The interest of electric propulsion for the orbit maintenance of geostationary telecommunication satellites is explained. The performances of different plasma sources are presented. Hall effect thrusters are described in detail and the Smart1 mission in space using a Hall thruster is briefly described.

Our plasma materials research has been a significant influence in developing microwave plasma enhanced chemical vapour deposition (MPECVD) of diamond and in a similar process for nanocrystalline silicon. These contrasting materials will be presented, together with techniques for determining their structure and quality, including X-ray Photoelectron Spectroscopy (XPS) and Raman Spectroscopy. For instance, Raman spectra clearly show the dependence on deposition parameters of the crystallinity of MPECVD Si films deposited at temperatures below 200$^{\circ}$C on to glass, aluminium and polyester. By using mixtures of silane with argon and/or hydrogen, these films are designed to have amorphous or nanocrystalline structure. Photosensitive P-I-N diodes have been produced on conductor-coated, polyester fabric as a step towards manufacturing flexible solar cells on textiles.
In contrast, the higher temperature synthesis of diamond and its unique properties (e.g. resistance to high heat flux and chemical erosion) has led to the first experiments on microcrystalline and nanocrystalline CVD diamond as a candidate coating for plasma-facing components in tokamaks. Our exposure results show that diamond coatings do not delaminate, undergo only slight surface amorphisation, retain only small amounts of deuterium in the surface and erode in hydrogen or deuterium plasma ~40% slower than graphite.

Test modes on turbulent magnetized plasmas are studied taking into account the ion trapping that characterizes the $\mathbf{E}\times \mathbf{B}$ drift in the background turbulence. We show that trapping provides the physical mechanism for the formation of large scale potential structures (inverse cascade) observed in drift turbulence. Trapping combined with the motion of the potential with the effective diamagnetic velocity determines ion flows in opposite directions, which reduce the growth rate and eventually damps the drift modes leading to intermittent evolution of turbulence.

In next generation magnetic fusion devices such as ITER, plasma-facing materials are exposed to unprecedented high ion, power and neutron fluxes. Those extreme conditions cannot be recreated in current fusion devices from the tokamak type. The plasma-surface interaction is still an area of great uncertainty. At FOM Rijnhuizen, linear plasma generators are used to investigate plasma-material interactions under high hydrogen ion flux-densities up to 10²⁵ m^-2s^-1 at low electron temperatures (≤ 10 eV), similar to the conditions expected in the divertor of ITER. The incident ion fluxes result in power fluxes of > 10 MW/m². A new linear plasma device, MAGNUM-PSI, is expected to begin regular plasma operations in the middle of 2011. This device can operate in steady-state with the use of a 3 T super-conducting magnet, and a plasma column diameter projected to 100 mm. In addition, experimental conditions can be varied over a wide range, such as different target materials, plasma temperatures, beam diameters, particle fluxes, inclination angles of target, background pressures, magnetic fields, etc. , making MAGNUM-PSI an excellent test bed for high heat flux components of future fusion reactors. Current research is performed on a smaller experiment, Pilot-PSI, which is limited to pulsed operation, a maximum magnetic field of 1.6 T and a narrow (~ 20 mm) column width. The research is primarily focused on carbon based materials and refractory metals. Erosion of materials, surface morphology changes as well as hydrogen implantation, diffusion and inventory in the materials are studied under fusion reactor conditions. The influence of neutron damages is studied by irradiation of the materials with high energy ions. A research programme addressing those before mentioned issues is presented.

In the article results of investigation of a reverse vortex hybrid plasma torch were described. The hybrid plasma torch is a combination of RF plasma torch and arc plasma torch. In this kind of torch reverse vortex gas stabilization was used to increase an efficiency of plasma energy. At the start operational mode arc plasma jet is used for the ignition of RF plasma. It was shown that hybrid plasma torch works successful with different plasma gases, and its characteristics is better than the arc plasma torch and RF one have shown each taken separately.

Experimental results are presented on plasma properties of a thermionic vacuum arc (TVA) produced in copper vapor. Plasma parameters as spatial distribution of the plasma potential and electron temperature were measured using emissive probe technique and double probe, respectively. The former parameter clearly shows presence of a strong double layer (DL) structure surrounding the anodic plasma, which separates low density plasma formed downstream within cathode region and high density plasma formed upstream in the anode region. The potential drop across DL is of the order of the anode potential (kV) so that kinetic energy gained by charged particles crossing DL is much larger than their initial thermal energy.

