Our story starts in the year 1905(1). During this year Albert Einstein came out with his famous equation E=mc2. The significance of this equation is that it related mass to energy. It showed that massive amounts of energy were stored in the form of mass. In 1920 Francis W. Aston was able to precisely measure the atoms masses of hydrogen nuclei and helium nuclei and show that four hydrogen nuclei are heavier than a helium nucleus (2). In that same year Arthur Eddington suggested that the difference in mass between the helium nucleus and hydrogen nuclei could be the fuel that powers our sun. The quantitative version of this theory was latter developed by Hans Bethe and came out in 1939. In 1932, Ernest Rutherford began nuclear experiments with a particle accelerator (2). Rutherford’s student Mark Oliphant was the first to directly demonstrate fusion in a lab using deuterium and discovering helium-3 and tritium (3).
Fusion research really started to kick off in the 1950s. In 1952 the first H-bomb “Ivy Mike” was created marking the first thermonuclear weapon (2). In 1951 the tokamak was proposed my Soviet Scientists Andrei Sakharov and Igor Tamm (1). The tokamak is a device that uses magnetic fields to confine plasma so that the plasma is in the shape of a torus (a donut shape). This kind of confinement prevents the plasma from coming into contact with the outer confinement chamber so that the chamber doesn’t melt from the temperature of the plasma. Another magnetic confinement method for plasma is the stellarator developed in 1951 by Lyman Spitzer. In 1969 with the results from the T-3 tokamak it was apparent that the tokamak system is much more efficient method of producing a fusion and scientists have been working on it ever since.
Figure 1. Tokamak
Figure 2.Stellarator
In the 1970s laser was invented and scientists started working on Inertial confinement fusion (ICF). KMS Fusion became the first company to demonstrate laser-induced fusion (2). This set the precedent for a new branch of nuclear fusion.
As of now several big tokamaks have been built, these includes JET in Europe, MAST in the UK, TFTR at Princeton (4). The field of fusion is immensely complicated and there is still a long way to go before we can start using it as a source of energy.
Reference:
1. Shukla, Padma Kant. A Brief History of Controlled Thermonuclear Fusion. 2011, indico.ictp.it/event/a10172/session/69/contribution/40/material/0/1.pdf.
2. “Timeline of Nuclear Fusion.” Wikipedia, Wikimedia Foundation, 5 Mar. 2021, en.wikipedia.org/wiki/Timeline_of_nuclear_fusion.
3. EUROfusion. “Research for Tomorrow’s Energy Supply.” Eurofusion, www.euro-fusion.org/fusion/history-of-fusion/.
4. “Nuclear Fusion Power.” Nuclear Fusion : WNA – World Nuclear Association, www.world-nuclear.org/information-library/current-and-future-generation/nuclear-fusion-power.aspx#:~:text=The%20ITER%20(International%20Thermonuclear%20Experimental,due%20for%20completion%20in%202030.
