Fusion: Unlocking the Power of the Sun
Written By Kesavan Rangarajan
You may have heard of nuclear fission, the source of energy for nuclear plants or atomic bombs, but have you heard of nuclear fusion? Stars, the source of all life in the universe, get their perpetual energy from fusion reactions. Fusion reactions are the fusion (I know, crazy) of two atomic nuclei. In an extreme simplification, the nucleus of a hydrogen atom hits the nucleus of another hydrogen atom at an incredible speed. This process releases 2. 8 × 10^12 Joules of energy for each atom and is how the sun will stay alive for BILLIONS of years to come. At the core of the sun, hydrogen atoms move at incredible speeds, making it the perfect location for fusion reactions. The sun fuses around 600 MILLION metric tons of hydrogen into helium every second. That’s enough energy to run the ENTIRE WORLD for 800,000 years! The sun and other stars in the universe have the perfect conditions for nuclear fusion, but bringing this to Earth is a different matter.
In order to produce a fusion reaction, we need two main things. Hydrogen (lots of it) and energy. Hydrogen has many isotopes, or versions, that have different numbers of neutrons. Fusion on Earth requires two specific isotopes, deuterium and tritium. These isotopes are both positively charged, so they tend to repel each other, making the process of fusing these atoms together a lot more difficult. Deuterium is pretty abundant, as it can be found in seawater. Current supplies will last for millions of years. Tritium, on the other hand, can be generated from lithium, which is extracted from the Earth’s crust. However, there is one important thing to mention. The Sun has a far stronger gravitational pull than Earth. Therefore, fusion on the Sun can occur at 15 million °C, while on Earth, it can only occur at 150 million °C (YIKES!).
For almost a century, scientists have been trying to figure out ways to produce this energy. The main hurdle was that hydrogen atoms melted into a mushy plasma at 150 million °C. This led to the idea of a Tokamak, a chamber with an incredibly powerful magnetic field, used to contain this hot plasma. This method was first discovered in the 1950s by the USSR when fusion research was directly linked to the production of atomic weapons. Near the end of the Cold War, the cost and complexity of devices in order to research fusion were too great, leading to international cooperation. The hurdle was that the energy produced did not outweigh the energy used to start the reaction. Following this, many European laboratories joined together to build research laboratories, including ITER, the world’s biggest experiment regarding fusion energy. Following ITER, DEMO, a demonstrational power plant, moves fusion energy from an experiment to a reality.
Fusion energy seems to be a promising, yet ambitious path to our future. It is a clean source of energy, as it does not produce greenhouse gasses or long-term waste, making it one of the best alternatives in the upcoming battle against climate change. Fusion energy has the potential to be far more efficient than fission energy, through its fuel availability, energy production, and its waste production. Even though it is still in development, fusion energy can be the backbone of our future society, and gives us hope towards a promising world.
Works Cited
Bringing the power of the sun to Earth. Fusion for Energy. (2023, August 23). https://fusionforenergy.europa.eu/
Nuclear Fusion Power. Nuclear Fusion : WNA - World Nuclear Association. (n.d.). https://world-nuclear.org/information-library/current-and-future-generation/nuclear-fusionpower.aspx
