Nuclear Fusion: What You Should Expect about Nuclear Fusion

Nuclear Fusion

What is Nuclear Fusion?

Nuclear Fusion Reaction means the reaction created by the collision of two smaller nuclei to form a one-atomic nucleus. This reaction releases a large amount of energy. To perform this reaction lightweight elements such as H2 (Hydrogen)and He (Helium) are used. Most commonly the isotopes of Hydrogen (Deuterium, and Tritium) are used for this. 

The reason for this is the reaction between these two isotopes takes place at a lower temperature than other fusion reactions. And this also releases a large amount of energy. Other stars including the Sun, also get power from the energy produced by these nuclear fusion reactions, The energy required for all life functions on earth is obtained because of the energy produced by these nuclear fusion reactions.

How does nuclear fusion work?

Nuclear fusion is one of the simplest and most powerful processes in the universe. Here, two nuclei must collide for this reaction to occur. Even in light elements, the reason that prevents an atomic nuclear reaction is the repulsive force between two atomic nuclei, and the repulsive force is known as the Coulomb force. 

When two Hydrogen atoms come close to each other, repulsion occurs due to the presence of protons in the hydrogen nucleus, that is because the nucleus is positive (+). It is simply as same as the repulsion of two similar poles of two magnets. But because the nucleus has a type of attractive energy, the nuclei could stick together. But for that to occur, the two nuclei must be very close to each other.

If there is a condition where the nuclei can come within a close range of each other, i.e., if there is a high temperature and pressure, the nuclear attraction force is stronger than the repulsion force and allows them to come closer to each other. Because light nuclei are very small, the attraction force of nucleons is felt very strongly in a very small range. 

It is strong enough to feel the Coulomb force. Therefore, when two energetic atoms collide, one large atom is created, and the amount of energy produced is very large. The reason for this large energy difference is the mass difference between the reactant and the product. That is, the mass of the larger nucleus resulting from the result is less than the sum of the masses of the two original nuclei. This remaining mass is released as energy. 

According to Scientists, The reason for this mass difference is that the reaction causes a change in the bond strength between the nuclei. Einstein’s equation E=mc2, which shows the relationship between mass and energy, clearly shows how this remaining mass becomes energy.

Deuterium And Tritium Fusion Reaction
Deuterium And Tritium Fusion Reaction

Nuclear fusion on the sun

As mentioned above, for this reaction to take place between two nuclei, there must be very high pressure and high temperature to overcome the repulsive force and bring them together. This high temperature and pressure situation are present in the core of other stars including the Sun. The pressure in the core of the Sun is billions is about 265 bars (Atmospheric pressure of the earth is approximately 1 bar).

The temperature of the core of the sun is about 15 million degrees Celsius. Due to these conditions, a fusion reaction can be easily maintained in the core of the sun. That is, the hydrogen and helium in the core of the sun are easily fused. The remaining mass is converted into energy and provides the necessary power to the sun.

Nuclear fusion on the sun

Nuclear fusion For Energy

Various research has been done since 1940 to recreate this process that occurs naturally in other stars including the Sun. The method of generating electricity using the energy (heat) produced by nuclear fusion reactions is called fusion power. Devices made to use the energy produced by this fusion reaction are called fusion reactors. 

The fuel used in nuclear fusion (tritium, deuterium) needs high temperature and pressure to create a plasma where fusion can take place. Often the fuel must be heated up to 100 million ‘C. It is approximately 7 times the temperature of the Sun’s core and this is clearly the biggest challenge. 

The commonly used deuterium can be extracted from seawater and tritium can be made from lithium. When the fuel is heated to 100 million ‘C, a fully ionized gas plasma is formed. (A plasma is an ionized gas that conducts electricity.) Scientists follow 2 methods to achieve nuclear fusion. 

They are called Inertial confinement and Magnetic confinement. In inertial confinement, a small (10 milligram) spherical pellet of fuel is compressed and heated to a high density to generate nuclear fusion power. Here, lasers and ion beams are used to compress and heat the fuel to a high density.

The Joint European Torus (JET) magnetic fusion experiment in 1991
The Joint European Torus (JET) magnetic fusion experiment in 1991

The National Ignition Facility (NIF) of the United States of America can be pointed out as the largest inertial confinement fusion experiment. Magnetic confinement fusion (mcf) is a method that uses electromagnetic fields to contain fuel in the form of plasma and generate nuclear fusion power. One of the most prominent options is the tokamak reactor. The tokamak has become a dominant type of fusion reactor around 2016. 

Joint European Torus (JET), the mcf exp experiment of the Culham center for fusion energy, which is located in the United Kingdom, and ITER in Saint-Paul’s Durance which is in France are the world’s most powerful magnetic confinement fusion experiments. They were built on the design of Tokamak. It was reported that on the 21st of December using deuterium and tritium they were able to surpass their last record. When compared to nuclear fission, nuclear fusion is more favorable. 

It can be pointed out that the number of radioactive materials produced is reduced, the number of greenhouse gases is reduced, and the safety and the release of energy are three to four times more than the energy released by nuclear fission through nuclear fusion. However, the temperature and the pressure needed to this process is huge. According to the calculations, this process is economically difficult to perform. If scientists overcome this challenge, this will be the most suitable solution for the future world’s energy problem.