The experimental results of complex investigations of the high-current self-sustained glow discharge in helium at atmospheric lressure are presented. The studied discharge was produced in the current range 005 — 15 A. The electrical discharge power had been reached up to 3.5 kW. The different diagnostic methods are used: an electric probe, a tlurmopair, a laser, emission spectroscopy. The electric field strength, gas temperature, electron density and metastable helium atoms density are mapped. The obtained results are discussed with attraction of the existing theory of the cathode fall region taking into account the volumetric heat-evolution.

High-pressure discharges are generated using Micro-Structured Electrode (MSE) arrays with electrode distances between 50 and 250 µm. These arrays consist either of a planar electrode system bonded to a dielectric substrate or of a matrix of holes perforated in a composite sheet made out of two metallic foils separated by an insulator. Stable discharges were produced for pressures ranging from 10 to 1000 mbar using DC and radio frequency excitation. The optical appearance is that of a homogeneous glow discharge. Spectral investigations have revealed the presence of a large number density of metastable atoms and highly energetic electrons, while the discharge has a non-thermal character. The non-equilibrium high -pressure plasma provided by the MSE arrays is suitable for surface activation, thin film deposition and reduction of pollutants.

It is common, diffusive glow regime of steady-state positive corona is followed by streamer regime with increase in overage corona current. The coefficient of ionization multiplication of electron avalanche over interelectrode gap in glow corona is less than that is necessary for the avalanch-to-streamer transition. Under such conditions, a local development of ionization instability nearby the sharpened electrode plays crucial role in initiation of mild streamers in glow corona. Indeed using a fast frame camera we have revealed on electrode the occurrence of small high-density current spots, which provoked the mild streamer in glow corona. A transient behavior of these streamers followed by spark was examined in detail for a positive pin-plane corona in pure nitrogen and ambient air at atmospheric pressure. It was observed that scenarios for the streamers-to-spark transition in air and N2 differed essentially from each other.

Excitation pulse form and power and some other discharge parameters influence on barrier discharge KrC1 excilamp efficiency was studied in present paper. It is shown that at barrier KrC1 excilamp excitation by short (2÷2,5 µs) unipolar or bipolar voltage pulses the efficiency is higher than by sine pulses excitation. Presence of filaments occurs to be a necessary condition to obtain high efficiency since in that case a demanded level of excitation specific power is being achieved. Radiation pulse delay relatively to excitation in the conditions of homogeneous discharge probably demonstrates low efficiency of KrCl* molecules formation at a low level of excitation power.

Carbon dioxide decomposition in a non-self-sustained discharge was studied by the methods of diode laser spectroscopy and mass-spectrometry. It was show that the effective control of the mechanism of a plamachemical reaction is possible by varying the parameter E/N. This allowed us to reduce the energy cost of dissociation CO2 by more than on an order of magnitude as compared to the dissociation process in a self-sustained glow discharge.

The plasma focus discharge is discussed as a source of intensive x-ray radiation. This radiation is observed in two different regimes of compression —the "filamentary" and the "hot point" types. A typical parameters of radiating pinch are presented and the role of the energetic electron beam on the spectral image is discussed. The presented results of 2D image spectrometry demonstrate detailed space structures of radiating plasma. All the experiments were performed on the installations "TULIP" (FIAN, Moscow) and PF-1000 (IPPiLM, Warsaw).

Spectroscopy of pulsed nonequilibrium plasma allows to control behaviour of active particles in situ, that is with subnanosecond temporal and high spatial resolution. Present work demonstrates advantages of emission optical spectroscopy as applied to kinetic description of pulse-periodic discharges at high overvoltages in the pressure range 0.1-30 Torr and at atmospheric pressure. Features in common and distinction in experimental observation of such discharges are discussed. Measurements of velocity of the discharge propagation, reduced electric field behaviour and number density of excited particles are represented for a wide range of experimental conditions.

The production and loss kinetics of CF2 and CF radicals in the CF4 glow discharge were studied with using the time— resolved LIF technique. The effective rate constants of the CF4 dissociation into the chanhels with CF2 and CF production were determined in a wide range of reduced electric field: 80-250 Td. It is shown that besides of the CF4 dissociation by direct electron impact there is also another source conditioned by fluorocarbon plasma polymerization processes. The detailed analysis of growth and decay dynamics of radical concentrations at the discharge modulation has allowed us to separate different channels of the radical production and consequently to determine the constants of CF4 dissociation rate by electron impact KCF2 KCF and A comparison of received KCF2 and KCF with calculations made on the base of solving the Boltzman equation by Monte-Carlo technique with using the available data on electron scattering cross-sections on CF4 molecules, has in part allowed us to renormalize the partial dissociation cross-sections near the threshold and to build up the model cross-sections of neutral dissociation of CF4 by electron impact It is shown, that the polymerization processes substantially contribute (particularly at low values of E/N) to production of radicals, as in a plasma volume, and on a surface of the discharge tube. The analysis of the obtained data on characteristic frequencies (times) of these processes has allowed us to study mechanisms of fluorocarbon's polymerization in CF4 plasma in conditions of high relative concentration of fluorine atoms and low ion energy. So it is shown, that with increasing pressure, when the concentration of polymer fragments CxFy in bulk of plasma is comparable with concentration of simple fluorocarbon radicals CFx (x=1-3), the dissociation of these fragments by electronic impact and the reactions of unsaturated fluorocarbon fragments CnF2m+1 as in volume, and on a surface of a fluorocarbon film, covering discharge tube walls become the main production channels of CF2 and CF. Since with lowering pressure a major channel of CF2 and CF destruction is connected with their heterogeneous losses on tube walls, the surface loss probabilities of CF2 and CF radicals in conditions of the fluorinated fluorocarbon film surface are determined. It is shown, that the most probable mechanism of heterogeneous loss of CF2 and CF under these conditions is the surface recombination of chemisorbed fluorine atoms Fch and physadsorbed radicals CFxPh (x=1-2) through the formation of an activated surface complex. The analysis of the experimental data with using this approach has allowed us to estimate the approximate values of activation energies for the formation of the surface complexes Fch. CF2ph and Fh. CFPh - 750 ± 70 K and 1030 ± 100 K respectively.

Dynamics of light emission for the N2(A 3?+u), N2(B 3?g) and N2(C3?u) electronic excited states was studied spectroscopically in a long pulse glow discharge in pure nitrogen and in afterglow at pressure 50 Torn An appropriate mathematical processing was made to derive population of excited states from these measurements A rather complete kinetic model was developed for conditions ofthe experiments. Results ofcomparison are analyzed.

In this work we discuss some physical aspects of surface wave driven discharges operating in pure nitrogen N2 and in N2—Ar mixtures, as sources of active species. The developed theoretical models are based on a self-consistent treatment of particle kinetics, wave electrodynamics, gas thermal balance and plasma-wall interactions. By means of optical emission and absorption spectroscopy the population density of the species of interest has been detected. Important problems concerning inhomogeneous wave—to—plasma power transfer, mechanisms of N2 dissociation, creation of ions and metastable particles are discussed in the terms ofthe obtained theoretical and experimental results.

The possibility is considered of restoring the electron energy distribution function (EEDF) in the interval of electron energies 0 < e < 5 eV from measurements of translational and vibrational temperatures by the coherent anti-Stokes Raman scattering (CARS) method in a positive column of a glow discharge in molecular nitrogen at 20