What is Plasma?
Often referred to as the “Fourth State” of matter, the other three being solid, liquid and gas, a plasma consists of a partially-ionized gas, containing ions, electrons, and neutral atoms. As a result of these particles in various states of entanglement, some of the free electrons in the plasma allow for current and electricity to flow.
A plasma has characteristics of both gases and liquids – a plasma will move and “flow” like a liquid.
Common examples include lightning, mercury plasma in fluorescent bulbs, plasma displays (TVs and monitors), stars (our sun) and…fusion reactors.
What is Fusion?
Fusion is the process of atoms binding together, or “fusing”, to create new nuclei and release energy, and typically involves the joining of two or more “light” atoms, such as Hydrogen or Helium or Boron.
When these “light” atoms overcome the inherent strong force of repulsion – thereby fusing together – the output is a different atom or isotope AND energy. This formative energy output happens quite simply because of the known relationship between Mass and Energy: E=mc2
Fusion is the same process by which the sun operates: Hydrogen atoms fuse to create Helium and other elements, and in the process produce immense amounts of energy and heat. Fusion is fundamentally opposite from “fission”, which is the method by which current nuclear power plants generate heat for electricity by splitting atoms apart (along with disastrous radioactive byproducts).
Building a Fusion Reactor.
The current challenge for the Fusion Industry field is to break the Hot Enough / Long Enough barrier. In order to reach fusion reaction conditions, the ionized plasma field must be both HOT ENOUGH and the resulting reaction last LONG ENOUGH in order for a meaningful electrical output to be achieved – either through direct conversion to electricity or through converting heat to drive a steam turbine. The industry is currently able to produce reaction temperatures far exceeding that of the sun, but have been unable to capture the reaction long enough to produce useful fusion power. For any fusion process to be meaningful, the amount of energy created must be greater than the input. No project to date has passed this barrier in the race to sustainable fusion.
Our Sun, the largest fusion reactor in our Solar System, is able to fuse light Hydrogen atoms into Helium atoms and other light elements due to its extreme gravity. The inward force of gravity creates pressure conditions that in turn produce extreme heat (15 Million °C). The combination of high pressure and high temperature excites the Hydrogen atoms and isotopes to rapid states of continual bombardment, thereby fusing and releasing energy.
The challenge here on Earth is to mimic these extreme temperatures in a controlled environment. For this reason, Earth-bound fusion has often been referred to as “star in a jar.” Believe it or not, though, the fusion research industry has been able to reproduce fusion temperature conditions far exceeding that of the sun. Target temperatures of 100 Million °C have been reached, so the HOT ENOUGH barrier of fusion appears to have been remedied.
Fusion reactors all have a few parameters in common: they all use some arrangement of magnets – either permanent, electromagnetic, or superconducting. The magnetic forces are used to contain the heated (and subsequently fused) plasma mix. Some solutions rely on colliding plasma beams at speeds upwards of 1 Million mph to generate the heat conditions, while others utilize microwaves to add additional heat energy to the plasma. One of the main difficulties with plasma is that it tends to exhibit “instabilities”, which are among the main reason such extreme temperatures and confinement procedures are necessary in the current design paradigm.
To date, fusion moments are brief and elusive, and no effort – whether private, university, or government funded – has been able to produce a net electricity output greater than electricity input. As one can imagine, it takes a lot of electricity to super-heat a plasma and to contain it with superconducting magnets (which, although more efficient than their electromagnetic cousins, still require cooling to -200 °C to keep them functioning).