Some Nonlinear Properties of Electron-Hole Plasmas Sustaining the Helical Instability
1964; American Institute of Physics; Volume: 135; Issue: 5A Linguagem: Inglês
10.1103/physrev.135.a1423
ISSN1536-6065
Autores Tópico(s)Quantum and electron transport phenomena
ResumoElectron-hole plasmas in $p$-InSb are driven far beyond the threshold of the helical instability into the non-linear region by applying axial magnetic fields $B$ much greater than the threshold fields ${B}_{\mathrm{th}}$. While the plasma is immersed in a static $B$ three fundamental properties of the plasma, namely the electric-field strength $E$ sustained in the plasma, the self-magnetic field ${B}_{h}$ produced by the rotating plasma, and the frequency of helical oscillations $f$, are measured. As $B$ is increased from zero, $E$ first decreases until $B={B}_{\mathrm{th}}$; then $E$ rises with a slope and magnitude greater than those associated with the decrease. The quantity $\frac{{B}_{h}R}{{I}_{T}}$, where ${I}_{T}=\mathrm{total}\mathrm{current}$ and $R=\mathrm{radius}$, possesses a maximum as a function of $\mathrm{BR}$. At constant ${I}_{T}$, $f$ exhibits a trend to increase with increasing penetration into the nonlinear region until the onset of turbulence; however, $f$ is a nonmonotonic function of $B$. $E$ is also measured while the plasma is immersed in a magnetic field varying with time at a rate $\stackrel{\ifmmode \dot{}\else \.{}\fi{}}{B}$. The most striking result is the splitting of the ${B}_{\mathrm{th}}$ into two branches with increasing $\stackrel{\ifmmode \dot{}\else \.{}\fi{}}{B}$ as observed by the occurrences of two minima in the $E$ versus time curves. Comparisons are made among all these results and those available on the nonlinear properties of electron-ion plasmas, both experimental and theoretical.
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