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 front the hot plate. Synchronous quenching is also observed: A relation a 2 +α b 2 =const. is obtained between the amplitudes a and b of the spontaneous and excited flute modes (whose frequencies are f 0 and f ex ), respectively. The factor α depends on the frequency discrepancy and the position of observation: α=0.17 and 0.3 for ( f 0 - f ex )/ f 0 =0.28 and 0.13, respectively.