抄録
The eigenvalue. thory of Vlasov Plasma Oscillations developed by Case andother autors, is applied to the case where the waves propagate obliquely to the direction of constant magnetic field, externally imposed on a spatially homogeneous plasma. The plasma may have a general equqilibrium distribution with certain few weak conditions. Many elliptically polarized high harmonic waves superpose in a transversal electric wave. This superposition, being impossible to he avoided by the choice of the condition, makes an anharmonic plasma oscillation, because of different phase velocities of partial waves. The spectra of the phase velocity are partly similar to those of velocity of density waves, and are derived from the dispersion equation. The spectra are, however, masked by other terms and disappear, when the direction of propagation becomes perpendicular to the direction of the external magnetic field; so also do the phenomena due to the spectrum like Landau dampings, microirstabilities and so on.
