Excitation and nonlinear phenomena of flute instability in a Q-machine plasma

Flute mode oscillations are excited in a single-ended Q-machine plasma by applying three phase voltage to electron emissive grids (coated with BaO) heated by the thermal radiation from the hot plate. Synchronous quenching is also observed: A relation a2 + αb2 = const. is obtained between the amplitudes a and b of the spontaneous and excited flute modes (whose frequencies are f0 and f sub(ex)), respectively. The factor α depends on the frequency discrepancy and the position of observation: α = 0.17 and 0.3 for (f0 - f sub(ex))/f0 = 0.28 and 0.13, respectively. (author)