摘要:

AbstractStarting from former investigations concerning the collision dominated relaxation of the electron component in weakly ionized inert gas plasma we generalize the results obtained. Also in the present paper we use the same adaquate kinetic equation for the electron energy distribution function. On one side the influence of non‐stationary, analytically given initial energy distributions on the relaxation behaviour and on the resulting adjustment time of stationary states was investigated. On the other side the calculation, especially of the adjustment time, was extended to a whole variety of final stationary states ranging from those determined only by energy loss due to elastic collisions to those determined only by exciting collisions. The adjustment time obtained varies by about four orders of magnitude within this wide range of final stationary state

ISSN:0005-8025    

DOI:10.1002/ctpp.19800200402

出版商:WILEY‐VCH Verlag    

年代:1980

数据来源: WILEY

摘要:

AbstractA system of differential equations describing the radial profiles of the number densities and of the radial drift velocities of the ions and of the electrons in positive columns at low pressure containing several species of ions is derived. Excited ions and doubly charged ions, generated in two‐step processes by electron impacts, the inertia of the ions and space charge effects are taken into account. For the excited ions de‐excitation processes by electron collisions and by spontaneous emission are regarded. A set of nonlinear equations to determine the population densities and the initial values of the differential equations and corresponding boundary conditions are put up. Numerical solutions are given for discharges in argon under free‐fall conditions similiar to argon ion lasers. One notices that without stepwise processes via excited ion levels the concentration of double charged ions remains small. In some cases the radial drift of the ions considerably reduces the population of the metastable ion levels. The radial density profiles of the double charged ions and of long‐living excited ions considerably deviate from the squared radial profile of the electron density. In addition, for low degrees of ionization the theory of the free‐fall column given by Tonks and Langmuir is extended to plasmas containing two specie

ISSN:0005-8025    

DOI:10.1002/ctpp.19800200403

出版商:WILEY‐VCH Verlag    

年代:1980

数据来源: WILEY

摘要:

AbstractAuf der Grundlage der Lösung der Boltzmann‐Gleichung für das Elektronengas werden die Teilchenbilanzen verschiedener Ionen (H+, H2+, H3+, H3+, H5+) und der neutralen Komponenten im H/H2‐Säulenplasma unter Berücksichtigung zahlreicher Elementprozesse (Volumen‐ und Wand‐prozesse) diskutiert. Dies liefert ein detailliertes Verständnis der elektrischen Charakteristik des Plasmas in Verbindung mit der chemischen Zusammensetzung des Gases. Im Bereich kleiner Drücke und höherer Ströme treten große Dissoziationsgrade auf. Experimentelle Untersuchungen bestätigen diese theoretischen Ergebnisse. Auf noch bestehende Unterschiede zwischen der gemessenen und berechneten elektrischen Charakteristik

ISSN:0005-8025    

DOI:10.1002/ctpp.19800200404

出版商:WILEY‐VCH Verlag    

年代:1980

数据来源: WILEY

摘要:

AbstractHg‐light absorption at λ = 2537 Ǎ by O3has been used to measure the concentration of O3in the positive column of an oxygen glow discharge under the nonstationary conditions of the Q‐form (tube diameter 3:4 cm). For all gas pressures investigated (p= 7 — 12 torr) the O3density (n3) as a function of the current reaches a remarkable maximum ati≈ 15 mA.n3maxwas found to increase almost linearly with the gas pressure. At i= 80 mA, on the other hand,n3increases according to a quadratic relation.In order to understand the dependence ofn3on the pressure and on the current density (or equivalently on the electron densityne) a kinetic model previously developed has been used involving the following particles.For example, it can be shown that in the region of the maximum ofn3one main production process of ozone is the associative detachment reaction.The calculated maximum of the ozone density is higher than the measured one and appears at higher electro

ISSN:0005-8025    

DOI:10.1002/ctpp.19800200405

出版商:WILEY‐VCH Verlag    

年代:1980

数据来源: WILEY

摘要:

AbstractNonideal plasmas have been generated by mechanical compression with a so‐called ballistic compressor. The Debye numbers reached were 0.4 in argon and 0.2 in xenon. The experimentally determined pressure, specific volume, and temperature are compared with calculations of the compression using different models of the charged particle interaction. This comparison shows that heat losses may take an essential part in the interpretation of the experimental result

ISSN:0005-8025    

DOI:10.1002/ctpp.19800200406

出版商:WILEY‐VCH Verlag    

年代:1980

数据来源: WILEY

ISSN:0005-8025    

DOI:10.1002/ctpp.19800200401

出版商:WILEY‐VCH Verlag    

年代:1980

数据来源: WILEY