V. Ya. Pecherkin

Confinement of the charged microparticles by alternating electric fields in a gas flow

This paper presents the simulation and experimental results of charged microparticles dynamics in electrodynamic traps in a gas flow at atmospheric pressure. For the first time the capture and confinement of charged microparticles in a linear Paul trap has been experimentally confirmed at atmospheric pressure in gas flows. The regions of the microparticle, linear Paul trap and gas flow parameters needed for microparticle confinement have been obtained and experimentally tested.

Capture and retention of charged dust particles in electrodynamic traps

The conditions of capture and retention of charged dust particles in linear Paul traps in air at atmospheric pressure in a wide range of parameters characterizing both dynamic traps and confined particles have been found by means of Brownian dynamics. It is shown that the viscosity of a gaseous medium strongly affects capture and retention of dust particles. The simulation results are in agreement with the experimental data on the creation and retention of a stable Coulomb cluster of charged dust particles in a quadrupole trap.

Nonlinear Impulse Current Spreading and Electrical Breakdown in Soil

The results of laboratory experiments on the impulse current spreading from the spherical electrodes and the breakdown occurring in quartz sand of various humidity at the impulse voltages of 20–40 kV are presented. It is shown that, at the current densities on the electrode above some critical value, a sharp nonlinear decrease of the impulse grounding resistance occurs, an ionization-superheating instability develops, and thus the current contraction takes place and a plasma channel in the soil occurs. A method is proposed to determine the critical strength of the ionization electric field. It was discovered that, at long discharge gaps in humid sand, the breakdown develops with a long time delay, similarly to thermal breakdown.

Investigation of the effect of a protective layer on parameters of quartz low-pressure gas-discharge lamps with oxide electrodes

Low pressure amalgam lamps are widely used for disinfection of air and water surfaces. The application of amalgam instead of pure mercury makes it possible to design a high-efficiency powerful ultraviolet lamp and to improve the ecological impact of disinfection equipment. This paper describes the effect of oxide electrodes and a quartz inner surface on the lifetime of a lamp and on the ultraviolet-intensity reduction in low pressure lamps. We show that the burning time of the noble-gas arc discharge at a low pressure depends on the interaction between the discharge plasma and the inner quartz surface. Use of a rare-earth-metal-oxide protective layer on the inner quartz surface increases the lifetime of the lamp and prevents ultraviolet-intensity reduction in low-pressure amalgam lamps.

Electric breakdown during the pulsed current spreading in the sand

Processes of spreading of the pulsed current from spherical electrodes and an electric breakdown in the quartz sand are studied experimentally. When the current density on the electrode exceeds the critical value, a nonlinear reduction occurs in the grounding resistance as a result of sparking in the soil. The critical electric field strengths for ionization and breakdown are determined. The ionization-overheating instability is shown to develop on the electrode, which leads to the current contraction and formation of plasma channels.

Spark channel propagation in a microbubble liquid

Experimental study on the development of the spark channel from the anode needle under pulsed electrical breakdown of isopropyl alcohol solution in water with air microbubbles has been performed. The presence of the microbubbles increases the velocity of the spark channel propagation and increases the current in the discharge gap circuit. The observed rate of spark channel propagation in microbubble liquid ranges from 4 to 12 m/s, indicating the thermal mechanism of the spark channel development in a microbubble liquid.

Optical investigations of pulsed sparks in soil near electrode

Experimental results of laboratory investigation of nonlinear processes in moist soil near electrode simulating grounding of electric power facilities are presented. A method of optical recording of spark formation in the soil is developed. Investigations were carried out at voltage of 20-50 kV and current pulse duration of tens of microseconds. The critical electric field and delay of sparks beginning in soil in depending on the electrode construction, moisture and impulse duration are obtained. The images of sparks in soil are obtained for the first time.

Temperature effect on the burning time of a low-pressure discharge in a quartz discharge tube with a protective layer

It is shown that an increase in the temperature of a quartz discharge tube with a protective layer of rare earth metal oxides on the inner surface leads to a decrease in the burning time of a low-pressure arc discharge in inert gases. In this case, the dominant mechanism that leads to a decrease in the burning time is the loss of electron emission because of the complete sputtering of the emitting material of the oxide electrodes.

Experimental investigation of a low-pressure amalgam lamp at an increased power of discharge

Low-pressure discharges in a mixture of mercury vapor with inert gases are widely used in engineering. This is due to a high (up to 80%) efficiency of the conversion of electric energy to radiation of two resonance lines of mercury atoms [1, 2]. The radiation sources with a discharge of this type may be used for disinfection, because the radiation of a line with a wavelength of 253.7 nm (63P1--61S 0 transition) proves to be lethal for microorganisms.

Charging of Macroparticles in a Corona Discharge in an Air Flow

The charging of Al2O3 macroparticles with dimensions ranging from 20 to 40 μm in a gas flow passing through a multielectrode corona discharge is investigated. The corona discharge is produced by a system of wire electrodes arranged across the gas flow. The particle charge and mass are measured using a linear electrodynamic trap. For a corona voltage of 18 kV, the average charge-to-mass ratio is found to be 1.69 × 1013e/g for particles charged in the positive corona and 1.35 × 1013e/g for particles charged in the negative corona.