Time resolved tunable diode laser absorption spectroscopy (TD-LAS) on Al and metastable Ar atoms in High Power Pulsed Magnetron Sputtering was performed in order to study the time and space dependency of both species in the afterglow of pulsed plasma. In doing that synchronizing of the high power pulse frequency with the scanning frequency of the diode laser was necessary and performed.

In the last decade, advances in atmospheric pressure plasma technology allowed development of new many applications. Non-thermal plasma systems have been used for surface sterilization and functionalization, blood coagulation and more recently for tissular regeneration. We report here the use of non-thermal plasma to create a specific atmosphere for epidermal regeneration. We have assessed local and systemic changes during epidermal regeneration under different therapeutic conditions, using a helium atmospheric pressure plasma jet.

The thermodynamical approach is proposed for the optimization of sterilization processes. A comparative study of radio frequency (RF) and microwave (MW) plasmas has been performed, followed by a bactericidal effect investigation for different surfaces contaminated with pathogenic microorganisms. Plasma parameters have been studied by optical spectroscopic methods and microwave dielectric properties’ measurements. Perspective directions for the sterilization process improvement are defined.

An X-ray microbeam fluorescence method was qualified and implemented as a non-invasive solution for the investigation of fusion technology relevant metallic coatings. The method was applied for the non-destructive analysis of the uniformity and thickness of the W coated CFC and fine graphite materials.

We investigate the influence of the magnetic Kubo number, the drift Kubo number and stochastic anisotropy on the diffusion of ions in turbulent, stochastic magnetic fields, applying the decorrelation trajectory method (DCT) and using test-particle simulations. It turns out that the stochastic drifts provide a decorrelation mechanism for the particles from the magnetic lines, and trapping effects are more pronounced, the stronger the magnetic perturbation and the larger the anisotropy in it is. The diffusion coefficients yielded by test particle simulations are in qualitative agreement with those obtained from the DCT method.

In this paper, a study on the multifractal characteristics of intermittency dynamics in a discharge plasma is presented. In order to characterize the singularity spectra, we propose two relevant parameters and investigate the influence of the applied voltage on their magnitude. With increasing of the disorder in the experimental discharge current time series, an evolution of the fluctuations towards Brownian type motion is clearly observed.

The temporal distribution of the concentration of argon metastable atoms in the afterglow of a high voltage pulsed hollow cathode discharge plasma is determined by numerical modeling using the drift diffusion approximation method. The main metastable – metastable collision process consider in this simulations is Ar^M + Ar^M = Ar⁺ + Ar + e with the reaction rate k = 6.4 10^-16 m³/s. The concentration of argon metastables in the 2 – 36 μs temporal afterglow is in the range of 1.87 – 0.33 x 10¹⁹ l/m³. The numerical results are in good agreement with the experimental one obtained by absorption spectroscopy in the afterglow of neon voltage pulsed hollow cathode discharges.

An atmospheric-pressure very cold helium plasma jet generated at 48 kHz in a single-electrode configuration is characterized based on visual observation, gas temperature monitoring and electrical and optical measurements. The plasma is non-aggressive with thermo-sensitive materials, the neutral gas temperature being slightly higher than the ambient one.

In first, we present the performances of the lower power Hall effect thruster SPT-20M7 manufactured by KhAI (Ukraine). In second, we show that the ion energy distribution function in the plasma plume, and recorded by two Retarded Potential Analyser (KhAI and GREMI), exhibits two populations. In third, we indicate the chemical and microstructural changes of the insulated ceramics of the thruster.

This paper documents the design of an RF plasma demonstration unit. The paper shows that there are significant challenges associated with the generation of high frequency plasma under atmospheric pressure, but it yields some interesting results and a simple and elegant design. The generator makes use of a standard power MOSFET in a modern switching amplifier design to produce the required RF power and drive the resonator to produce the high frequency discharge.

The ignition sparks generated by the classical spark plug do not always assure a fast and complete combustion of the mixture hydrocarbon-air. For this reason we propose a new type of double spark plug using two simultaneous discharges generated by a pulsed high voltage power supply. This work presents the spectroscopic analysis of the plasma generated by the classical spark plug in comparison with three electrode spark plug, supplied with trains of pulses containing one or two pulses with variable width. The experiments have been done in air at normal pressure. Because the spectra obtained are clear, stable and repeatable, it was possible to determine the temperatures in the plasma column using a spectroscopic diagnostic method based on the OH UV molecular band spectra.

The GDOES and GDMS analytical systems working in Pulsed RF regime have some distinct advantages compared to non-pulsed glow discharge analytical systems. In this paper we report a rise in MS ionic signals, and in emission atomic lines of analysts in the beginning of the afterglow of RF pulsed GD sources. Making experimental studies with Langmuir probe we demonstrate that the ionization and excitation processes in the early afterglow of the RF pulsed GD involve the metastable atoms of the working gas.

