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  • 1
    Electronic Resource
    Electronic Resource
    Die Elektronenbewegung im Neutralgas bei hohen elektrischen Feldern (1962)
    Springer
    The European physical journal 169 (1962), S. 432-455 
    Details
    ISSN: 1434-601X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract In strong electric fields the acceleration of the electrons by the field exceeds the deceleration by collisions with neutral molecules. Thus run-away or beam electrons are produced. This paper investigates the motion of the beam electrons in a neutral gas considering ionization processes by electron-molecule-impacts. We start with a time independent current of primary electrons (case a) and a space independant density of primary electrons (case b). The further development of the velocity distribution is calculated. For a molecular hydrogen gas the amplification of the initial electrons, the average ionization, and the velocity distribution of the electrons as a function of space or time respectively is given. The average ionization has an asymptotic solution, which becomes valid, when one primary electron has produced by ionization an avalanche of approximately 100 electrons. The Townsend coefficient α for high values of the field strength is independant of space only in the region of this asymptotic solution.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01378171
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  • 2
    Electronic Resource
    Electronic Resource
    Normaler und minimaler Kathodenfall der Glimmentladung (1964)
    Springer
    The European physical journal 178 (1964), S. 319-334 
    Details
    ISSN: 1434-601X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract A two-dimensional theory of the glow discharge is developed, describing the radial distribution of the current density at the cathode. The main deviation from the one-dimensional description is given by an additional contribution to the balance of the charge carriers, due to radial diffusion. For the radial distribution of the current density a differential equation of the diffusion type is derived. By numerical integration a set of current distributions is calculated. In a voltage-current diagram the difference between the normal and the minimal cathode fall can be demonstrated. The minimal cathode fall corresponds to a constant, infinitely extended current distribution, whereas the normal cathode fall corresponds to a current distribution, which tends to zero at the edge. A slight dependence of the normal cathode fall on the radius of the discharge can be shown.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01377855
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  • 3
    Electronic Resource
    Electronic Resource
    Ionenbewegung unter dem Einfluß von Umladungsstößen (1967)
    Springer
    The European physical journal 200 (1967), S. 343-365 
    Details
    ISSN: 1434-601X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract The motion of ions under the influence of an electric field and a density gradient is investigated by taking into account only charge-transfer collisions between the ions and a neutral gas background. The two model cases of constant mean free path and constant mean free time are considered. For weak electric fields the Boltzmann equation can be solved using a special expansion of the velocity distribution. The expansion in Sonine polynomials as given by Chapman and Cowling does not converge. For medium and high electric fields the velocity distribution is calculated by collecting the contributions of the different paths of the ions. The inhomogeneous drift in high electric fields is investigated for a small perturbation by gradients of the electric field, the ion density and of the mean free path.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01326177
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  • 4
    Electronic Resource
    Electronic Resource
    Die wandbestimmte Vernichtung angeregter Teilchen in Plasmen (1975)
    Springer
    The European physical journal 20 (1975), S. 201-206 
    Details
    ISSN: 1434-6036
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract Time resolved optical absorption measurements on low pressure afterglow plasmas show that metastable atoms are reflected by the wall ten to hundred times. This high rate of reflection changes drastically the pressure dependence of the decay frequencies in the diffusion range. No microscopic diffusion theory exists taking in account this effect. Starting from the Boltzmann equation we developed such a diffusion theory. The microscopic boundary condition was described by a model of the transport to the wall and of the plasma-wall interaction. From the solution of the Boltzmann equation we derived a macroscopic boundary condition which gives the diffusion current as a fraction of the thermal current. Up to now this fraction was found by semiempirical considerations only.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01315691
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  • 5
    Electronic Resource
    Electronic Resource
    Die kathodischen Entladungsgebiete der nichtstationären Glimmentladung (1961)
    Springer
    The European physical journal 164 (1961), S. 40-54 
    Details
    ISSN: 1434-601X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract The basic equations of the cathode fall region are linearized for small perturbations from a stationary state. The calculation is based on a one dimensional model. The linearized system of equations is solved by series expansion in space and time. As a result, a linear differential equation for the discharge current and the cathode fall, the differential characteristic is obtained. The inclusion of the first main terms allows a transformation of this differential characteristic into a differential equation of an electric circuit, consisting of an ohmic resistanceR, a self inductanceL and a capacitanceC. The termsR, L, C are given as functions of discharge parameters, which may be determined experimentally or theoretically for the stationary glow discharge. Two different cases are considered. In the first case the influence of the ionic transient time through the cathode fall region is investigated. The second case takes into account the diffusion of metastable atoms from the glow to the cathode. The results may be applied in stability considerations, in the investigation of the production of oscillations within the cathode fall region and in the description of a glow discharge produced by an external direct voltage with a small superimposed alternating voltage.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01377648
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  • 6
    Electronic Resource
    Electronic Resource
    Untersuchung von run-away-Elektronen im Neutralgas (1964)
    Springer
    The European physical journal 179 (1964), S. 52-61 
    Details
    ISSN: 1434-601X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract The theory of run-away electrons is applied to a special device, where electrons of a given initial velocity move in a neutral gas through a homogeneous electric field. The average velocity of the electrons as a function of the space coordinate for different initial velocities and relative electric fieldsE/p is calculated. In an experimental investigation of this case the velocity distribution of the electrons after their passage of the field space for different initial velocities and relative fieldsE/p is analyzed. Within the range of experimental errors the measured average velocities agree with the calculated ones. On the basis of these experimental velocity distributions the runaway effect at large initial velocities but medium electric fields can be demonstrated.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01379213
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  • 7
    Electronic Resource
    Electronic Resource
    Optimierung von nichtthermischen Plasmen auf plasmachemische AnwendungenErweiterte Fassung eines Vortrages bei dem Industriekolloquium „Plasmachemie“ im Battelle-Institut e. V., Frankfurt/M. am 6. Mai 1971. (1973)
    Weinheim : Wiley-Blackwell
    Chemie Ingenieur Technik - CIT 45 (1973), S. 122-130 
    Details
    ISSN: 0009-286X
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: In einem nichtthermischen Plasma werden aktive Spezies erzeugt, die zu chemischen Reaktionen führen. Im Hinblick hierauf läßt sich eine Optimierung entwickeln, die noch keine speziellen Eigenschaften des Plasmas enthält. Als erster Optimierungsschritt wird gefordert, daß der Anteil der elektrischen Leistung für die Aufheizung des Gases vernachlässigbar ist gegenüber dem Anteil für die Erzeugung der aktiven Spezies. Dies ist oberhalb eines kritischen Wertes des Energieverlustfaktors für die Elektronen gegeben. Als nächster Optimierungsschritt wird eine möglichst hohe Produktionsrate der angeregten Atome verlangt. Für Felder oberhalb des kritischen Wertes ist dies gleichbedeutend mit der Forderung nach einer hohen elektrischen Leistungsdichte. In den meisten nichtthermischen Plasmen läßt sich der erste Optimierungsschritt realisieren. Weitere Optimierungsschritte müssen für die einzelnen Entladungstypen getrennt diskutiert werden. Besondere Bedeutung kommt dabei der Gasströmung durch das Plasma zu.
    Additional Material: 9 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cite.330450306
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