No abstract available

No abstract available

[en] The onset is described on the example of neon of a transition from a non-hydrodynamic state of the electron gas, which exists at low pressures and currents, to a state where a local hydrodynamics is applicable. In the non-hydrodynamic state the ionization waves are influenced by the resonant properties of the electron gas which means that several varieties can be selected on each of the two dispersion curves. With increasing current the two parts of dispersion curve of the fast varieties (r and s) merge and this is interpreted as the disappearance of the spatial resonance of the electron gas due to an enhancement of electron Coulomb collisions. (author)

[en] The damping of moving striations were investigated in direct current glow discharges. The use of tapered discharge tube made it possible to create longitudinal inhomogeneous plasma in which the conditions for the excitation of striations vary along the tube. The characteristics of different damping striations were measured and plotted on the pressure-current plane. The effects of tube geometry on the damping process were studied. (D.Gy.)

No abstract available

[en] The influence of ionization waves irregularity on electron distribution function measurement was investigated. The probe method and sampling technique was applied. The results show that the time irregularity of high amplitude ionization waves may cause an error in the interpretation of the electron distribution function measurement. (author)

[en] The striations observed on the Hα or Hβ emission signal of ablated pellets are not presently well understood. A limitation of the ablation process due to the lesser amount of energy available on resonant magnetic surfaces would be an attractive explanation. In order to evaluate the ability of the latter to produce the observed features, we developed a model which takes into account the maxwellian distribution of electrons, the proportion of trapped particles, the geometrical effects linked to the shear and the finite lifetime of the filaments. In tokamaks, it is found that our model is unable to reproduce the observed striations for smooth q profiles but that the general shape of the Hα (or Hβ) signal can be fitted by introducing small flattenings (e.g. small magnetic islands) around resonant surfaces. In low-shear stellarators, striations (rather shallow) due to rational q values can exist in the absence of magnetic islands but require the presence of a suprathermal electron tail. (author). 17 refs, 2 figs, 1 tab

[en] The development of electron kinetics in glows discharges is reviewed. The historical background is presented, and some topics of recent interest are discussed. It is shown that electron kinetics is one of the essential areas of modern low-temperature plasma physics, and many phenomena that are characteristic of glow discharges, such as the structure of the electrode regions and striations, are essentially kinetic in nature.

[en] Having observed formation of plasma striations in an Electron Cyclotron Resonance Heating (ECRH) device, we have studied the conditions under which the hollow cylindrical plasma columns would develop into striations. We first present the observed conditions of the hollow cylindrical plasma which would develop into plasma striations, the measured characteristics of the transverse oscillations and a simple small signal model for a transverse instability in a weakly-ionized hollow cylindrical plasma. This linearized model, which assumes flowing cold ion fluid (T/sub i/ approximately < 0.1 eV) in warm electron fluid (T/sub e/ approximately 1 eV) and background neutrals, reveals a transverse flute-type electrostatic instability whose characteristics are in qualitative and quantitative agreement with the measured values of the oscillations in our experiment

[en] We propose a new method of finding the mutually unbiased bases for three qubits. The key element is the construction of the table of striation-generating curves in the discrete phase space. We derive a system of equations in the Galois field GF(8) and show that the solutions of these equations are sufficient for the construction of the general sets of complete mutually unbiased bases. A few examples are presented in order to show how our algorithm works in the following cases: striation table with three and two axes, and one and no axis in the discrete phase space. (paper)