Thermal Pinching in Electron-Hole Plasma

A different kind of current pinching than the familiar Bennett pinch effect has been observed in the electron-hole plasma formed in InSb. The new type of pinching is controlled by temperature rather than pressure. It is initiated by the Bennett pinch effect but dominates conduction immediately after the onset of pinching. The necessary critical condition for the onset of this thermal pinch is that the power into the pinch channel less the heat conduction loss be greater than zero. The radii of eight pinch channels have been measured and found to be an order of magnitude smaller than previously thought (∼2×${10}^{-3\mathrm{}}$ cm). The density within the pinches exceeds ${10}^{18}$ ${\mathrm{cm}}^{-3\mathrm{}}$ and the plasma becomes hot enough to cause melting of the lattice within the channel (M.P.=808°K).