Open Access
Access granted
Subscription Access
Vol 44, No 5 (2017)
- Year: 2017
- Articles: 7
- URL: https://journal-vniispk.ru/1068-3356/issue/view/14101
Article
123-126
Detector for visualizing the absorbed dose formation region in a water phantom exposed to an electron beam for biological experiments
Abstract
A detector with a highly sensitive television camera for visualizing the absorbed dose formation region in a water phantom is developed and tested at the electron beam of the “Pakhra” accelerator. The detector consists of a water phantom and a television camera with equipment for picking-up information from it. The geometrical shape and sizes of the luminosity region in the phantom exposed to a pulsed electron beam with an energy of 7 MeV are determined. Model calculations for determining absorbed doses upon electron absorption in water are performed.
127-129
Study of the coordinate prediction accuracy for galactic particles with an energy of 10–1000 TeV/particle using a new method for searching and tracking particles in nuclear emulsion films. (Data of the Russia–Nippon Joint Balloon (RUNJOB) experiment)
Abstract
Experimental and methodological errors in the coordinate prediction for primary cosmic ray nucleons and nuclei in nuclear emulsions using a new method for searching and tracing particle tracks in emulsion films of X-ray emulsion chambers (XRECs) exposed in the stratosphere in the Russia–Nippon Joint Balloon (RUNJOB) experiment are considered in detail. The dependence of errors on the relation between angular characteristics of the sought particle and auxiliary multiply charged nuclei is analyzed. Angular selection criteria for auxiliary nuclei, at which the methodological error of the particle track coordinate prediction decreases, are found.
130-136
Separation of calcium and magnesium solvated cations under the action of external periodic electric field on moving solution
Abstract
The experimental results on the excitation of the phenomenon of selective drift of solvated ions under the action of an external “asymmetric” electric field on a circulating solution of calcium and magnesium chloride salts in polar liquid dielectric, i.e., in water, are presented. The objective of the experiments was the determination of the features of the effect of the field frequency and field strength amplitude on the phenomenon excitation, and the study of operating characteristics of the experimental device, i.e., the separation cell. The dependences of the efficiency of solvated cation separation on the external field frequency and the phenomenon excitation threshold in the field strength in the separation cell are determined.
137-142
Study of the “metal–insulator” transition induced by the impurity fluctuation potential using the Shubnikov–de Haas effect
Abstract
Heterostructures with a GaAs/InGaAs/GaAs quantum well and aMn magnetic impurity layer separated from it, which have different conductivity types, are studied. At a Mn content not exceeding the amount corresponding to 0.5 monolayer of MnAs, a percolation cluster formed in the quantum well plane is not simply connected, but consists of metal drops separated by low-conductivity interspaces. Despite the absence of the simply connected conducting channel, Shubnikov–de Haas oscillations are observed in all studied systems, which are controlled by carrier properties in conducting drops, independent of Mn content. The estimate of drop sizes corresponds to theoretical values.
143-146
Study of the glow discharge in inert gases with water vapor
Abstract
The behavior of the water vapor concentrations and fragments in wet plasma is studied. The results of plasma-chemical modeling are compared with the results of direct measurements of water molecule dissociation in plasma.
147-150
Computer simulation of edge-terminated carbon nanoribbons
Abstract
In this paper, we present the results of ab initio simulation of edge-terminated carbon nanoribbons (CNRs). The calculations were performed using the electron density functional theory with the expansion of electron wave functions in plane waves in the Quantum Espresso software package [1]. The effect of various edge termination types on the band structure of graphene nanoribbons is studied. The data obtained showed that hydrogen and fluorine termination has a very weak effect on the structure. Sulfur or bromine termination causes a semiconductor-to-metal transition. The cause of the change in the conductivity type is the appearance of the electron dispersion curve crossing the nanoribbon band gap. At the same time, the dispersion dependences of the ribbon edge-terminated with alternating chlorine and hydrogen atoms do not exhibit such a change, and the curve mentioned above is not observed. The causes of the observed effects are analyzed.
151-153