What is the difference between Nuclear Fission and Fusion?

[DrPosh]

Just curious, I am new to learning about nuclear science and would like to know some differences between Fission and Fusion. Thanks in advance!

-Posh

 

[berkeman]

http://en.wikipedia.org/wiki/Fission

http://en.wikipedia.org/wiki/Fusion

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[Schr0d1ng3r]

Fission is when a heavy nucleus (such as U-235) splits into smaller nuclei. Fusion is when lighter nuclei (such as deuterium and tritium) combine to make a larger nucleus.

 

[wizwom]

Both get their energy from the difference in mass between the fuel and the end products.

Fission breaks apart very high atomic number atoms, which are naturally unstable. The pieces are medium atomic number, but these pieces have many extra neutrons for their number of protons, and are thus very radioactive. The fission reaction is caused by a neutron colliding with the unstable nucleus, so there is no minimum energy, and fission can and does occur at room temperature, in the proper setup.

Fusion combines two very low atomic number atoms, into more stable versions, such as Hydrogen into Helium. The targets of fusion are often "magic", that is they are somewhat like a ball made of smaller balls that Tesselate nicely in 3D. These fusion targets show on a graph of binding energy per nucleon as a tall spike... He4, O16, and so on. Because the point of fusion is getting atomic nuclei with charge to collide, it requires the atoms move fast enough to overcome the natural repulsion of the Coulomb force long enough for the strong force to interact. This means fusion cannot occur under normal circumstances.

The third possibility for nuclear energy is to make combinations of medium atomic number isotopes with a light isotope, a so-called "low energy nuclear reaction." This is about as believable as alchemy, but so was chemistry at one point. There is some talk about using neutrinos to temporarily cause hydrogen to turn into a neutron, for instance. LENR would be cool if it was real, but right now it just makes for good Science Fiction.

 

[alphy]

Nuclear fission and fusion are two different types of nuclear reactions that release large amounts of energy. The main difference between them is the process by which they release energy.

Nuclear fission is the splitting of a heavy nucleus, such as uranium or plutonium, into smaller nuclei. This process releases a large amount of energy in the form of heat and radiation. Fission is the process used in nuclear power plants to generate electricity.

On the other hand, nuclear fusion is the process of combining two light nuclei, such as hydrogen isotopes, to form a heavier nucleus. This process also releases a large amount of energy, but it requires extremely high temperatures and pressures, similar to those found in the core of the sun. Fusion is the process that powers the sun and other stars.

Another difference between fission and fusion is the byproducts they produce. Fission produces radioactive waste that requires careful handling and disposal, while fusion produces helium gas, which is harmless.

In terms of practical applications, fission is currently the only nuclear reaction that has been successfully harnessed for energy production. Fusion, on the other hand, is still in the research and development stage and has not yet been implemented as a viable energy source.

In summary, the main differences between nuclear fission and fusion are the process by which they release energy, the types of reactions they involve, and their current practical applications. I hope this helps to clarify the distinction between the two reactions.