As human population increases, the need for generating renewable energy has also increased. In order to meet the energy requirements of the future, scientists have been trying to perfect Nuclear Fusion, if perfected nuclear fusion has the potential to fulfill most of our energy needs. Nuclear fusion is the process of generating energy by joining two nuclei of atoms that result in a larger nuclei. Nuclear fusion is the same reaction which generates energy on stars including our own Sun. The Sun has extreme temperature and pressure at its core which allows nuclear fusion to take place.[1] While there is a constant nuclear fusion reaction taking place on the Sun, replicating the same process here on earth is quite an expensive and difficult task.

An important factor that is used to express the efficiency of nuclear reactions is called the Lawson Break Even Condition[2]. Nuclear fusion among atoms can take place in three different types of fusion reactions, which are Proton-Proton Chain, Deuterium-Deuterium, and Deuterium-tritium reactions. There are two feasible methods of nuclear reaction, Magnetic confinement and second called the inertial confinement method.

Types of Nuclear Reactions

edit

There are three types of nuclear reactions, one of which is happening on stars namely the Proton-Proton Chain reaction. Consequently, the other two forms of nuclear reactions, Deuterium-Deuterium and Deuterium-Tritium are more feasible here on earth. These two forms of nuclear reactions are completed through magnetic confinement and inertial confinement methods.

Deuterium-Tritium Fusion[3]

edit

Deuterium-Tritium reaction has the most potential when it comes to yielding energy. The particles involved in this reaction are abundant in their nature as well. In a Deuterium-Tritium Fusion reaction the nuclei of Deuterium and Tritium try and fuse together while being repelled by electric forces.

 
Deuterium and Tritium Fusion
 
Animation of Deuterium and Tritium Fusion

The nuclear reaction can be represented as the chemical equation:

 

Deuterium-Deuterium Fusion[3]

edit

A deuterium-deuterium fusion is another form of nuclear fusion which can be used to generate energy. Unlike the deuterium-tritium fusion, In a deuterium-deuterium fusion, two of the same nuclei of Hydrogen are used.

Chemical Formula:

 

 
Tokamak Fusion Reactor Torus

Methods of Fusion Reaction (Confinement)

edit
 
Inertial Confinement Fusion

There are mainly two methods of Nuclear Reaction that is taking place in labs today. These confinement methods are Magnetic Confinement and Inertial Confinement. Both of the methods have their benefits and drawbacks. As we have discussed before, fusion reaction takes place on stars and their cores. As one can imagine these reactions reach extremely high temperatures because of pressure and the heat generated. To recreate fusion reaction, a huge amount of heat is needed. The temperatures are so high in a nuclear reaction that the plasma generated by the reaction cannot be contained in a traditional manner. To remedy this situation Magnetic and Inertial forces are used.

Magnetic Confinement [4]

edit

Magnetic Confinement Fusion is considered the main method of confinement from which Fusion reaction is completed. In magnetic confinement method, the heated plasma does not touch the walls of the reactor, but instead it is spun in a helical manner around a torus. The tourus creates a magnetic field that generates the required centripetal force to help keep the extremely hot plasma away from the reactor walls. This method of Nuclear Fusion was achieved at Tokamak Fusion Test Reactor. In 1993 the Tokamak Fusion Reactor was able to achieve critical ignition temperature required for Deuterium-Tritium Fusion. This temperature reached by the Tokamak Reactor was 5.1 x 108 Kelvin. This temperature is 30 times more than the temperature at the core of the Sun.[5]

Inertial Confinement Fusion(ICF)[6]

edit

Inertial Confinement Fusion or ICF uses the inertia created by some type of thermonuclear fuel to reach confinement. A spherical capsule is used to burn thermonuclear fuel which creates a conservation of moment which ultimately releases energy. The fusion reaction is generated by the implosion inside the capsule. Thermonuclear fuel inside the capsule is heated and compressed creating high density material. There are two main methods that are applied when using Inertial Confinement Fusion: Laser Fusion, and Ion-Beam Fusion. Laser fusion forces deuterium-tritium fuel to fuse with each other right before they can move away because of the intense heat and pressure. Ion Beam or particle beam fusion refers to spraying of electrons on deuterium-tritium mixture. It causes a small hydrogen bomb which fuses the deuterium and tritium nuclei.

Lawson Criterion [7]

edit

Nuclear fusion is still in its trial and error stages and the energy yield from the confinement methods stated above does not always provide enough efficiency that justifies the fuel cost. In order to calculate the feasibility and efficiency of nuclear fusion, the Lawson Criterion is applied. The Lawson criterion states the time, temperature, and material required for the nuclear fusion to net a yield. The confinement times vary among isotopes of deuterium.

Deuterium-Tritium Fusion

edit

The time required for the deuterium-tritium fusion can be shown by the equation(n denotes the ion density and s denotes time in seconds:

 

Deuterium-Deuterium Fusion

edit

The time required for the deuterium-deuterium fusion can be shown by the equation(n denotes the ion density and s denotes time in seconds:

 

See Also

edit

References

edit
  1. ^ "The Life-Giving Sun". earthguide.ucsd.edu. Retrieved 2018-04-06.
  2. ^ "Lawson Criteria for Nuclear Fusion". hyperphysics.phy-astr.gsu.edu. Retrieved 2018-04-06.
  3. ^ a b Society, Author: Marion Br�nglinghaus, ENS, European Nuclear. "Fusion". www.euronuclear.org. Retrieved 2018-04-21. {{cite web}}: |first= has generic name (help); replacement character in |first= at position 18 (help)CS1 maint: multiple names: authors list (link)
  4. ^ Ongena, J.; Koch, R.; Wolf, R.; Zohm, H. (2016/05). "Magnetic-confinement fusion". Nature Physics. 12 (5): 398–410. doi:10.1038/nphys3745. ISSN 1745-2481. {{cite journal}}: Check date values in: |date= (help)
  5. ^ "Magnetic Confinement Fusion". hyperphysics.phy-astr.gsu.edu. Retrieved 2018-04-21.
  6. ^ Lindl, John (1995). "Development of the indirect‐drive approach to inertial confinement fusion and the target physics basis for ignition and gain". Physics of Plasmas. 2 (11): 3933–4024. doi:10.1063/1.871025.
  7. ^ http://hyperphysics.phy-astr.gsu.edu/hbase/NucEne/lawson.html. {{cite web}}: Missing or empty |title= (help)