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Using the method of evaporation by pulsed electron beam in vacuum the mesoporous nanopowder of CaF 2 with a specific surface area up to 91.5 m2/g was produced. The effect of annealing in different media and irradiation with a nanosecond electron beam (700 keV) on the evolution of the magnetic, luminescent and textural properties of CaF 2 nanoparticles have been studied. For the first time, a joint effect of the annealing medium and the absorbed dose of a relativistic electron beam irradiation on the specific surface area and magnetization of mesoporous nanopowders of the CaF 2 was discovered, which confirms the defective nature of ferromagnetism at room temperature of CaF 2 nanopowders. The effect of nanopowder surface properties on ferromagnetism at room temperature after annealing in different media is shown, a parameter for assessing this influence is proposed. It was found that annealing and irradiation caused a significant change only in the visible range, of the pulse cathodoluminescence spectra of the CaF 2 nanopowder, with the temperature and medium of the nanopowder pre-annealing as well as the irradiation dose being important. The relationship between luminescent and magnetic properties of nanopowder was shown. [ABSTRACT FROM AUTHOR]

Using vacuum evaporation by a pulsed electron beam, mesoporous CaF2 nanopowders with a specific surface area of up to 91.5 m2/g were obtained. The effect of nanosecond electron beam irradiation in air on the magnetic and texture properties of the obtained nanopowders was studied. For the first time, the effect of irradiation on the specific surface and magnetization of CaF2 nanopowders was revealed. [ABSTRACT FROM AUTHOR]

Methods for the synthesis of new chelating chitosan derivatives containing 2-carboxyethyl groups were developed. Their macromolecules were cross-linked by the irradiation with a nanosecond electron beam, which gave for the first time sorbents with a high sorption capacity for CuII ions. The maximum sorption capacity, which is achieved in the pH range 6.5–7.2. and the Langmuir adsorption constant of Cu2+ ions on the sorbent with the degree of substitution 0.91 are 1.37 mmol g−1 and 152.51 L mol−1, respectively. The structures of the formed complexes in the sorbent phase were characterized by ESR spectroscopy. [ABSTRACT FROM AUTHOR]

The development of radiation processing methods for food and agricultural products increases the demand for methods of control over the processing and circulation of products. ESR spectrometry is a promising method for monitoring and detecting, which is already being used to control products containing bones, cellulose and crystalline sugar. This research presents the results of a study of the radiation-induced ESR signal in eggshells and the kinetics of radicals over time. The samples were irradiated using the URT-0.5 (0.5 MeV) and UELR-10-10S2 (10 MeV) electron accelerators. The ESR signal spectra were obtained on an ELEXSYSE500 ESR spectrometer. The dependencies of the ESR signal intensity on the value of the absorbed dose were obtained, and a comparative analysis of the irradiation of chicken eggs with different energies was carried out. • The samples were irradiated using the URT-0.5 (0.5 MeV) and UELR-10-10S2 (10 MeV) electron accelerators. • ESR signal was measured at ELEXSYSE500 ESR spectrometer. • The dependences of the ESR signal intensity on the absorbed dose in eggshell were obtained in the range from 1 to 40 kGy. [ABSTRACT FROM AUTHOR]

A vacuum diode for the two-sided electron irradiation of objects makes it possible to reduce the irradiation nonuniformity and increase the thickness of the irradiated layer of the object with a uniform distribution of the absorbed dose over the layer thickness. The cathode holder of the diode is constructed in the form of two symmetrical arms connected to a common current lead. Two cathodes are attached to the arms' ends opposite each other. The electron beam is extracted to the atmosphere through two windows–anodes positioned across from one another. The vacuum diode with metal–dielectric cathodes was tested on a УРТ-0.5 nanosecond electron accelerator (the electron energy is ∼0.5 MeV and the output beam power is ∼1 kW). The results obtained have shown that the diode ensures the two-sided irradiation of objects. Depending on the irradiated surface, the irradiation conditions can be varied by changing the cathode–anode distance in one of the arms of the diode. [ABSTRACT FROM AUTHOR]

Magnetic nanopowders of oxides Al 2 O 3 , SiO 2 , CeO 2 and YSZ (ZrO 2 -8% Y 2 O 3 ) with a high specific surface area irradiated in air by electrons with energy of 700 keV, pulse duration 100 ns, using the repetitively pulsed accelerator URT-1 within 15 and 30 min. The magnetic, thermal, and cathode luminescence characteristics of NPs were measured before and after irradiation. It was established that the electron irradiation non-monotonically changes the magnetization of the pristine samples. On the contrary, a clear correlation between the intensity of cathode luminescence and the irradiation dose is found in the most of the oxides. Thermal stability and phase transformations of unirradiated and irradiated CeO 2 and YSZ oxides were analyzed with the aid of synchronous analysis, using the methods of thermogravimetry and differential scanning calorimetry. The luminescent and thermal properties reflect the transformation of structural defects in NPs more strongly after exposure to a pulsed electron beam in comparison with corresponding changes of the NP's magnetic response. [ABSTRACT FROM AUTHOR]