Abstract
This paper investigates the behavior of a radial plasma jet array and its interaction with various cylindrical targets. The jet array comprises six individual plasma jets arranged around a circle at even spaces, directed towards a common central axis, where the cylindrical objects are to be treated. The interaction of the six jets without the target is studied. The effect of pulse rise time on the electrical and optical properties of the plasma jets is investigated. The spatial–temporal evolution of the plasma jet array and its interaction with (1) dielectric target, (2) floating metallic target and (3) grounded metallic target, are studied respectively. It is calculated that the velocity of the ionization front in these three cases, although differs amongst themselves, is in general greater than that in the no-target case. The luminosity and the profile of the ionization wave front are noticeably different in these three cases: comparing to the no-target case, the intensity of the ionization front reduces with the presence of a dielectric target, while the luminosity of the ionization wave front is enhanced with the presence of a metallic target (either floating or grounded). Optical emissions at the quartz nozzle exit and at the central axis are different with different targets. The different behavior of the jet array with the presence of different targets is attributed to the local electric field distribution, which will be discussed in this paper.