Zur mikrophysikalischen Beschreibung des schwachionisierten Säulenplasmas von Glimmentladungen in Stickstoff‐Neon‐Gemischen III. Bilanzierung des Säulenplasmas und Berechnung seiner inneren Parameter

Abstract

InhdtsiibersichtAusgehend von der Analyse der elektronenkinetischen Eigenschaftendes Stickstoff-Neon-Gemisches [l, 31 werden fiir stromschwache Silulenplusmen solcher Gemische die Bilanzcn der das globale Siiulenverhalten bestimmenden Ionenarten und angeregten Spezies formuliert. BIittels einer simultanen Losung dieser Bilanzen zusammen mit der Boltzmann-Gleichung der Elektronen des Gemisches, der Strombilanzgleichung und der Quusineutralitiitsbeziehung wird die Entladungsstrom-und Druckabhiingigkeit des axialen Siiulengradienten, des Ionisierungsgrades und der Konzentration der angeregten Neon-Atome und der Ionenarten fiir beliebige Zusammensetzung des N, -Ne-Gemisches berechnet. Bei der Ermittlung der Strom-und Druckabhlngigkeit der Sauleneigenschaften werden die Bereiche 0,5 mA-13,5 mA und 0,37 Torr-3.7 Torr erfaBt. Ein fur den axialen Siiulengradienten vorgenommener Vergleich theoretisch berechneter Ergebnisse mit dem Experiment fiihrt zu einer guten ubereinstimmung im Gebiet storungsfreier Slulenplasmen.GroRe Bedeutung in der Ladungstrlgererzeugung kommt in dem untersuchten Gemisch der Ionisation der Stick$offmolekiile durch StoBe mit den metastabilen Neonatomen (Penning-Ioiiisation) zu. Ausgehend von experimentell bestimmten Siiulengradienten wurde die StoBrate z p fur die Penning-Ionisation ermittelt. Es ergab sich ein gegeniiber friiheren Untersuchungen [9] etwas kleinerer Wert von z p = 3 . lo-" cm3 s-1. SummaryFor the plasma of the low current positive column in the N,-Ne-mixture the equations for the concentration of different kinds of ions and excited particles are set up. The axial electric field strength, the degree of ionization and the concentration of excited Ne-atoms and of the different kinds of ions are calculated by simultaneous solution of these balances together with the electron Boltzmann equation for this mixture and the balances for the electric current and quasineutrality of the column plasma. All these macroscopic properties of the discharge column are investigated for electric currents of 0.5 mA to 13,5 mA, for total pressures of 0,37 torr to 3,7 torr and for any mixture ratio. A comparision between measured and calculated electric field strengths shows a good agreement. The ionization of the N,-molecules by collisions with the metastable Ne-atoms (Penningionization) is of great significance for the generation of new charge carriers in such a mixture. In these investigations the collision rate zp of the Penning-ionization was obtained to 3 . 1O-l1 om3 s-l by the aid of a comparision between measured and calculated electric axialgradients of the column. S. Pvau und It. WINKLER

New procedure to estimate plasma parameters through the q-Weibull distribution by using a Langmuir probe in a cold plasma

“…In the case of Nitrogen plasma, the q-Weibull function may fail to represent dips and peaks in the EEPF at higher electron energies (above 5 eV), as it was reported in Refs. [66,67,68], however these effects are of some order of magnitude below the maximum value of the EEPF, and therefore could contribute only a small amount compared with the low-energy electron peak which is the part of the curve which better fits the q-Weibull function. This may be a subject of future investigations.…”

Experimental investigation of excitation of argon metastables by an electron swarm in argon nitrogen gas mixtures

“…It has been noticed in the high precision swarm experiments [-40-42] that the addition of molecular impurities in the ppm range (especially nitrogen in argon) could lead to erroneous results for drift velocities and diffusion coefficients. Further investigation has been carried out for the case of Ne-N 2 mixtures [43][44][45], and it is very important even for the case of our Ar-N 2 mixtures. It is evident from these papers that for low values of impurity concentrations there is only a slight effect on both mean electron energy and corresponding transport parameters.…”

Kinetic Description of the Stationary Band‐Like Weakly Turbulent Beam Discharge Plasma in Hydrogen. I. Basic Equations — Numerical Approach — Ionization and Dissociation Budget

“…If we use z as the coordinate in band direction parallel to the magnetic field, the awbipolar current densities jk+ (k = 1 , 2, 3) for the different ions are given hJ- [5] R. WIXKLER, P. ~LICHEL, S. PFAU, V. V. STARYKH, J. WILHELZI where D e , be and bkdenote the diffusion coefficient, the iiiobility of the electrons and the mobilities of the different ions in the H/H2-mixture, respectively. This results from the condition of ambipolarity of the axial electron and ion currents and from the condition of quasineutrality.…”