ANALYSIS OF THE SELF-OSCILLATIONS INSTABILITY DUE TO THE PLASMA COUPLING WITH AN EMISSIVE HOT CATHODE SHEATH

Experimental results are reported showing that plasma self-oscillation s appear when the ion flux arriving at the hot emissive cathode double sheath boundary from a continuous plasma discharge is not high enough to sustain the discharge. Using the stability criterion of a double s heath and the particle balance equations, different conditions for the plasma stability are stated, in good qualitative agreement with exper imental results. A nonlinear analysis giving the noninteger correlatio n dimension in a chaotic self-oscillations regime is also reported, sh owing that a complete understanding of this instability may be reached by a finite set of nonlinear equations. (C) 1996 American Institute o f Physics.