Fueling the Future: Exploring the Depths of Nuclear Fusion Technology

A deep dive into what is nuclear fusion, how DeepMind has trained an AI to control nuclear fusion, what is means for the future of energy and its current applications.

What Is Fusion Technology? 🌈

Nuclear fusion is a process where two lighter atomic nuclei combine to make a heavier one while releasing massive amounts of energy. Fusion reactions take place in a state of matter called plasma — a hot, charged gas made of protons (positive ions) and free-moving electrons with unique properties distinct from solids, liquids or gases.

This process is what powers our sun and other starts. In the sun, the process of fusion happens when tiny particle centers, called nuclei, slam into each other at incredibly hot temperatures — roughly 10 million degrees Celsius. This extreme heat supplies them with a lot of energy, enabling them to conquer their natural push away from each other due to their electric charges, otherwise known as their mutual electrical repulsion. When these nuclei get really close to one another, an even stronger force that operates inside the nuclei takes over — it’s like a magnet that pulls them together — and this force beats the push from their charges. To make this fusion more likely, the nuclei must be kept close together, so they have a better chance of crashing into each other. In the sun, the fusion conditions are created by the tremendous squeeze from the sun’s powerful gravitational pull.

Since the 1930s, scientists has long grappled with the concept of nuclear fusion, they, along with engineers, have been striving to recreate and control this process.

But why is this research ongoing for over 100 years?

If we can mimic nuclear fusion here on Earth on a large scale, it has the potential to offer abundant, clean, safe, and inexpensive energy to meet the world’s needs.

Compared to fission (used in nuclear power plants), fusion could yield four times more energy per unit of fuel and nearly four million times more energy than burning oil or coal.

The majority of fusion reactor designs currently in progress involve using a mix of deuterium and tritium, which are types of hydrogen atoms with extra particles. Theoretically, just a small amount of these substances — a few grams — could generate a terajoule of energy.

To put that in perspective, this is roughly the amount of energy an individual in a developed country consumes over sixty years.

Heard of Einstein’s famous equation, energy = mass times the speed of light c squared.

E = mc²

the equation reflects how a very small amount of mass may be converted into a very large amount of energy — i know, the magic of exponents. If we mix 2 kg of deuterium with 3 of tritium, roughly 20 grams of mass would become other forms of energy

E =(0.02) x (9 * 1⁰¹⁶)

the different between the reactants and the products would release the following amount of heat which would be enough to power 50,000 homes for a year.

E = 1.8 x 10¹⁵ Joules

Fusion fuel is abundant and easy to obtain. Deuterium can be taken from seawater at a low cost. Tritium can be created by the interaction of fusion-generated particles with abundant lithium. Of which these fuel sources would be sufficient for millions of years.

Forthcoming fusion reactors are inherently secure and would not generate highly radioactive waste that persists for a long duration, in contrast to other energy production methods. Moreover, these reactors are designed to be intrinsically safe and have no risk of an uncontrolled reaction or meltdown. Fusion can only happen under precise operational conditions. If those conditions are not met, for example, if there is an accident or system malfunction — the fusion process naturally ceases. This ensures that the energy dissipates quickly, and any potential harm to the reactor is minimized. Similar to fission, nuclear fusion doesn’t release CO2, which is a potent greenhouse gas that contributes to climate change into the atmosphere. As a result, it has the potential to provide sustainable, low-carbon electricity from the latter half of the 21st century onwards.

So Why Aren’t We Using Fusion on a Mass Scale? ❓

While the sun’s massive gravitational force naturally induces fusion, without that force a temperature even higher than in the sun is needed for the reaction to take place. In other to mimic the process that works inside stars, it would require intense gravity to force this together. But we can do the same job using heat, however, on Earth, we need temperatures of over 100 million degrees Celsius to make deuterium and tritium fuse, while regulating pressure and magnetic forces at the same time, for a stable confinement of the plasma and to maintain the fusion reaction long enough to produce more energy than what was required to start the reaction. These conditions are much harder to achieve and maintain compared to the conditions naturally present in the sun, where fusion occurs due to its massive gravitational force

One way scientists have tried to recreate nuclear fusion involves a tokamak — a doughnut-shaped vacuum chamber that uses powerful magnets to turn fuel into a superheated plasma — between 150 million and 300 million degrees Celsius — where fusion may occur.