This work reports on the mass spectrometry diagnostic of Ar/thiophene RF plasma generated in parallel–plate discharge configuration at low power levels. The analysis of mass spectra of neutral species shows that thiophene depletion is reaching more than 50% for power level above 5W. At the same time, generation of acetylene, hydrogen and carbon disulfide molecules in plasma and formation of high mass oligomers up to C₁₀H₈S⁺₂ was evidenced.

This paper reports on the investigation of two types of atmospheric pressure plasmas produced by a Dielectric Barrier Discharge (DBD) aiming to increase the efficiency of plasma surface treatment. For this purpose the experiments were performed in a pulsed dielectric barrier discharge, for a plane-parallel geometry, in helium and argon, at atmospheric pressure. The electrical characterisation, emission spectroscopy and diode laser atomic absorption spectrometry techniques were used for diagnosis of the dielectric barrier discharges. The surface modifications of polymer samples (PET) were pointed out by two complementary methods: contact angle and Atomic Force Microscopy (AFM) techniques.

In the present report we compare two types of atmospheric pressure radiofrequency cold plasma sources based on different discharge systems in terms of their spectral properties and the induced modification of the surface properties of various polymeric materials (PET and PE).

The effect of 5.28 MHz plasma and radio-wave treatments on seed sowing quality has been investigated. It has been shown that pre-sowing plasma and electromagnetic treatments during 10–15 min lead to enhancement of laboratory and field germination of seeds, survival and crop capacity.

Silicon is the most common material used in fabrication of commercial atomic force microscopy (AFM) probes. However, the surfaces of the AFM probes surface are rarely clean due to adsorption of airborne and package-released hydrophobic organic contaminants. Cleaning of silicon AFM probes removes the contaminants and renders very hydrophilic probe surfaces. This work presents a simple method of cleaning silicon AFM probes. The method consists in immersing the AFM probes in the negative glow plasma of a glow discharge in air at low pressure. To avoid destruction of the AFM probes, they are kept floating. Cleaning for ten minutes in air plasma at pressure of 6 Torr and cathode current density of 50 μ
A$\cdot$cm^-2 provides a very hydrophilic character to the AFM probe surfaces. The cleaning effectiveness is evaluated by water contact angle measurements of the AFM probe surfaces, which showed a drastic decrease from about 90$^{\circ}$ to less than 5$^{\circ}$. Cleaning of the silicon surfaces of AFM probes and flat samples resulted in significant increase of adhesive and friction forces measured in air on hydrophilic surface of a glass sample.

We report on the micropatterning of teflon foils by a cold atmospheric pressure plasma source, and on the effects of plasma treatment on epithelial cells attachment to surface. The plasma treatment causes wettability improvement and surface roughening. The cell attachment and biocompatibility of foils are both increased by the treatment.

The oxidation of toluene in contaminated air streams was investigated using non-thermal plasma, both in the absence and in the presence of several Ag/Al₂O₃ catalysts, placed downstream of the plasma reactor. The catalysts did not significantly influence toluene conversion, but improved the process selectivity towards total oxidation.

It is widely accepted that the sawtooth oscillations of the plasma parameters (temperature or density) in the central region of a tokamak are closely related to the configuration of the magnetic field. On the basis of some theoretical analysis on the onset of the (1,1) internal MHD mode into the nonlinear regime, we justify the use of the magnetic stochasticity hypothesis in order to explain the sawtooth crash and discuss the complete or incomplete nature of the reconnection. Two magnetic configurations, with monotonous safety factor, respectively with reversed magnetic shear, are studied using the Hamiltonian description of the magnetic field lines and of the mapping technique. A perturbation that contains not only the (1,1) mode, but also higher harmonics is considered and the role of these additional perturbations during the sawtooth crash is observed. The influence of the minimum value of the safety factor, the flatness coefficient and the amplitude of the perturbations on the reconnection process is systematically studied. It is shown that the mathematical models are able to generate poloidal cross sections of the magnetic field lines similar with the experimental ones and a scenario for the reconstruction of the magnetic field during the sawtooth instability is proposed.

There is a fundamental nonlinearity that governs the coherent and cuasi-organised flows in magnetized plasma, high power laser-produced plasmas and planetary atmosphere. It consists of the convection of a vector field by its own velocity field. Unfolding the complexity of this self-interaction is only possible in few, non-generic cases. However a new conceptual approach is possible if we provide freedom to the system, extending the description to a field theoretical framework. We write the Lagrangian densities for ideal fluids and for confined plasma and examine various applications.