Nonlinear behavior of Drift wave oscillations in a single-ended Q-device

Harmonic Drift wave oscillations accompanied by sidebands have been observed in a single-ended Q-device with collisionless Lithium plasma. The power spectrum of the harmonics is found to fall off with frequency as fsup(-4.8+-0.6) in agreement with the theoretical prediction of plasma turbulence by F.F. Chen. The generation of sidebands due to trapped particles by the wave is inconsistent with the results. It is probably due to the modulation of the drift wave by the low frequency oscillation which is observed simultaneously. A transition from a discrete spectrum to turbulence occurs as the magnetic fields is increased and the formation of turbulence appears to be related to sideband interactions. (auth.)