Comparison of dynamic behavior of LaB6 and SiO2 dusty plasmas in response to photo-discharging

Experiments with dust particles composed of either lanthanum hexaboride (LaB6) or silica (SiO2) have demonstrated that both respond when exposed to high-intensity near-ultraviolet (NUV) light in a manner consistent with photo-discharging. While some particles exhibit reproducible periodic motion in response to the NUV exposure, others exhibit more chaotic behavior. Computational investigation into the response of the dust suggests that particle geometry may play a role in determining whether particles trend towards a periodic or chaotic response. To test this hypothesis, different samples of LaB6 and SiO2 dust are suspended in low temperature plasmas and exposed to a pulsing NUV source. Video data is used to analyze the motion in phase space of several isolated particles and determine whether SiO2 microspheres exhibit a more consistently periodic response than irregularly shaped LaB6 particles.