Who Discovered Nuclear Fusion and How does fusing two atomic nuclei into one atom release energy?

Fusion energy is the power of the sun. It is a virtually unlimited power source that can be created from hydrogen and lithium, common elements in the earth’s crust.

Fusion is clean, environmentally friendly, and non-polluting. Fusion was theorized in the late 1910s and the 1920s. It was mathematically described in the 1930s. It was finally discovered (demonstrated in the lab) in 1951. Fusion’s technology was turned into the hydrogen bomb shortly thereafter.

But fusion has not yet been converted into its promised practical reality. It still works only in the lab. If this discovery can be converted into a working reality, it will end energy shortages for thousands of years.

Scientists had always thought that the sun produced heat and light by actually burning its own matter through normal combustion. In the nineteenth century, a few scientists (most notably British Lord Kelvin) argued that the sun could create heat from its own gravitational collapse, but that such a process could only last for a few million years.

Einstein’s famous 1905 equation (E = mc2) allowed scientists to realize that even tiny amounts of matter could be turned into tremendous amounts of energy. In 1919 American astronomer Henry Russell described the physics and mathematical processes that would allow the sun to fuse hydrogen atoms into helium atoms and release vast amounts of energy in the process. The process was called fusion. This theory of how the sun works was confirmed in 1920 by astronomer Francis Aston’s measurements.

The theory of fusion existed. But was fusion something that could be practically developed on Earth? In 1939 German physicist Hans Bethe described, in mathematical detail, the theory of how to create a fusion reaction on Earth. But there was a problem. Bethe’s equations said that hydrogen atoms had to be raised to a temperature of over 100 million degrees C (180 million°F) and had to be squeezed into a small space so that the protons in hydrogen nuclei would collide and fuse into helium nuclei. There was no known material or force that could accomplish such a feat.

Dr. Lyman Spitzer founded the Princeton University Plasma Physics Lab in 1948. He soon realized that the only way to contain a fusion reaction was with a high-energy magnetic field. He surrounded a donut-shaped tube that contained hydrogen gas with coils of wire to create a magnetic field that kept hydrogen atoms trapped while lasers heated them many millions of degrees.

But there was a problem. When he looped thousands of loops of wire down through the middle of the donut and up along the outside, it naturally packed the wires more densely on the inside of the donut than on the outside. That created a stronger magnetic field on the inside (center) of the donut-shaped tube than on the outside. Hydrogen atoms were pushed to the outside and flung at near light speed out of the tube. The fusion generator didn’t work.

Then Spitzer discovered a marvelous remedy. He twisted the donut containing his hydrogen gas into a figure eight. As hydrogen sped through this looping tube, it spent part of each lap near the inside of the figure eight and part near the outside and so was kept from being pulled out of the tube by variations in the magnetic field

In 1951 Spitzer completed work on this first hydrogen plasma fusion generator. He called it a stellarator, since it was like creating a star, and fired it for the first time for only a small fraction of a second, still not sure that superheated hydrogen plasma wouldn’t turn into a hydrogen bomb.

For one glorious half-second the donut-shaped mass of gas blazed supernova bright, like a blinding sun burning at 70 million degrees Fahrenheit. Unimaginably bright and hot, the gas became a two-foot diameter, seething, explosively powerful pool of hydrogen plasma. Then it faded to dull purple, and, two seconds after it first ignited, turned back to black.

For one flickering moment, Lyman Spitzer had created a new star, almost. More important, he had discovered that fusion was possible on Earth.

As an alternative energy source, fusion has many advantages, including worldwide long-term availability of low-cost fuel, no contribution to acid rain or greenhouse gas emissions, no possibility of a runaway chain reaction, by-products that are unusable for weapons, and minimum problems of waste disposal.

About Karen Hill

Karen Hill is a freelance writer, editor, and columnist. Born in New York, her work has appeared in the Examiner, Yahoo News, Buzzfeed, among others.

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