High-frequency harmonic generation in a toroidal magnetized laboratory plasma and detection of plasma turbulence

We show for the first time experimentally that plasma turbulence can be detected easily when an electromagnetic extraordinary wave launched from the inner side of a toroidal magnetized plasma reaches a turbulent resonance layer. The second-harmonic wave generated inside the resonance layer is detected from outside the magnetized plasma and its power spectrum is analyzed. This new technique could be developed for distant probing of plasma turbulence.