The atomic bomb or fission bomb is a weapon based on the physics of nuclear energy. It should not be confused with the nuclear or thermonuclear bomb, also known as the fusion bomb; but both are mechanisms that unleash a large amount of energy in the form of a large explosion.
The first atomic bomb, named Trinity, was first detonated on July 16, 1945 in Alamogordo, New Mexico, by the United States, but the most famous nuclear weapons event in history occurred months later, when the Little Boy and Fat Man bombs were detonated over Hiroshima and Nagasaki on August 6 and 9.
How an atomic bomb works? What is the physical process behind this powerful release of energy? To understand it, we must know some notions of nuclear physics.
Probably the most famous equation in history, E = mc2 is precisely the one that defines the processes of nuclear energy. It tells us that energy equals mass times the speed of light squared. What does this translate to? If we weigh any atom and then measure its mass experimentally, we will find that the number obtained is slightly different. This difference in energy is what we call nuclear energy, which holds the subatomic particles together and gives them stability : the protons and neutrons in the nucleus and the electrons that surround it. Einstein’s equation is what defines how mass is related to energy. Although many consider him the unintentional ‘father’ of the atomic bomb, many other scientists contributed to unraveling the secret of nuclear energy, such as Enrico Fermi, who achieved the first nuclear reaction in history.
This nuclear energy is what is released when a fusion or fission event occurs in an atom. Fission, which is what nuclear power plants use to obtain energy, is the disintegration of the atom when it is hit by other neutrons: a kind of ‘break’ into smaller nuclei. For its part, fusion is the process that occurs in stars, like our Sun, and which, as its name suggests, is the opposite process: it fuses atoms, instead of disintegrating them, to obtain energy. At the moment, it has not been possible to obtain a nuclear source effectively through fusion because it requires hundreds of millions of degrees Celsius.
How much energy does an atomic bomb produce?
Does any atom have nuclear energy? Yes, but some atoms are more stable than others. Uranium and plutonium , for example, are very heavy and very unstable atoms, and we need these types of atoms to produce large amounts of energy. Therefore, these are used as nuclear fuel.
A common misconception is that a nuclear power plant can explode in a similar way to how an atomic bomb would . But, as Nuclear Operator points out, a reactor uses 2-5% uranium-235, while an atomic bomb needs 90% enriched uranium.
How do you make an atomic bomb?
To make an atomic bomb you need, for example, a piece of uranium-235 enriched above the critical mass. What does this mean? The most abundant uranium in nature is uranium-238, which is found in an approximate proportion of 90%. Therefore, it must be ‘enriched’ to obtain a sufficient number of uranium-235 atoms. Enrichment is achieved from various isotope separation techniques. Second, critical mass is one that is considered the minimum mass necessary for a chain reaction to occur.
When an atom of a portion of uranium-235 breaks into smaller nuclei, some atoms are thrown; These atoms collide with other nuclei to form the desired chain reaction. This is the basic principle of how an atomic bomb works.
The atomic bomb has a destructive power capable of devastating several kilometers around and spreading levels of radioactivity that are very harmful to DNA. The bomb dropped on Hiroshima was made of uranium-235; that of Nagasaki, of plutonium-239 , which can be isolated through classical chemical procedures.
Starting with the Second World War, several international treaties were signed with the condition not to use or manufacture atomic bombs. However, according to the portal energia-nuclear.net, there are today about 26,000 nuclear weapons in the world.
