ABSTRACT
The concept of plasma was introduced by Tonks and Langmuir (1929a, 1929b, 1929c). Plasma is defined as a state where a significant number of atoms and/or molecules are either electrically, thermally or magnetically charged or ionised. Plasma in general refers to the excited gaseous state consisting of atoms, molecules, ions, metastables, and excited state of these as well as electrons, such that the concentration of positively and negatively charged species is roughly the same. The ionised gas system displays significantly different physical and chemical properties when compared with its neutral condition. Theoretically, plasma is referred to as a “fourth state of matter” and is characterised in terms of the average electron temperature and the charge density within the system (Clark, Dilks, and Shuttleworth 1978; Chan 1994; Kan, Chan, and Yuen 2000).
