannels in the equation. The system of integral equations is solved by the iteration method and the binding energy of the helium-4 nucleus is found. The calculated results are compared with experimental data and nonrelativistic calculations.