Speichernde elektrostatische Bildverstärker mit Mikrolinsen-Kathode und Linsenraster-Speicher

This paper deals with the electron-optical investigation of an image storage tube which is a combination of a flat image intensifier diode and a lens-raster storage system. The imaging system consists of a micro-lens structure formed by a grid (focusing grid) which is located in front of the photocathode. For low positive potential of the focusing grid, small diameters of the writing electron beams are obtained, resulting in a gain of resolution by a factor of 2.1 as compared with a flat image intensifier diode without a micro-lens structure. Measurements of transmission current characteristics of the lens-raster storage grid have been carried out for different shapes of the grid-holes, different optical transparency T_L and thickness d as well as for different values δ (ratio of field strength on the side of the luminescent screen to field strength on the side of the collector). Favourable values with respect to image contrast and brightness were found to be T_L = 0,4, d = 1 (related to the radius of the grid holes) and δ = 10:1.     

Mikrowellendiagnostik nichtstationärer Ne-Plasmen mittels unterschiedlich bedämpfter Hohlraumresonatoren

In this paper is given a modified method of the micro waves diagnostic which reduce in essential way the influence of the instabilities of the plasma on the measuring accuracy.     

Die Entwicklung der Elektronenlawine in den Plasmakanal,untersucht mit Bildverstärker und Wischverschluß

The application of high gain image intensifier and image converter streak shutter techniques to investigations of faintly luminous early stages of gaseous discharges discloses in some detail the development of electron avalanches into anode- and cathode-directed streamers as soon as the critical amplification (n≈10⁸) is attained in the gap. The velocities of both of the streamer branches were measured quantitatively as to the dependence on pressure (p), field (E/p) and gas (Nitrogen and various mixtures), typical values being 0.5 ... 1 · 10⁸ cm/sec. We find that streamer propagation is suitably described in a coordinate-system drifting with the electrons (driftvelocityv _? ≈ 1 · 10⁷ cm/sec) and that the way it depends on the discharge parameters suggests that ionization by electron impact (in the eigen-spacecharge distorted field) and photoionization are the determining effects. — The cathode-directed streamers show a considerable intensification and acceleration as soon as they are encountered by cathodic secondary avalanches, which however are obviously not essential for the initiation of the process in itself. — The streak images give also an impression of persisting excitation and ionization processes in the region of the streamer-paths and of the transition into the beginning of the bright spark, correlated with several ionizing fronts observed moving towards anode or cathode with velocities even >10⁸ cm/sec. (The paper includes also details of the gaseous near UV-radiation which was utilized for registration with image intensifier or converter, especially with respect to the decaytime of the excited states.) The results obtained are essentially a verification and to some extend completion of predictions made on the basis of early cloud chamber investigations.     

Anfachung und Dämpfung magneto-akustischer Wellen in MHD-Kanälen und ihr Einfluß auf die mittlere Stromdichte und die mittlere Hall-Feldstärke

Magneto-acoustic waves generated by fluctuations in the Hall parameter, the electric conductivity and the stream velocity are theoretically investigated in a weakly ionized plasma streaming across a strong external magnetic field and bearing a current flowing perpendicular to both magnetic field and stream velocity. The investigations hold for seeded rare gas plasmas at any degree of seed ionization but are resticted to waves propagating in parallel or antiparallel direction to the current density vector and in parallel or antiparallel direction to the stream velocity vector and to wave lengths which are small in comparsion to the interaction length which occurs as a characteristic wave length. The influence of these waves on the mean current density and the mean Hall field intensity is calculated in case of small amplitudes and low degree of seed ionization up to second order terms. Omitting Ohmic heating the dispersion equation can be solved exactly. A phase shift exists between the fluctuations in gas density and gas velocity. The phase velocity and the amplification rate depend on the wave length. Typical results are represented in a diagram. For both types of waves the phase velocity slightly rises with increasing wave length, while the amplification rate decreases. Waves propagating in opposite direction to the current density vector are amplified, if the electron velocity exceeds a critical value. They reduce the mean current density and the mean Hall field intensity. Waves propagating in opposite direction to the stream velocity vector are also amplified except for very high degrees of seed ionization. The threshold current density is greater than that for the waves of the first type approximately by the Hall parameter as factor. At extremely high degree of seed ionization the phase velocity is directed opposite to the direction occuring at weakly ionized seed. Waves of the second type decrease the mean current density, but increase the mean Hall field intensity.     

Hermitizität und Eichinvarianz

Hermiticity and Gauge Invariance In the Theory of Hermitian Relativity (HRT) the postulates of hermiticity and gauge invariance are formulated in different ways, due to a different understanding of the idea of hermiticity. However all hermitian systems of equations have to satisfy Einstein's weak system of equations being equivalent to Einstein-Schrödinger equations.     

Erhaltungssätze und Topologie

Conservation Laws and Topology It is shown, that for every conserved matter tensor T^ν_μ there exists a frame of reference h^a_μ, orthonormalized in a given gravitational field, such that the components h^a_νT^ν_μ are four conserved currents. The definition of global energy-momentum connected with these currents contains as special causes the definition of inertial frames in Minkowski space as well as the definition of energy in a comoving system in presence of Killing vectors in general relativity. Given on the other hand four closed 3-forms in a space-time with non-trivial topology, one can introduce an orthonormal frame of reference h^a_μ in such a way, that the space-time- components of the 1-forms, dual to the given 3-forms, define a symmetric matter tensor, which generates according to Einstein's equations the gravitional field. This means a partly topological definition of matter, since the non-trivially closed part of the 3-forms is determined by the topology of the manifold.     

Integrabilität,Irreversibilität und Kosmogonie

Integrability, Irreversibility, and Cosmogony Leading the famous discussion with Boltzmann on the foundation of statistical thermodynamics Zermelo was backed by Planck himself. Zermelo's objections to Boltzmann's atomism and Boltzmann's answers are again vital today. After all Boltzmann founded statistical thermodynamics cosmogonically.