Volodymir Yu. Bazhenov

This is a brief review of the current status of study and progress in devices for a new generation of plasma-dynamic tools based on combining a vacuum-arc plasma source with an axially symmetric cylindrical electrostatic plasma-optical lens into a single device. The combined system operates using the basic plasma-optical principles of magnetic electron isolation and equipotentialization along magnetic field lines and could be attractive for many practical applications of high current, moderate energy plasma sources of heavy metal ions and electrons. The hardware is relevant to processing equipment using dense cleaned plasma streams for the synthesis of coatings and thin films with given functional properties. A combination of the plasma lens with vacuum-arc ion plasma sources like the MEVVA allows control of low-energy dense plasma flow from the cathode spot region toward the substrate (for film deposition) or toward an extraction system (for ion beam generation). The application of the plasma lens for the transport of low-energy plasma is shown to improve plasma delivery to a substrate and provide microdroplet evaporation and elimination by fast electrons within the lens region. These results open up a new and attractive way for further development and application of erosion plasma sources for the synthesis of functional coatings, as well as for the creation of upgraded vacuum-arc ion sources with improved characteristics.

Recent developments of novel plasma-optical systems are described. For the first time, a combined system including a MEVVA plasma source with a cylindrical electrostatic plasma-optical lens is considered. This combined system is of fundamental interest and could be attractive for a number of practical applications. The system can be used for effective repetitively pulsed, high current, moderate energy plasma sources of heavy metal ions and electrons. The hardware is interesting for high productivity technological equipment using relatively pure plasma flow for the synthesis of fine coatings and thin films. We have studied the plasma-dynamic characteristics of high density plasma flow propagating through the plasma lens, the optical spectra and the charge state distribution, as a function of different experimental conditions. Application of the plasma lens to the transport of low energy high-current ion beams can improve the delivery of plasma to a substrate, as well as providing micro-droplet evaporation and elimination due to the presence of fast electrons within the lens region. Here mainly the transport aspects, as well as the effect of fast electrons on the characteristics of low energy ion plasma beams are considered.

Operation characteristics of RF planar barrier discharge in atmospheric pressure argon appropriate for obtaining the discharge extension outside the electrodes in a form of planar plasma jet are determined experimentally. The plasma jet images and spatial distributions of its light emission intensity are presented, and their features are discussed. The prospects of studied jet discharge for creation of liquid crystal alignment and etching polymer materials are demonstrated.

We report the results of an experimental study of synthetic opal composed from silica spherical particles. Immersion spectroscopy methods were used to inspect the "photonic forbidden zone" and the peculiarities of Bragg reflection in the material. A temporal response of luminescence from artificial opal excited by nitrogen laser UV pulses at room and liquid-nitrogen temperatures was examined. The afterglow with the decay time to about 1 second was found to appear at about 135 K. The temperature dependence of luminescence is of importance for explanation of the surprising effects of stimulated emission in a single nano-sized SiO₂ globule and second harmonic generation in the material under high-power excitation from Ti:Sapphire femtosecond laser.

Characteristics of planar barrier radio frequency (RF) discharge in different modes at atmospheric pressure of Ar have been studied experimentally and theoretically. Experimental data, as well as results of numeric simulation, have shown a presence of transient mode of the discharge glow, which is due to coexistence of low-current α and high-current γ discharge modes with occurrence of a transition between the modes during each half cycle of RF voltage supplied to the discharge.