Zur Theorie elektrostatischer Schwingungen in einem Vlasov-Plasma bei äußerem elektrischen Feld

Longitudinal plasma oscillations under the action of an external homogeneous time dependent electric field are examined with regard to the stability of the plasma. The basic model is an infinitely extended collisionless quasineutral two-component plasma. Starting from the linearized Vlasov equation dispersion relations are derived and discussed. It is shown that for an isothermal two-component plasma instabilities are possible, and limites for the area of instability are given. Further a second method of solution starting from an integral equation for the internal electric field is developed. The equivalence of both methods is shown by means of special cases.     

Zwei Verfahren zur Lösung der Abelschen Integralgleichung und zur Berechnung der radialen Volumenstrahldichte

Two methods for the calculation of the emission coefficient distribution from the side-on radiance distribution in an optically thin plasma were elaborated. Firstly, a method for recursive solution of the Abel integral equation was derived. The formulas given by Frie were simplified. In a second method a polynomial was fitted to the data points and then the integral equation was solved analytically. Fluctuations of the solution increase with rising number of pivot points or with rising degree of polynomial and not only with rising scattering of the data points. The first method provides good results for a relatively small number of pivot points. In many cases the second method provides useful results with an even polynomial of the sixth or eighth degree and the numerical effort is slight.     

Einsteins Feldtheorie mit Fernparallelismus und Diracs Elektrodynamik. III (Statische kugelsymmetrische Lösung der genäherten Feldgleichungen)

Einstein's Field Theory with Teleparallelism and Dirac's Elektrodynamics. III (Static, Spherically Symmetric Solution of the Approximated Field Equations) The static, spherially symmetric solution of the equation of gravitation, considered by Treder [1] and Kreisel [2] and connecting the electromagnetic potential by the Dirac-gauge with the time-like tetrad, is given for the case of small contributions of the space-like tetrads, which corresponds to Einstein-Dirac's electrodynamics. The threedimensional spaces of the solution are two-bladed. The two blades are connected by a wormhole. The solution has a zero of the determinant the metric in the second blade at r = ∞. Therefore the manifold is geodesically incomplete.     

Eine kosmologische Lösung der TREDERschen Gravitationstheorie

A solution of the field equations is given for the case of an universe filled with incoherent matter (p = 0). The observable universe behaves kinematically in a good approximation like the MILNE -model but with flat subspaces t = const.     

Untersuchung der Eigenschaften der Strahlung eines Lasers ohne äußere Rückkopplung

The following article describes the realization of a laser without any external resonance structure and the behaviour of the emitted radiation. The experimental setup consits of a discharge tube closed with Brewster windows and the excitation electronics. The excitation process which brings the atoms to the upper laser level (2 p₆ Neon) will not establish any coherence between the atoms. Space coherence of the radiation has its origin in the correlated behaviour of the radiating atoms. Theoretical and experimental values of the fringe visibility are in close agreement for a path difference till to 440 cm, if temporal coherence is measured in an MICHELSON experiment. Interference fringes result if the radiation emerging from both sides of the tube is superimposed. The contrast decreases rapidly with the number of radiation pulses producing the interference pattern.     

Zur Reversibilität der Vlasov-Gleichung

The difference between Landaus decaying solutions of the linearized Vlasov equation and the damped solutions of a loaded electrical circuit is shown. An integral equation for the field acting in the plasma is investigated and the Laplace transforms of its solutions are considered. Some simple initial value problems for the Cauchy distribution for a perturbation by external fields too, are solved. It is demonstrated that the time arrow in the behaviour of measurable quantities of the Vlasov plasma stems from the accentuation of a non-probable initial state.     

Zur Statistik neutraler Fermionen mit anomalem magnetischen Moment im äußeren Magnetfeld

In this paper we calculate the equation of state of a relativistic uncharged Fermi particle gas in a magnetic field, using the exact solutions of the Dirac-Pauli equation for an uncharged Fermi particle with an anomalous magnetic moment. We find that the stressenergy tensor is anisotropic. The anisotropy is introduced by the anisotropy of energy states.     

Zur Diagnostik der Ionenkomponente im Plasma der äußeren positiven Säule einer stromstarken,unmagnetisierten Argon-Hohlkatodenbogenentladung

This paper reviews two measuring methods of the ions and their results in low pressure plasmas, if spectroscopical methods are not applicable to this situation. The behaviour of ions in the positive column of a high current argon hollow cathode arc was studied in dependence of various plasma parameters with the help of a gridded probe and a quadrupole mass spectrometer. The obtained results were analysed with simple theoretical models and measured electron distribution functions.     

Äquivalente Operatoren der Wechselwirkung zwischen Atomen und elektromagnetischem Feld

As well-known the dynamical interaction theory of molecules or atoms with the electromagnetic field may be based alternatively on one of two HAMILTON ians, ^IH or ^IIH. where the vector potential appears in the interaction term of ^IH while this of ^IIH is expressed in terms of the electric and the magnetic field strength coupled to atomic multipoles. Using a calculus of transversal functional derivation with respect to a vector function we show that we can go from ^IH to ^IIH by a comperatively simple canonical transformation which may be interpreted within the classical theory as well as within as the quantized theory. The equivalence of both HAMILTON ians is lost if, as customary in quantum optics, only a few atomic levels are taken into account. We give a plausible argument that in this case the multipole HAMILTON ian ^IIH is more suitable.