Introduction
Nuclear bombs are some of the most dangerous inventions that the human mind produced. They were used to end the largest war of all time but almost immediately led to the danger of complete destruction of humanity. Since the 1940s, a wide variety of nuclear weapons have been created that utilized a variety of physical principles and concepts. The necessity to produce innovative and effective types of nuclear weapons during the cold war provided physicists with almost unlimited funding for their research. This is why nuclear weapons have such varied types of construction. This paper will outline the physical properties of nuclear reactions that are present in the majority of conventional nuclear weapons.
Nuclear Fission
Nuclear fission is the process of splitting a heavier atom to form lighter atoms. When the atom is split, it produces a large amount of energy and releases free neutrons and gamma photons. Nuclear bombs often use materials such as uranium-235 and plutonium-239 because they are more easily split. Fission occurs during a strike of neutron and the nucleus of the isotope. When a sufficient amount of neutrons is release, the process becomes self-sustaining because the nuclei located near the strike start to create more fission (Bernstein 31).
For example, the nucleus of uranium-235 is able to split in a multitude of ways. However, the atomic numbers of these ways would always add up to 92 while their atomic masses would add up to 236. The split may produce a variety of other elements such as strontium-95 and xenon-139 (Reed 23). As previously mentioned, the amount of energy released by the separation of the nuclei is extremely large. For uranium-235 it is around 180 million electron volts with the vast majority of it being released as kinetic energy producing a powerful blast. The remaining electron volts are released as gamma energy which often makes up less than 10% of the reaction, but its lasting harmful effect is often the most dangerous element of the reaction. Gamma radiation is able to pass through most materials, and it is able to cause cancer, mutations, and death from radiation in anyone in the fallout radius of the blast. The released radioactive elements may be picked up by the wind through dust and fall on areas far away from the explosion of the bomb, which leads to additional harm to people and the environment.
Nuclear Fusion
The process of nuclear fusion may be considered the opposite of nuclear fission. Instead of splitting a single nucleus into multiple fragments, nuclear fusion is focused on combining two or more atomic nuclei to create a new one. Just as with the fission process, fusion involves a release of a very large amount of energy. The elements involved in fusion are deuterium, also known as hydrogen-2, and tritium, also known as hydrogen-3. The process of fission provides the required pressure and heat to fuse those elements into helium-4 with one neutron and additional energy (Ongena and Ogawa 770).
The process of fusion in a nuclear bomb requires fission to be sustainable. The majority of electron volts is also released as kinetic energy. If the neutrons produced during the fusion process come in contact with plutonium or uranium, it results in a new instance of fission and additional release of 180 million electron volts making a much more powerful nuclear bomb (Grupen and Rodgers 115). The effect of such an explosion would result in an extremely large fireball, blast wave, radiation, fallout and fires that could cover the landmass of almost any country.
Tritium Production
The last common nuclear reaction used in nuclear bombs is the production of Tritium, also known as hydrogen-3. It is primarily used in bombs that utilize fusion-boosted fission and two-stage thermonuclear devices. There are multiple reasons for this. Tritium production occurs when lithium-6 is bombarded with neutrons. Subsequently, the bombarded lithium-6’s nucleus starts to split, which then produces helium-4, tritium and additional 5 million electron volts (Hafemeister 34). The reason for the limited use of this nuclear reaction is the need for a nuclear reactor to provide initial tritium, as well as the relatively low amount of energy released in comparison to standard fission reactions
Conclusion
Most conventional nuclear bombs utilize fission, fusion, and tritium production, or various combinations of the three. Fission is a process of splitting the atom through which a great amount of energy is released. Fusion is the process of combining deuterium and tritium to create helium-4. This process amplifies the effects of fission bombs but is more complex in nature. Finally, tritium production is involved mostly in fusion bombs and is performed by neutron bombardment of lithium-6’s nucleus. Tritium production is an even more complex process and requires the use of a nuclear reactor to produce tritium beforehand. Even the most simple fission bomb is capable of releasing almost 200 million electron volts as kinetic and gamma energy, which makes nuclear bombs the most devastating weapon created by the human race.
Works Cited
Bernstein, Jeremy. One Physicist’s Guide to Nuclear Weapons A Global Perspective. IOP Publishing, 2016. CrossRef, Web.
Grupen, Claus, and Mark Rodgers. Radioactivity and Radiation. Springer International Publishing, 2016. CrossRef, Web.
Hafemeister, David. Physics of Societal Issues. Springer New York, 2014. CrossRef, Web.
Ongena, Jef, and Yuichi Ogawa. “Nuclear Fusion: Status Report and Future Prospects.” Energy Policy, vol. 96, Sept. 2016, pp. 770–78. ScienceDirect, Web.
Reed, B. Cameron. The Manhattan Project: A Very Brief Introduction to the Physics of Nuclear Weapons. Morgan & Claypool Publishers, 2017.