Document Type

Theses, Ph.D


Available under a Creative Commons Attribution Non-Commercial Share Alike 4.0 International Licence



Publication Details

This thesis submitted in fulfilment as part ofthe requirements of a PhD


Non-thermal plasma (NTP) has been a point of interest in many areas over the last few decades. Much research has been,and continues to beundertaken,to understand the fundamentals of plasma discharges. This is such a broad topic due to the very nature and variable dependencies that set the conditions for plasma discharge to occur. This can come in the form of electrode geometry and spacing, dielectric barrier thickness, humidity of environment, material selection for electrodes and dielectric barriers, the power supply used, and the operating gas(es) used. A lot of these influencing factors can be set and kept constant, but still result invariation from system to system. However, the most important aspect comes from the power supply used and the gas(es) employedas the operating environmentfor plasma discharge. The power supply is important as there can be multiple variables applied to generate plasma andvarying each one can havea significant impact on how it behaves. Examples of such parameters include the frequency, duty cycle, voltage, current, and the number of pulses per unit time for the associate power. Gas supplies create the potential for certain chemistries to arise that allow for the processing of many types of samples. For these reasons, it is crucial that diagnostics and monitoring continue to be carried out on the many plasma systems available and currently under development so that the understanding of the multitude of possibilities that arise when using NTP for application purposes can be furthered and set with more confidence. By doing this, not only are the processes and physical properties of plasma better understood, but the mechanisms and reasons for the changes in surface properties, food modification, or biological responses are better elucidated,enablingmore efficient application methods to be developed.