Plasma
Plasma, the fourth state of matter, consists of electrons, ions and to a large extent also neutral particles. The electrons and ions significantly contribute to the unique properties of plasma vis-à-vis neutral gas. The properties include high electrical conductivity, response to electric and magnetic fields. These and other properties make it best suited for various types of applications – right from high temperature fusion energy to low temperature bio medical.
Laboratory plasmas can be broadly classified into two types: Thermal plasmas and Non-thermal plasmas.
Thermal Plasma
As the name indicates, it has a large heat content and is usually an atmospheric pressure operating system. In thermal plasma, electrons, ions and neutral particles are in same temperature. The temperatures obtained can go from few hundred degrees up to tens of thousands of degrees. This has applications ranging from cutting, welding, spraying, waste treatment, material processing etc.
Thermal plasma waste treatment
(Bharathiar University)
Operation of thermal plasma for synthesis of submicron particles (IPR Gandhinagar)
Plasma spraying to prepare protective coatings (Bharathiar University, Coimbatore)
Non-Thermal Plasma
These type of plasmas has energy in the form other than heat energy. Temperature of the electrons is much higher than that of ions and neutral particles. The bulk temperatures of these plasmas could be as low as room temperature. They typically operates at low pressures. However, atmospheric pressure non-thermal / low temperature plasma can also be created. Non-thermal plasmas are used in applications like fungal treatment on skin, dental treatment processes and also various other material processing like thin film multilayer coatings, ion implantation, waste treatment etc. Several academic and research institutes in India have been working on these plasmas both from fundamental aspect as well as from application point of view.
Glow discharge plasma for surface modification (Bharathiar University, Coimbatore)
Micro plasma for waste water treatment (Bharathiar University)
