Nuclear fusion aims to release energy, in a process similar to that of the sun, at a commercially-viable cost, safely and without the production of large amounts of harmful long-life waste products. The process has been under active scientific development for 50 years and is anticipated to become a viable source of energy by 2050.
Recent trials of high power lasers to produce a continuous fusion reaction have been very promising.
Principle of Operation
If two suitable light nucleotides are forced to fuse under extreme conditions of temperature and pressure, a single heavier nucleotide is produced, and a very large amount of energy may be released. The feasibility of energy release by nuclear fusion is relatively easy to demonstrate on a small scale, but has proved to be very difficult to achieve commercially.
The nucleotides are produced as a gas plasma. A large electric current is passed through the plasma, which is thus heated to a very high temperature. The plasma is contained under pressure by an intense magnetic field, which is produced by a superconducting electromagnet. The plasma may not be allowed to come into contact with the containing vessel, as this would lower the temperature of the plasma.
An alternative process uses multiple high-power lasers, focussed upon the fuel element, to produce fusion.
Work is in progress, with experimental reactors planned or in construction, in the USA, Russia, China and Europe (France).
It is understood that continuous energy production was achieved for periods as long as 100msec in 2007. The experimental reactor now in construction (the I.T.E.R. Project) is expected to produce continuous energy output, and to solve the metallurgical problems of containing the high temperature plasma. The next step will be to build prototype reactors, in order to establish the design of commercial reactors.
Although general information about the I.T.E.R. Project is readily available through the internet, much of the new design work is generating valuable technical property which is generally not available in the public domain.
Meanwhile, in late 2014, the Skunk Works research facility of Lockheed Martin in U.S.A. announced that they had invented and patented a new design of magnetic plasma containment device, of radically smaller size. This, they claimed, because of its small size, would enable construction of a protoype of the device by the end of 2015. They forecast production of small commercial reactors, portable on a railcar, within 10 years. Skunk Works has a creditable history of achievements, but the scientific community has a mixed opinion. Time will tell!