What is a Plasma?
Plasma is often referred to as the ‘Fourth State of Matter’ due to its unique characteristics which cannot be solely linked to one of the three states of matter: solid, liquid and gas. Plasma is a partially or fully ionized gas; an array of ions and electrons are present in the gas and their ability to move freely without being attached to an atom or molecule makes the gas electrically conductive. This freedom of movement of the ions and electrons makes plasma highly nonlinear and complex, with the motion of the positive and negative particles being governed by long range electromagnetic interactions. The study of plasma physics is of high interest in the science world as it is estimated that 99% of the visible universe is formed of these ionised gases.
But why is it of interest? Plasmas are responsible for visible phenomena such as lightning, the aurora borealis, 'Northern Lights' etc. Plasmas are also being touted as a possible solution to the energy crisis which we face. This is through fusion reactions in a TOKAMAK. Scientists are excited by this possibility and there is, therefore, a great deal of research opportunities for a budding physicist.
