What is nuclear fusion and why the hype?

Nuclear fusion describes the physics of two or more atomic nuclei fusing together to create larger elements – the type of process that occurs in our own Sun.

The reason this is such an exciting prospect in power generation is that such atomic fusion can release large amounts of energy. If we can harness this release of energy, humanity could potentially gain access to an abundant and inexhaustible source of largely sustainable energy.

For now, such achievement is still a long way off, but researchers around the world are constantly advancing the field, making incremental improvements that are slowly bringing us closer to that goal.

How does nuclear fusion work?

Atoms grow as protons come together in larger and larger groups, linked by strong nuclear force. This attraction results from the interactions between their trios of constituent particles, called quarks.

Thanks to Coulomb’s force – the force of attraction or repulsion between particles due to their electrical charge – protons tend to stand a fair distance from each other – far too far away for the nuclear force to be able to. grab them.

Neutrons, on the other hand, have no charge and therefore are not repelled, allowing them to move relatively close to other nuclear particles with little effort. Thanks to subtle differences in a property called spin, neutrons and protons close together can stick together to form a single atomic nucleus.

In theory, a proton associated with a neutron can bind to another proton-neutron partnership, with the neutrons acting as a kind of mediator. But getting several protons together enough for the powerful force to take over is no easy task. Even relatively simple fusions between two atoms of deuterium (hydrogen made up of a proton and a neutron) to form a helium-3 atom require the kind of pressure found in the hearts of objects like our Sun.

For even larger elements to emerge, like those the size of carbon, these pressurized furnaces would have to withstand temperatures of at least 100 million degrees Kelvin – six times hotter than the core of the Sun.

The fusion of nuclei into even heavier elements, on the scale of gold and uranium, requires a degree of cosmic power. Think about the types of forces that are found in collisions of neutron stars or in certain supernovas.

How does nuclear fusion generate energy?

The production of fusion energy depends on the differences in the amount of energy required to hold nuclear particles together.

If you take an alpha particle – a pair of protons and a pair of neutrons grouped together – and weigh it, you’ll get a mass of 4.00153 units. Weigh each atom individually, however, and the total sum would be 4.03188 units.

Using the equation “energy = mass x square of the speed of light” (yes, that’s E = mc²), the difference in mass is also a difference in energy. Bound together, the collection of particles has less energy than when they are separated; therefore, when they merge, this reserve energy is released into the world.

Forged deep within the Sun, this energy slowly travels to the surface, where it is emitted in the form of waves in the form of electromagnetic radiation or sunlight.

Here on Earth, physicists and engineers have developed various devices that could help us capture and use the energy released by nuclear fusion. When they do, you’ll be sure to hear about them.

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