Numerical mode and boundary analysis of bifurcation phenomena in plasmas with stationary striations

A non-linear phenomenon occurring in radio-frequency-excited inert gas plasmas with zero d.c. magnetic field results in the formation in the plasmas of stationary striations induced by the onset of an instability. This instability has theoretically been found to depend on various bifurcation parameters which can be experimentally controlled. Some experimental results have been obtained and compared with theory. Striations have been observed in neon and argon under a wide range of operating conditions. Transitions between modes caused by changes in the length, power or pressure exhibit hysteresis. The hysteresis in some parameter regions appears to be due, at least in part, to the flexibility of the boundary. Criteria are proposed for the automatic localization of the plasma boundaries. A computer program has been written for the application of the same to digitized experimental runs and for the analysis of corresponding plasma modes. The results of the analysis of several cases of particular interest are presented, and comparisons are made with theory