Intermittent Behavior of Local Electron Temperature in a Linear ECR Plasma

Abstract

An intermittent behavior of local electron temperature has been observed in a linear laboratory plasma, where a high-temperature region that has circular cross-section is formed along the magnetic field line for a short period of time. The floating potential signals which contain sporadic large-amplitude negative spikes associated with the electron temperature intermittency are analyzed statistically for various gas discharges. All the probability density functions of waiting time for different gas discharges exhibit exponential distributions, indicating that the random nature of this phenomenon, or the underlying Poisson process, is a universal property. On the other hand,mean duration of the intermittent events depends on the atomic mass of discharge gas species, showing that the dynamics of heavier particles may play an important role in this intermittency.