Acousto-convective relaxation oscillation in plasma lamp

Abstract

Periodic instability in sulfur plasma bulbs driven at their acoustic resonant frequency leads to behavior similar to a relaxation oscillation. This instability, which develops over the course of more than 500 acoustic periods manifests as both an oscillation in the total luminosity of the lamp and a frequency modulation of the resonator. We present evidence that the cause of this oscillation cycle stems from periodic eruptions of plasma from within a region near the acoustic velocity antinode. We propose that these oscillations and eruptions indicate a coupling between high amplitude acoustic waves and interface waves and consider whether this system might provide a platform with which to study turbulent heat transport.Periodic instability in sulfur plasma bulbs driven at their acoustic resonant frequency leads to behavior similar to a relaxation oscillation. This instability, which develops over the course of more than 500 acoustic periods manifests as both an oscillation in the total luminosity of the lamp and a frequency modulation of the resonator. We present evidence that the cause of this oscillation cycle stems from periodic eruptions of plasma from within a region near the acoustic velocity antinode. We propose that these oscillations and eruptions indicate a coupling between high amplitude acoustic waves and interface waves and consider whether this system might provide a platform with which to study turbulent heat transport.