Study of photonuclear reactions with the alpha particles' emission on zirconium, niobium, and molybdenum.

Photonuclear reactions with the emission of protons and alpha particles have been little studied experimentally since their cross-sections are much smaller than those of the (γ, n) channel due to the Coulomb barrier. However, the study of such reactions is of great applied interest to producing medical isotopes. Besides, experimental data on photonuclear reactions with the emission of charged particles for nuclei with Z = 40, 41, 42 open up great opportunities for learning the role of magic numbers. In the presented article, we obtained the weighted average yields of (γ, αn)-reactions for natural zirconium, niobium, and molybdenum at bremsstrahlung γ-quanta of 20 MeV boundary energy for the first time. A significant effect of a closed N = 50 shell was established on the reaction yield with the emission of alpha particles. Our research shows that the semi-direct mechanism for (γ, αn) reactions dominates in the energy range below the Coulomb barrier. As a result, we can note the prospects of applying (γ, αn)-reaction on 94Mo to produce the 89Zr promise medical radionuclide isotope using electron accelerators.

Determination of the long-lived 10Be in construction materials of nuclear power plants using photoactivation method.

The problem of handling nuclear power plant irradiated structural materials holds one of the central places in the nuclear power industry. High toxic 10Be with a half-life of T1/2 = 1.6 × 106 years is discovered in NPP structural materials after reactor operating. 10Be decays through only electrons' emission. Pure beta emitters are extremely difficult to determine in irradiated structural materials and radioactive waste. We proposed a photoactivation approach for determining the 10Be activity in NPP samples. The proposed method involves determining 9Be and 10B concentrations and subsequent recalculation of 10Be activity formed in 9Be(n, γ)10Be and 10B(n, p)10Be reactions. The amount of 9Be and 10B is determined by samples' photoactivation using an electron accelerator and 9Be(γ, 2n)7Be-, 10B(γ, p2n)7Be-reactions. These reactions' experimental yields were measured for 20, 40, and 55 MeV boundary energies of the bremsstrahlung beam. The proposed technique was tested on samples of ChNPP 2nd unit irradiated structural materials. The technique's calculated error is about 15-20%; the sensitivity is 1 Bq × g-1.

[Role of Radionuclide Technologies in Medicine].

The paper describes the role of radionuclide technologies among the nuclear-physical methods used in medicine. The condition and prospects of the development of nuclear technology with use of radionuclides in medicine, and in particular, the method of brachytherapy are analyzed. The analysis of the current state of applying radionuclide facilities in medicine is provided.