Scaling of DD fusion power in a nanosecond vacuum discharge

Earlier, in a nanosecond vacuum discharge (NVD) with a deuterated Pd anode, the appearance of DD neutrons was observed not only at the well-studied quasi-stationary stage, where a virtual cathode (VC) appears in the interelectrode space, but also at the very initial stage of the discharge. An analysis of the experiment shows that the autoelectron beam can play the role of a kind of trigger for starting DD syntheses processes on the surface or in the bulk of the Pd anode, but its mechanism at the initial stage of the discharge remained unclear. In this work, we performed PiC modeling of the possible partial penetration of a beam of autoelectrons into hollow anode Pd tubes. This leads to the formation of very small short-lived VCs inside individual Pd tubes, where, starting from a current of 100 A, DD microsynthesis is possible. It is shown that in devices with oscillating ions the favorable scaling of the DD fusion power, which increases with decreasing VC radius, can be retained up to rVC  0.02 cm.

The Electrodynamic Mechanism of Collisionless Multicomponent Plasma Expansion in Vacuum Discharges: From Estimates to Kinetic Theory

This paper is devoted to the study of collisionless multicomponent plasma expansion in vacuum discharges. Based on the fundamental principles of physical kinetics formulated for vacuum discharge plasma, an answer is given to the following question: What is the main mechanism of cathode plasma transport from cathode to anode, which ensures non-thermal metallic positive ion movement? Theoretical modeling is provided based on the Vlasov–Poisson system of equations for a current flow in a planar vacuum discharge gap. It was shown that the non-thermal plasma expansion is of a purely electrodynamic nature, caused by the formation of a “potential hump” in the interelectrode space and its subsequent movement under certain conditions consistent with plasma electrodynamic transportation. The presented results reveal two cases of the described phenomenon: (1) the dynamics of single-component cathode plasma and (2) multicomponent plasma (consisting of multiple charged ions) expansion.

Calculation, simulation and study of the process of electrochemical deposition of microsphere films

The paper presents the results of the calculation of the main parameters of electrochemical deposition of microsphere films from a colloidal solution. Within the research, we determined the factors affecting the rate of their growth. The study shows the results of mathematical simulation of the process, characterizing the change in the potential in the interelectrode space, as well as the results of experimental studies of the formation of microsphere structures. Findings of the research were used to estimate the uniformity of the formed structures according to the reflection coefficient. For this purpose we applied the method of full factorial experiment. The study shows that the uniformity of the structures deteriorates with increasing potential difference and pH of the solution. It was also found that with an increase in the process time, the thickness of the structure increases, while the uniformity and ordering decrease. Findings of the research can be used in the further formation of 3D nanocomposites for various applications, for example, to increase the magnetic recording density

Modeling of formation of carbon cluster groups in electric arc discharge plasma

The problem of modeling complex resource-intensive processes of plasma synthesis of carbon nanostructures (CNS) on the basis of mathematical and numerical methods of solution, focused on the use of parallel and distributed computing for processing large amounts of data, allowing to investigate the relationship and characteristics of processes to obtain an effective, cost-effective method of synthesis of CNS (fullerenes, nanotubes), is an actual theoretical and practical problem. This article deals with the problem of mathematical modeling of motion and interaction of charged particles in a multicomponent plasma based on the Boltzmann equation for the synthesis of ONS by thermal sublimation of graphite. The derivation of the collision integral is presented allowing to perform a numerical solution of the Boltzmann - Maxwell equations system with respect to the arc synthesis of CNS. The high order of particles and the number of their interactions involved simultaneously in the process of synthesis of CNS requires significant costs of machine resources and time to perform numerical calculations on the constructed model. Application of the large particle method makes it possible to reduce the amount of computing and hardware requirements without affecting the accuracy of numerical calculations. The use of parallel computing technology on the CPU and GPU with the use of Nvidia CUDA technology allows you to organize all the General-purpose calculations for the developed model based on the graphics processor of the personal computer graphics card, without the use of supercomputers or computing clusters. The results of experimental studies and numerical calculations confirming the adequacy of the developed model are presented. Obtained quantitative characteristics of the total pairwise interactions between the carbon particles and interactions with the formation of clusters of carbon with various types of ties in the plasma of the interelectrode space which are the basis of the synthesized nanostructures. The formation of carbon clusters occurs in the entire interelectrode space of the plasma with different intensity and depends on the process parameters.

Modeling of process of copying of a ledge form on an electrode-tool at electrochemical machining

Problems of modeling of a non-stationary electrochemical shaping are reduced to the solution of two boundary problems for definition of analytical functions of the complex variable: conformal mapping of the parametrical plane on physical and partial derivatives on time of interelectrode space points coordinates. Each of functions is obtained in the form of the sum of known function with singularities and two unknown functions defined by Schwartz or Keldysh – Sedov's formulas. One of unknown functions is intended for the description of a form of an electrode-tool, the second – the processed surface. Results of the numerical solution of problems with an electrode in the form of a circle and a plate are presented.