抄録
Standing wave patterns are excited externally in a rf discharge (14-32 Mc/sec) by applying continuous sinusoidal currents (1-100 kc/sec) to a small coil surrounding the discharge tube in a weak axial magnetic field (B0_??_100 G). It is experimentally confirmed that there is no reflection of the waves from the boundary along the axial direction. The wavelengths are found to be independent of the exciting frequency, but inversely proportional to the frequency of the rf discharge. They are proportional to the plasma radius and the magnetic field and do not depend on the plasma density and the ion mass.
The experimental results of the wavelength are well agreement with theoretical values for the space charge waves (Trivelpiece mode) propagating along the plasma column in a weak man.etic field. The excitation of the space charge waves, the frequency of which is equal to that of the rf field for the discharge, is well understood taking into account tha t the rf field perturbs the local space charge produced by the exciting signals. The waves are modulated in amplitude at the exciting frequencies. The standing wave patterns observed at the exciting frequencies are attributed to the synchronization of the waves with the rf field for the discharge.
