Nuclear fusion in the Sun will create what elements

Nuclear fusion in the Sun will create what elements

Figure 1. The proton-proton fusion process that is the source of energy from the Sun.[1]

The energy from the Sun - both heat and light energy - originates from a nuclear fusion process that is occurring inside the core of the Sun. The specific type of fusion that occurs inside of the Sun is known as proton-proton fusion.[2]

Inside the Sun, this process begins with protons (which is simply a lone hydrogen nucleus) and through a series of steps, these protons fuse together and are turned into helium. This fusion process occurs inside the core of the Sun, and the transformation results in a release of energy that keeps the sun hot. The resulting energy is radiated out from the core of the Sun and moves across the solar system.[3] It is important to note that the core is the only part of the Sun that produces any significant amount of heat through fusion (it contributes about 99%).[3] The rest of the Sun is heated by energy transferred outward from the core.

Steps

The overall process of proton-proton fusion within the Sun can be broken down into several simple steps. A visual representation of this process is shown in Figure 1. The steps are:[4]

  1. Two protons within the Sun fuse. Most of the time the pair breaks apart again, but sometimes one of the protons transforms into a neutron via the weak nuclear force. Along with the transformation into a neutron, a positron and neutrino are formed. This resulting proton-neutron pair that forms sometimes is known as deuterium.
  2. A third proton collides with the formed deuterium. This collision results in the formation of a helium-3 nucleus and a gamma ray. These gamma rays work their way out from the core of the Sun and are released as sunlight.
  3. Two helium-3 nuclei collide, creating a helium-4 nucleus plus two extra protons that escape as two hydrogen. Technically, a beryllium-6 nuclei forms first but is unstable and thus disintegrates into the helium-4 nucleus.

The final helium-4 atom has less mass than the original 4 protons that came together (see E=mc2). Because of this, their combination results in an excess of energy being released in the form of heat and light that exits the Sun, given by the mass-energy equivalence. To exit the Sun, this energy must travel through many layers to the photosphere before it can actually emerge into space as sunlight. Since this proton-proton chain happens frequently - 9.2 x 1037 times per second - there is a significant release of energy.[3] Of all of the mass that undergoes this fusion process, only about 0.7% of it is turned into energy. Although this seems like a small amount of mass, this is equal to 4.26 million metric tonnes of matter being converted to energy per second.[3] Using the mass-energy equivalence, we find that this 4.26 million metric tonnes of matter is equal to about 3.8 x 1026 joules of energy released per second!

For Further Reading

For more information on the energy that comes from the Sun, see:

  • Sun
  • Solar radiation
  • Insolation
  • Solar energy to the Earth
  • Temperature of the Earth
  • Solar power
  • Or explore a random page

References

  1. Wikimedia Commons. (July 30, 2015). Fusion in the Sun [Online]. Available:https://upload.wikimedia.org/wikipedia/commons/0/03/Fusion_in_the_Sun_it.png
  2. Fraser Cain. (July 30, 2015). Fusion in the Sun [Online]. Available: http://www.universetoday.com/18707/fusion-in-the-sun/
  3. ↑ 3.0 3.1 3.2 3.3 Jerry Coffey. (July 31, 2015). How Does The Sun Produce Energy? [Online]. Available: http://www.universetoday.com/75803/how-does-the-sun-produce-energy/
  4. Karl Tate. (July 30, 2015). Proton Fusion, the Sun's Power Source, Explained [Online]. Available: http://www.space.com/26956-proton-fusion-sun-power-source-infographic.html

What does nuclear fusion in the Sun create?

In the core of the Sun hydrogen is being converted into helium. This is called nuclear fusion. It takes four hydrogen atoms to fuse into each helium atom.

What elements does nuclear fusion produce?

DT fusion produces a neutron and a helium nucleus. In the process, it also releases much more energy than most fusion reactions. In a potential future fusion power plant such as a tokamak or stellarator, neutrons from DT reactions would generate power for our use.

What elements are formed in the Sun?

Despite the controversy, everyone agrees on the basics: The sun consists mainly of hydrogen and helium, the two lightest elements. It generates energy at its center through nuclear reactions that convert hydrogen into helium.

What elements are formed during fusion?

Light elements like hydrogen and helium formed during the big bang, and those up to iron are made by fusion in the cores of stars. Some heavier elements like gallium and bromine need something more, such as a supernova.