抄録
Both the experimental and the theoretical studies on the controlled excitation of the helical wave are made in weakly ionized mercury, helium and neon discharge cylindrical plasmas with a longitudinal magnetic field below the critical field value. The phase constant of the excited wave has almost linear relation with exciting frequency and becomes larger as the applied uniform magnetic field increases. The attenuation constant has a peak value near the critical frequency and the attenuation of the wave becomes smaller with increasing magnetic field. These relations are analysed theoretically as a kind of an electron drift resistive wave. The comparison of the experimental results with the calculated ones is in good agreement.
