Experimental study of the nonlinear properties of the surface-kink instability of a semiconductor plasma in a germanium plate

Abstract

Experiments are reported on the characteristics of the surface-kink instability in germanium plates. The amplitude of the current and potential oscillations, the frequency, and the modulus of the wave vector of the wave are analyzed as functions of the electric field E and the magnetic induction B at 78, 300, and 350°K. The amplitudes of the current and potential oscillations, and also the frequencies, increase with increasing E and B, eventually reaching saturation. At E = const, the modulus of the wave vector is independent of B. It is shown that slightly above the threshold electric field or threshold magnetic induction, i.e., at a small value of Δ [Δg = (E − Et)/Et ≪ 1, ΔB = (B − Bt)/Bt ≪ 1], the curves of the oscillation amplitude vs ΔE; B are linear in logarithmic scale. The slope of the lines is about 0.5, implying a “soft” excitation of the surface-kink instability in the plates.