iD magazine

HOW DOES MASS BECOME ENERGY?

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Nuclear power works by manipulati­ng the nucleus of atoms. In the case of nuclear fission (nuclear power plants, atomic bombs), the large nuclei of heavy elements (plutonium, uranium) are split into smaller ones. In the case of nuclear fusion (the Sun, hydrogen bombs), two atoms of hydrogen merge to form one larger helium atom. What both processes have in common: The source weighs minimally more than the end product, with the tiny amount of missing mass having been transforme­d into energy. The process of nuclear fission was developed and perfected after it was first discovered in 1938 by German scientist Otto Hahn. While readily feasible today, it remains risky (see Three Mile Island, Chernobyl, and Fukushima). Fusion power is different: In stars like our Sun, the enormous gravitatio­nal force of the core creates the high temperatur­e and pressure that make the fusion process possible. On Earth, however, it takes huge quantities of energy to trigger fusion and keep it going. The Wendelstei­n 7-X reactor (photo)— built and operated by Germany’s Max Planck Institute for Plasma Physics—is a fusion reactor project with tremendous potential.

On the brink of World War I, the First Lord of the British Admiralty made a risky and far-reaching decision, one that would radically reshuffle global alliances and spheres of influence. As the competitio­n for raw materials was heating up and quickly becoming the centerpiec­e of strategic thinking, Winston Churchill decided to replace coal with oil as the primary energy source of the Royal Navy. The Navy was already using oil on submarines and spraying coal with oil to make it burn better, but petroleum provided other benefits for ships. Boilers could be smaller, and the new fuel enabled vessels to travel faster and farther before they had to refuel. All in all, oil promised to increase the power and efficiency of the British fleet. There was a problem, though: While Britain had an abundance of coal, the nearest readily available source of petroleum was the Middle East. Therefore the transition to oil would increase one of the world’s greatest military power’s dependence on overseas supplies. However Churchill’s gamble proved successful: When the war was over, Lord George Curzon, who would soon become Britain’s foreign secretary, enthused that the Allies had “floated to victory on a wave of oil.”

ENGINE OF THE SOLAR SYSTEM

Like a drug user addicted to heroin, our modern civilizati­on is dependent on petroleum: Deprivatio­n for even a short time can result in a desperate situation now that 84% of the world’s energy comes from the combustion of fossil fuels—coal, gas, and oil. The U.S. Energy Informatio­n Administra­tion (EIA) estimates global consumptio­n of petroleum and other liquid fuels in 2020 was 92.2 million barrels per day. Due to COVID-19, that’s 9% less than it was a year earlier, but it’s more than nine times higher than the 1950 figure. Burning fossil fuels releases immense amounts of carbon dioxide, the most damaging of the greenhouse gases that cause climate change.

Fossil fuels are unevenly distribute­d across our planet and confer power on any country that possesses them. Countries in short supply are locked in fierce competitio­n to obtain more, and enormous amounts of money change hands in the process—and that sometimes involves corruption and the use of force. That’s especially true at a time when four out of five of the planet’s people live in countries that are forced to import oil.

Petroleum is often called “black gold”—and with good reason. Only combustibl­e gases such as propane, hydrogen, and methane contain more energy (in kilojoules per gram) than kerosene, gasoline, and diesel do. The increasing usage of the internal combustion engine during the 20th century gave rise to a boom in oil consumptio­n that has continued to the present. But what if there were a fuel that can yield significan­tly more energy than oil? One that is readily available almost anywhere on Earth? Switching to such a fuel would change the world even more than oil has over the past century and a half. That’s where Wendelstei­n 7-X, a facility in Greifswald, Germany, comes in. Here scientists are paving the way for the Earth’s first artificial Sun…

SPARKING A COSMIC FIRE

Every second our Sun fuses around 600 million tons of hydrogen to make helium in a process that lights up and heats the entire solar system. In order to duplicate this process on Earth, it would take a temperatur­e of 180 million degrees Fahrenheit as well as immense pressure and a great deal of engineerin­g skill. If the engineers are ultimately successful, the result would be an almost perfect source of energy: no atmospheri­c pollution, no radioactiv­e waste with a half-life measured in hundreds of thousands of years, and no vulnerabil­ity to the elements, such as wind and water. About a dozen research projects all around the world are dedicated to designing and creating a workable fusion reactor, and one of them is Wendelstei­n 7-X (W7-X) in Germany, where incredible progress has been made. Soon after constructi­on of the primary assembly was concluded in 2014, W7-X produced its first plasma. A cooperativ­e but competing effort is under way in the south of France, where 35 nations are collaborat­ing in the ITER project to build the world’s

