Results of operating LIA-2 in radiograph mode

The LIA-2 linear induction accelerator was developed at the Budker Institute of Nuclear Physics as an electron beam injector for a building induction accelerator at energy of 20 MeV, on the basis of which a complex for flash radiography will be developed. The LIA-2, which was started up in 2010, is currently used as an independent X-ray unit for raying objects with an optic thickness up to 70 mm in the lead equivalent. The effective diameter of the X-ray source is 0.6–0.7 mm.     

Implantation of helium and deuterium ions into tungsten-coated composite structures

Various processes occurring in tungsten coatings deposited on composite substrates under ion irradiation have been analyzed. Processes leading to formation of radiation defects of a crystal lattice, helium and deuterium accumulation, and their thermodesorption from samples are compared. Possible mechanisms behind these processes are discussed.     

Condensed imidazo-1,2,4-azines. 14. Synthesis and reactivity of 3-chlorine-substituted imidazo[1,2-b]-1,2,4-triazines

When boiled with phosphorus pentachloride in phosphorus oxychloride, 2-methyl-6-phenyl-imidazo[1,2-b]1,2,4-triazin-4H-3-one gives a mixture of mono- and dichloro derivatives, whereas the action of thionyl chloride in chloroform with a catalytic amount of DMFA gives only the monosubstituted product 2-methyl-3-chloro-6-phenylimidazo[1,2-b]-1,2,4-triazine. The reactivity of the 3-chloro derivatives of imidazo[1,2-b]-1,2,4-triazine in reactions with diethylamine, piperidine, morpholine, aniline, hydrazine hydrate and thiourea was investigated.For Communication 13, see [1].Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 981–985, July, 1986.     

PAMELA spectrometer data processing

The international space experiment PAMELA was started in the mid-2006 and was finished in the beginning of 2016. The main objective of the experiment was the study of the cosmic ray spectra and elemental composition (including antiproton and positron spectra) in a wide energy range. The main instrument of the PAMELA device is a spectrometer including several detectors. Since the case in point here is the technique of processing the results for high-energy particles (protons, α-particles with energies E ≥ 50 GeV/nucleon, electrons and positrons with E ≥ 50 GeV), the three detectors were mostly used in data processing: a tracker placed into a dc magnetic field, a calorimeter, and a neutron detector. A relatively simple technique for separating electrons and positrons from the total flux of charged particles arriving at the spectrometer and a technique for determining the energy of these particles and constructing their energy spectra are described. This paper is based on the results presented in [1].     

Ion-implanted deuterium accumulation in a deposited tungsten coating

The effects of trapping of ion-implanted deuterium and its thermal desorption on the structure and stressed state of a tungsten coating deposited on a composite substrate is studied. The amount of accumulated deuterium, macrostresses of the coating, and the shape of thermal desorption spectra are shown to depend on the D⁺ ion fluence and the irradiation temperature. Possible mechanisms of these processes are proposed.     

Ion abundances of low-energy quiet period particle fluxes at 1 AU

The ion abundances of charged particle fluxes with energies of 0.032–1.28 MeV/nucleon during the quiet period of solar activity are investigated using spacecraft data. The values of Fe/O ratios obtained in 35 such periods in the 23rd solar cycle are compared with the mean ion abundances in the solar corona, in the gradual and impulsive solar energetic particle events, and in the solar wind. It is believed that coronal holes near the equator could be one of possible source of background low energy particle fluxes.     

Registering Jovian electrons in the Earth’s orbit

The results from observing Jovian electrons in the vicinity of the Earth are discussed. Variations in Jovian electron flows are observed during 14 rotations of the Sun in 2007–2008. The results are analyzed by assuming the existence of magnetic traps in the space between the Sun and Jupiter that are filled with electrons near Jupiter, and are then registered when the traps pass by the Earth. The average period of variation in the Jovian electron flow during the 14 solar rotations is 26.2 days instead of the expected synodic period of the Sun–Earth system equal to 27.3 days. An explanation for this phenomenon is proposed.     

Study of the electronic structure and properties of 13C-isotope-based composites

The morphology and electronic structure of ¹³C-isotope-based graphite composites were studied by transmission electron microscopy (TEM), x-ray diffraction, and x-ray fluorescence spectroscopy. High-resolution TEM images showed that composites contain several forms of carbon particles. According to an x-ray diffraction analysis, the size of graphene stacks of graphite particles is 20 and 40 Å. The CK _α x-ray fluorescence spectra of the initial ¹³C isotope powder and composites based on it detected an increase in the density of high-energy occupied states in comparison with the graphite spectrum. Ab initio quantum chemical calculation of the structure of C₁₅₀ graphene showed that the increase in the density of states stems from the electrons of dangling bonds of boundary carbon atoms of particles ～20 Å in size. Electrical properties of ¹³C-isotope-based samples were studied by analyzing the temperature dependence of the conductivity. It was assumed that the change in the logarithmic dependence of the conductivity observed at liquid-helium temperatures to the linear dependence as the temperature increases is caused by carrier transfers between the disordered graphene layers forming a nanocomposite.     

Reactor target from metal chromium for “pure” high-intensive artificial neutrino source

The paper presents the first results of development of manufacturing technology of metallic chromium targets from highly enriched isotope ⁵⁰Cr for irradiation in a high flux nuclear reactor to obtain a compact high intensity neutrino source with low content of radionuclide impurities and minimum losses of enriched isotope. The main technological stages are the hydrolysis of chromyl fluoride, the electrochemical reduction of metallic chromium, the hot isostatic pressing of chromium powder and the electrical discharge machining of chromium bars. The technological stages of hot isostatic pressing of chromium powder and of electrical discharge machining of Cr rods have been tested.