What are Nuclear Fusion and Fission?
Before heading to know about Nuclear Fusion and fission first let's understand the concept of Nuclear Energy.
What is Nuclear Energy?
It is the form of energy formed or obtained due to nuclear transformations (changes) in a radioactive substance. It is common to have a loss in mass of the radioactive substance during this process (Nuclear Transformation) which results in the formation of energy and this energy is called Nuclear energy.
Thus, it can be said that nuclear energy is produced by the conversion of mass into energy with the help of Einstein's mass-energy relation ΔE = Δmc2 , where c = the velocity of light in a vacuum.
What is Nuclear Fusion?
It is the process of combining two light nuclei into a heavy nucleus along with a massive release of energy is known as Nuclear Fusion.
In this process, a small difference in the mass between reactant and product takes place, this difference in mass converts into nuclear energy obeying Einstein's Mass-Energy equivalence relation (ΔE = Δmc2). In a fusion, lighter nuclei like hydrogen, deuterium, tritium, helium, etc are used.
The difficulty arises when two light nuclei are brought together in order to fuse them, due to their same/like nature of charge possessed by them they strongly repel each other which does not let fusion occur. It can only collide if the Kinetic Energy of both the colliding nuclei reaches a certain magnitude that is 0.1 Mev.
The temperature of the colliding nuclei is increased to 106 Kelvin (a measuring unit) in order to increase the energy as of 0.1 MeV. It is also not possible for a Nuclear Fusion to happen without achieving the temperature of this order.
When the required temperature has reached the materials turns into an ionized state with high density, this is called the Plasma state (currently it is known as the fourth state of matter).
The stellar energy ( Energy emitted by the Sun and Stars) is also formed by the fusion principle. The rate of radiating energy of the Sun is about 1026 Joule/second.
There is no doubt that if a body radiates energy at this rate it will be consumed and vanished in no time. But the Sun has a very large mass (about 1030 Kilograms) calculated to be existing for some billions of years more.
Example of Application:
Who didn't heard about the hydrogen bomb? The Hydrogen bomb is one of the best practices and still being used example of the Nuclear Fusion process. It is known to be 1000 times stronger/destructive than that of an Atom bomb even if both of them are used in equal number of mass.
Unlike the normal fusion process, it requires extremely high pressure and temperature for fusion to occur. Once the process starts, it itself maintains the pressure and temperature but some additional support can be given with the help of the atom bomb.
Extreme conditions like high pressure and temperature are achieved by bursting the atom bomb. Thus, it is fair to say that the Hydrogen Bomb is a group of various amount of atom bombs.
What is Nuclear Fission?
It is the process (Nuclear Reaction) in which an extreme amount of energy is released due to the splitting of a heavy nucleus into two smaller and comparable masses. Generally, those elements which have a higher value of neutron-proton ratio are most likely to experience fission reaction/process.
In 1939, two scientists of Germany; Otto Hahn and Fritz Strassman happen to discover this nuclear fission reaction. It came to known that when the Uranium nucleus (92U235 ) is strike with a slow neutron, the nucleus starts splitting into almost two identical individual pieces along with the release of an extreme amount of energy of around 200 MeV per 92U235 and some free neutrons. They named it Nuclear Fission.
On average, 2.5 neutrons are released in Uranium fission. Under favorable conditions, this newly produced neutrons trigger further fission with the atoms of Uranium and continues the process even more. Hence a chain reaction has formed which results in emitting a huge amount of energy.
Types of Fission reaction:-
They can be of two types, namely,
- Explosive/Uncontrolled chain reaction.
- Controlled reaction.
Explosive/Uncontrolled chain reaction:-
A nuclear chain fission reaction in which newly formed neutrons cause to keep the process continue until the material is totally consumed and vanished is called to be an explosive/uncontrolled chain reaction. This type of reaction occurs and finishes very quickly along with the release of a huge amount of energy.
One of the practical examples of this type of reaction is the Atom bomb. The atom bomb was first made by the USA in 1945 during the Second World War and was dropped on two cities of Japan; Hiroshima and Nagasaki. Everything was destroyed by the explosion of the atom bomb and both the city became a radioactive place which very badly affected the people there.
Controlled chain reaction:-
A nuclear chain fission reaction in which the release of energy can be controlled moreover it does not give any explosion and proceeds slowly is called a controlled chain reaction. One of its practical examples is the Nuclear Reactor, the energy released in the nuclear reactor is also used to generate electricity.
In the end, I hope you guys found it helpful, knowledgeable, and have cleared your doubts and problems based on those topics. You may consider asking such questions and any kind of problems and doubts to me in the comment box and I'll be replying back ASAP or by answering with a new post.
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