Temporal evolution of parametrically excited instabilities in a magnetized plasma

The evolution of parametric decay instabilities in a magnetized plasma is studied with an argon discharge. The plasma column is sustained either as an arc discharge or by microwave power. The two decay waves involved are a harmonic of electron cyclotron wave and a cross-field ion acoustic wave, excited parametrically by a microwave pump field linearly polarized in the direction perpendicular to the static magnetic field. The experimental observations of the evolution of the instabilities are analyzed by a phenomenological model that incorporates the linear and non-linear damping effects. (author)