Dynamic characteristics of a hollow copper electrode plasma torch through measurement and analysis of acoustic, optical, and voltage fluctuations

The basic nature of arc root fluctuation in a plasma torch is an extremely important factor from the point of view of improving and optimizing performance of a plasma torch in present-day technology. In spite of a number of ingenious attempts, this particular phenomenon is still not fully explored. In this paper, voltage, acoustic, and optical signals generated from a hollow cathode plasma torch are analyzed using various tools of dynamical analysis such as real-time behavior, phase portraits, power spectra, Lyapunov exponent, dimension, etc. Origin of each of the signal in relation to arc-root fluctuation and mutual correspondence among themselves are described in detail. For the first time, all the signals are found to exhibit clear evidence of chaotic behavior in all respect. A dimensional analysis reveals all the three signals to be originated from the same chaotic phenomenon, i.e., fluctuation of are root.