A.A. Trenkin - Ph.D. (Phys.-Math.), Associate Professor, Head of Department of Experimental Physics, Sarov Physical and Technical Institute of NRNU MEPhI; State Corporation of Atomic Energy «Rosatom» Federal State Unitary Entity «Russian Federal Nuclear Center - All-Russia Scientific and Research Institute of Experimental Physics» (Sarov, Nizhny Novgorod region) E-mail: trenkin@ntc.vniief.ru V.I. Karelin - Dr.Sc. (Phys.-Math.), Head of Research Division, State Corporation of Atomic Energy «Rosatom» Federal State Unitary Entity «Russian Federal Nuclear Center - All-Russia Scientific and Research Institute of Experimental Physics» (Sarov, Nizhny Novgorod region) E-mail: karelin@ntc.vniief.ru V.D. Beibalaev - Ph.D. (Phys.-Math.), Associate Professor, Department of Applied Mathematics, Dagestan State University (Makhachkala) E-mail: kaspij_03@mail.ru Z.Z. Alisultanov - Ph.D. (Phys.-Math.), Associate Professor, Department of Theoretical and Mathematical Physics, Dagestan State University; Senior Research Scientist, Amirkhanov Institute of Physics Russian Academy of Sciences, Dagestan Science Centr (Makhachkala) E-mail: zaur0102@gmail.com G.B. Ragimkhanov - Ph.D. (Phys.-Math.), Associate Professor, Associate Professor, Department of Physical Electronics; Senior Research Scientist, Scientific Research Laboratory of Plasma Physics, Dagestan State University (Makhachkala) E-mail: gb-r@mail.ru

This paper describes a phenomenon of high-energy electron fluxes generation in microstructured nanosecond diffusive discharges. The phenomenon is considered in the frameworks of an earlier developed model of the electrons acceleration in the branching systems of the gas-discharge channels. According to this model, the spatial structure of such discharges is formed on the stage of the discharge gap bridging at the expense of ionization instability. In the result, self-organization of the branching channel structure with sequentially decreasing channel diameters takes place. In this case, imprints of the channels of micron diameter were recorded on the electrodes surface in some experimental works. Conductivity current flow causes heating and radial expansion of the channels. In the result of this, gas concentration and, consequently, frequency of the electron collisions with neutrals, are decreasing. This provides the conditions for generation of the high-energy electrons fluxes and bremsstrahlung. Based on the results of the previously performed works, the authors note expediency of fractional integro-differentiation application at description of the charged particles transfer processes in collision channel systems. To describe the dynamics of the electrons transfer in the discharge channels with variable gas concentration, this paper proposes nonlinear differential equation of fraction order. It is shown that the collision frequency of electrons with neutrals is inversely proportional to the electron path, when there is no significant change of specific electric resistance of the channel. Generalized regime of the electrons motion, which describes the transition from the drift motion to uniformly accelerated one, was obtained in the result of the equation solution. At collisions, the electrons run shorter path before the beginning of uniformly accelerated motion, when the portion of the energy loss increases; their velocity during motion increases slower. The calculations showed that the electrons velocity decreases, when the fractal dimension of the spatial structure of the gas-discharge channels also decreases. This dependence could be interpreted as increase of the dissipative effect in the points of the channels branching. Values of the energy accumulated by the electrons on the discharge gap length are calculated; their satisfactory agreement with the experimental results is shown. Restrictions of applicability of the description, presented in this paper, are determined. They are associated with the electrons motions duration in the channels and consideration of the relativistic effects. It is shown that the results obtained in this paper do not go beyond the bounds of these restrictions.

 

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