摘要:

AbstractThe axial electrical field strength in the positive column of glow discharges at small currents in noble gases passes through a maximum with the increase of an axially directed magnetic field. This maximum is explained of the contrary processes of extension of the radial profiles of the electron energy and the concentration of the metastable atoms on the one hand and the decrease of the ambipolar diffusion losses on the other hand. Using the results of measurements of metastable atom concentrations, the electrical field strength is calculated as a function of magnetical induction with the aid of a set of balance equations. The radial and axial distribution of the electrons is checked by probe measurements. The methods for measuring the concentration of the excited atoms and the electrons are described.

ISSN:0005-8025    

DOI:10.1002/ctpp.19830230402

出版商:WILEY‐VCH Verlag    

年代:1983

数据来源: WILEY

摘要:

AbstractThe time‐averaged probe current is calculated by using a sampling method for sinusoidal and sawtooth‐like oscillations of the space potential. The effect of oscillations on the measured plasma parameters obtained with the aid of the single probe method, double probe method and the method of the second derivative of the probe characteristic is discussed, with the electron saturation current being taken into account. In the ion current the valuesrp/λD, λ/rpandMicharacterizing the working regime are varied. The calculated results are checked by corresponding measurements in a beam generated p

ISSN:0005-8025    

DOI:10.1002/ctpp.19830230403

出版商:WILEY‐VCH Verlag    

年代:1983

数据来源: WILEY

摘要:

AbstractIn this note we present the first account of a study of metastable (unimolecular decay) and collision‐induced dissociation of Ar3+ cluster ions using an experimental setup consisting of a molecular beam‐electron impact ion source and a double focussing (reversed Nier Johnson geometry) mass spectrometer. The existence of the following metastable decay processes (accessible by our sampling time window) could be demonstrated: Ar3+* → Ar2+ and Ar3+* → Ar+. The processes were studied as a function of electron impact energy. The present results are of importance in order to provide some guidance for the development of appropriate theoretical models for the dissociation of clust

ISSN:0005-8025    

DOI:10.1002/ctpp.19830230404

出版商:WILEY‐VCH Verlag    

年代:1983

数据来源: WILEY

摘要:

AbstractIn this paper the comparison of coronal and collisional‐radiative models of the plasma of the positive column of hydrogen glow discharge is made. From the good agreement between theoretical and experimental results it follows that both models are suitable for description of the two spectral lines intensities ratio dependence on electron temperatur

ISSN:0005-8025    

DOI:10.1002/ctpp.19830230405

出版商:WILEY‐VCH Verlag    

年代:1983

数据来源: WILEY

摘要:

AbstractIn this paper it is shown that there are, in dependence on the properties of the system, several systems of nonlinear equations for the description of the nonlinear “hydrodynamical stage” of the beam‐plasma instability. It becomes evident that the well known system of equations for the resonant wave instability in beam‐plasma systems is not applicable for the case of strong dissipation of the wave energy in the plasma and for the case of the excitation of nonresonant waves. As well for the time‐problem as for the space‐problem there are derived three different systems of nonlinear equations. An energetic analysis of the nonlinear stage of the excitation of resonant waves is given. Anomalous growth of the amplitude of resonant waves by interaction with strong modulated electron beams

ISSN:0005-8025    

DOI:10.1002/ctpp.19830230406

出版商:WILEY‐VCH Verlag    

年代:1983

数据来源: WILEY

摘要:

AbstractIt is the purpose of this paper to give a general form for the isotropic and vectorial part of the distribution function for electrons, in a fully ionized and magnetized plasma, interacting with an alternating electric field.By making the assumption, that the ions have an equilibrium distribution, we obtain the needed solutions as series with respect to time and complex exponentials. Also have indicated a new manner in which the solution may be obtained with any precission we want. A general form for density current is obtained. It should be denoted that these results are obtained, without being done any previous assumption on the temporal dependence of the distribution function.

ISSN:0005-8025    

DOI:10.1002/ctpp.19830230407

出版商:WILEY‐VCH Verlag    

年代:1983

数据来源: WILEY

摘要:

AbstractThe interaction of a partially ionized continuum gas with a negatively charged electrode is investigated theoretically. It is supposed thatld≪ 1, whereldis the Debye length,lis the mean‐free‐path. The self‐consistent solution is given for two cases:lI≫landlI∼ l, lIis the effective ionisation length. The matched asymptotic expansions method is used. The Bohm sheath criterion is shown to be satisfied automatically in the consi

ISSN:0005-8025    

DOI:10.1002/ctpp.19830230408

出版商:WILEY‐VCH Verlag    

年代:1983

数据来源: WILEY

摘要:

AbstractThe dynamic stability of a stratified layer of a partially ionized, self‐gravitating plasma is studied to investigate the effects of finite electrical conductivity. The whole system is immersed in a uniform vertical magnetic field. It is first shown that the solution is characterized by a variational principle. An explicit solution has been then obtained for a semi‐infinite composite plasma in which the density has a one‐dimensional gradient along the vertical.Numerical calculations show that the influence of neutral gas friction and self‐gravitation is stabilizing whereas character of finite electric conductivity is destab

ISSN:0005-8025    

DOI:10.1002/ctpp.19830230409

出版商:WILEY‐VCH Verlag    

年代:1983

数据来源: WILEY

摘要:

AbstractA review of mechanisms of the initiation of vacuum breakdown is presented and role of anode surface contaminations in enhancement of prebreakdown currents and initiation of breakdown is emphasized. The experimental investigation of vacuum breakdown and prebreakdown phenomena is described. Experiments presented herein show the desorption of anode contaminations under electron bombardment to be an essential factor of stimulation of electrical breakdowns. Possible influence of desorbed gases on prebreakdown state of electrodes is analysed.

ISSN:0005-8025    

DOI:10.1002/ctpp.19830230410

出版商:WILEY‐VCH Verlag    

年代:1983

数据来源: WILEY

ISSN:0005-8025    

DOI:10.1002/ctpp.19830230401

出版商:WILEY‐VCH Verlag    

年代:1983

数据来源: WILEY