Kakuyūgō kenkyū

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In the cold-collisionless plasma theory, it is shown the whistler mode propagates through an overdense magneto-plasma (i.e. a plasma whose plasma frequency is greater than the frequency of the wave) at a frequency that is below the electron cyclotron frequency of the plasma.
In the actual laboratory plasmas, the effects of the collisions may play an-important-role in the propagation of the waves. Those 4fects are examined in the case of a warm plasma, such as the after grow plasma. As the temperature is very low in this case, it is resonable to consider Coulomb interaction may play a dominant part rather than electron-neutral collisions.
In this paper, we obtained the dispersion equation and the apatial-damping constants of the whistler mode by applying Comisar's method (treating the collisional terms which appear in the Boltzmann-Fokker-Planck equation for longitudinal plasma oscillation) to the corresponding problem for the transverse waves in the presence of uniform magnetic field. The results of calculations are shown to be in good agreement with experiment.

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The behaviors of a charged particle which moves from a point of week field toward a strong field region in cusped field are investigated.
The equation of motion of a charged particle in cusped field is non-linear and second order with respect to r or a in cylindrical coordinates.
By certain transformation which eliminate non-linear terms, it can be reduced to the same kind of equation as that represents the motion of a charged particle in a homogeneous magnetic field which varies in time.
If the change in the magnetic field over the distance which a charged particle displaces during one gyration is small, the approximate solution of it can be obtained by means of WKB method.
Such a solution reveals the adiabatic orbit of a charged particle, and also its adiabatic invariant can be obtained.
The region in which a charged particle behaves as an adiabatic one is roughly estimated.

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