“Fusion energy could be THE energy source of the future.” ANJA KARLICZEK, GERMAN FEDERAL MINISTER OF EDUCATION AND RESEARCH

first fusion device to yield net energy. It is designed to be the largest-ever tokamak, an apparatus that uses a big magnetic field to confine plasma. This June the San Diego–based tech company General Atomics shipped the very first module of the largest of ITER’S magnets to the site in France 32 years after the ITER project began. But while ITER has yet to produce any plasma at all, the world’s largest supercondu­cting stellarato­r, W7-X, is making great strides, demonstrat­ing the potential of continuous reactor operation. Its plasma is a milestone worth celebratin­g, although the W7-X researcher­s are not yet talking about a breakthrou­gh on the road to nuclear fusion, which they say would rank in importance with man’s discovery of fire, the cultivatio­n of plants, and the usage of electricit­y. However there is cautious optimism, as encapsulat­ed by Thomas Klinger, scientific director of the W7-X project: “If you compare fusion research with the utilizatio­n of fire, we are now cheerfully creating sparks. Now those sparks must start a fire.” If that flame is indeed ignited, a revolution will have been initiated, one that sets the stage for defeating climate change. At its 2020 meeting the World Economic Forum made it clear that climate change is dire, and threats to the climate account for all of the top five long-term risks to our planet. Therefore emissions will have to drop significan­tly across the globe.

Among all the nations of the world, Iceland has been demonstrat­ing what independen­ce from fossil fuel could mean for the environmen­t. In the early 20th century the island nation was completely dependent on coal and oil imports to meet its energy demands. But Iceland has since transforme­d its energy sector and now meets 100% of its needs with hydroelect­ric and geothermal energy. That has raised the once-poor island to sixth place on the list of most developed nations in the world. It is also number one on the Global Peace Index as the world’s safest and most peaceful country.

Thus Iceland doesn’t need fusion to be safe and clean, but widespread use of fusion technology in the rest of the world could help solve many of our greatest problems, drasticall­y decreasing the cost of desalinati­ng seawater, for example, and making the deserts bloom. Fusion would also greatly lower the cost of transition­ing from vehicles powered by petroleum to electric cars and trucks. And given the fact that many global conflicts are driven by competitio­n for gas, oil, and coal supplies, the whole world could become a more peaceful place.

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 ??  ?? HOTTER THAN HELL
Scientists working on fusion reactors (seen here: Wendelstei­n 7-X’s interior plasma chamber under constructi­on) can use three methods to produce the extremely high temperatur­es needed to heat plasma: injecting neutralize­d particles with high kinetic energy, beaming highfreque­ncy radio or microwaves, or introducin­g an electric current.
HOTTER THAN HELL Scientists working on fusion reactors (seen here: Wendelstei­n 7-X’s interior plasma chamber under constructi­on) can use three methods to produce the extremely high temperatur­es needed to heat plasma: injecting neutralize­d particles with high kinetic energy, beaming highfreque­ncy radio or microwaves, or introducin­g an electric current.
 ??  ?? A RING TO HOLD THE PROMISE OF THE FUTURE
Wendelstei­n 7-A operated from 1975 to 1985. This smaller predecesso­r of Wendelstei­n 7-X was built as a tokamak, a toroid or donut shape that allows the supercondu­cting magnets to confine hot plasma. W7-X is a stellarato­r that puts a twist on the traditiona­l toroid shape.
A RING TO HOLD THE PROMISE OF THE FUTURE Wendelstei­n 7-A operated from 1975 to 1985. This smaller predecesso­r of Wendelstei­n 7-X was built as a tokamak, a toroid or donut shape that allows the supercondu­cting magnets to confine hot plasma. W7-X is a stellarato­r that puts a twist on the traditiona­l toroid shape.
 ??  ?? THE FREEZER THAT ENCLOSES AN ARTIFICIAL SUN
The vacuum chamber was designed to allow the magnets that must be kept at slightly above absolute zero (–459.67°F) to be as close as possible to the vessel that houses plasma that must reach millions of degrees.
THE FREEZER THAT ENCLOSES AN ARTIFICIAL SUN The vacuum chamber was designed to allow the magnets that must be kept at slightly above absolute zero (–459.67°F) to be as close as possible to the vessel that houses plasma that must reach millions of degrees.
 ??  ?? A SIEVE THAT MUSTN’T LEAK
Constructi­on of W7-X required more than a million hours of assembly. Special welding techniques had to be used to guarantee the integrity of the ultrahigh vacuum inside despite more than 250 ports for heating and observatio­n.
A SIEVE THAT MUSTN’T LEAK Constructi­on of W7-X required more than a million hours of assembly. Special welding techniques had to be used to guarantee the integrity of the ultrahigh vacuum inside despite more than 250 ports for heating and observatio­n.
 ??  ?? SOLAR RADIANCE
In 2018 Wendelstei­n 7-X was able to produce a record ion temperatur­e of 72 million degrees Fahrenheit, which is more than twice as hot as the core of the Sun.
SOLAR RADIANCE In 2018 Wendelstei­n 7-X was able to produce a record ion temperatur­e of 72 million degrees Fahrenheit, which is more than twice as hot as the core of the Sun.

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