© 1968 by Institute of Mathematics and its Applications
The Doppler Effect in a Warm Uniaxial Plasma
Space Sciences Division, Ames Research Center, National Aeronautics and Space Administration Moffett Field, California 94035, U.S.A.
In this paper we consider the character of the radiation emitted by a radiator moving with uniform velocity through a warm, uniaxial plasma. It is shown that the dispersive and anisotropic nature of the plasma plays an important role in determining both the Doppler shift in frequency and the power spectrum of the radiation. The power spectrum and the Doppler relation between the frequency and the direction of the emitted radiation are calculated when (a) the motion is parallel to the magnetic field, and (b) the motion is perpendicular to the magnetic field. It is shown that the Doppler shift and the power spectrum are substantially different in these two cases. The formulae for the {caron}erenkov radiation emitted by a moving charged particle may be obtained from those for Doppler radiation. In the last section we show that a particle moving parallel to the axis of symmetry excites a power spectrum which is linear with frequency, whereas a particle moving perpendicular to that axis excites a power spectrum that is sharply peaked near the plasma frequency.