Major Breakthroughs? 🤯

Here are some major breakthroughs in fusion technology:

• In December 2022, US scientists announced a major breakthrough in nuclear fusion science. They produced more energy from a fusion experiment than was put in, which is a significant step towards creating energy from nuclear fusion
• In February 2022, European scientists at the UK-based JET laboratory smashed their own world record for the amount of energy they can extract by squeezing together two forms of hydrogen. This puts them a step closer to fusion power.

Startups in the Space ⭐️

Helion Energy is a private company that is working to build the world’s first fusion power plant, using a new method called plasma acceleration. This method involves heating fuel to 100 million degrees using a 40-foot device called a plasma accelerator, which compresses the fuel to fusion conditions and then expands it to recover the energy to produce electricity. Helion’s technology is intended to be faster and more straightforward than traditional nuclear fusion methods. The company’s technology uses deuterium, found in water, and helium-3, a product of fusing deuterium atoms, to produce energy. Experts have expressed doubts about Helion’s timeline for commercializing its technology, with some estimating that it could take several decades to achieve. However, Helion is committed to building a fusion system and selling it commercially to Microsoft, which recently made a binding agreement with the company.. If successful, Helion’s fusion power plant could be a major step towards achieving unlimited clean electricity

MIT and a newly formed private company called Commonwealth Fusion Systems (CFS) launched a novel approach to fusion power in 2018. The goal of the project is to build a compact device capable of generating 100 million watts of fusion power, which could demonstrate key technical milestones needed to ultimately achieve a full-scale prototype of a fusion power plant that could set the world on a path to low-carbon energy. The collaboration between MIT and CFS is expected to bolster MIT research and development in fusion power. In 2021, scientists at MIT and CFS achieved a major advance toward fusion energy by developing a new magnet that enables a much stronger magnetic field in a smaller space. With the magnet technology now successfully demonstrated, the MIT-CFS collaboration is on track to build the world’s first fusion device that can create and confine a plasma that produces more energy than it consumes. The major innovation in the MIT-CFS fusion design is the use of high-temperature superconductors. The long-term goal of the project is to introduce fusion power into the energy market in time to help combat global warming.

DeepMind, a subsidiary of Alphabet (Google’s parent company), has developed an artificial intelligence (AI) system that can control nuclear fusion reactors. The AI system uses a deep reinforcement learning algorithm to autonomously control the magnetic fields that contain the plasma inside a tokamak fusion reactor. This breakthrough has the potential to accelerate the development of nuclear fusion as a practical power source. Controlling nuclear fusion is a complex task because the plasma state is constantly changing and cannot be continuously measured, making it an “under-observed system”. DeepMind’s AI system overcomes this challenge by learning to control the 19 magnetic coils inside the tokamak reactor through trial and error in a simulator

The system can manipulate the plasma into new configurations that can produce higher energy, which were previously difficult to attempt using traditional control methods. They collaborated with the Swiss Plasma Center at the Swiss Federal Institute of Technology in Lausanne (EPFL) and researchers successfully demonstrated how the AI system can autonomously control the magnetic coils and contain the plasma in the tokamak, opening new avenues for advancing nuclear fusion research. This achievement by DeepMind represents a significant step forward in the quest for practical fusion power as they focused on controlling the plasma inside the tokamak reactor, however, does not directly target the hurdles of achieving sustained fusion reactions or commerical-scale power generation through this technology.

What Now? 🤔

• Technological advancements: New technologies such as high-temperature superconductors and 3D printing provide exciting opportunities to build small fusion devices.
• Timescales: Experts mostly agree that if a pilot plant that works is developed by the end of the 2030s, it would be a significant achievement. However, fusion energy is not expected to be viable in the next 10 to 20 years
• Economics: Beyond the engineering and technological challenges, economics will play a key role in shaping fusion energy’s future. The niche for fusion in the US depends not only on the price of building a reactor but also on the energy mix of the future grid and the cost of competing technologies like nuclear fission