Experimental evidence of chaotic behavior in atmospheric pressure arc discharge

In free burning as well as in stabilized arc columns, the inherent movement of arc root results in fluctuation in arc voltage. A full knowledge and control over the arc root dynamics can effectively lengthen the life time, drastically improve performance and reliability in arc plasma devices. In this paper, we experimentally investigate the fluctuating voltage signals generated from an atmospheric pressure arc discharge produced in a hollow electrode plasma torch. For the first time, analysis of these signals reveal them to exhibit chaotic behavior. The present analysis is supported with real time behavior, phase portraits, power spectra and Lyapunov exponents. Dependence of system behavior on various control parameters is also investigated. This approach is interesting in the sense that it can lead to better understanding of physics for future researches on arc plasma jets and related devices.