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Gecko
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topic pretty much explains it. why is it that fusion releases more energy than fission?
Gecko said:topic pretty much explains it. why is it that fusion releases more energy than fission?
ceptimus said:When you fuse ordinary Hydrogen into Helium, 0.7% of the mass is converted to energy. When Uranium undergoes fission only about 0.1% of the mass is converted. So in mass conversion terms, you might say that fusion is about seven times better than fission.
Morbius said:ceptimus,
You can only say that only for a particular reaction - like D-T fusion.
You can't say that "fusion" always releases more than "fission" - it
depends on the reaction.
There's nothing inherently 7X more powerful about fusion -
they BOTH rely on the SAME force - the strong nuclear force.
Dr. Gregory Greenman
Physicist
kapton said:firsly it's known as the weak nuclear force, not the strong. (w+, w- and Z particles)
Fusion has a much greater release of energy, (fission of u235 is about 10 * 8, fusion of D - T is 10 * 8.4 and Lh2/Lox is 10 * 1 per unit of mass/energy)
- (all results are mathematically rounded)
Fusion is much greater per unit of mass, fission releases less energy, this is converse to the binding energy of a nucleus.
The energy release of fission/fusion is on the lengths of (electromagnetic waves - short at a high frequency, photons, kinetically charged atoms and particles, in the form of gamma and xrays).
Fusion releases more energy than fission per unit of mass.
The energy release of fission/fusion is on the lengths of (electromagnetic waves - short at a high frequency, photons, kinetically charged particles, in the form of gamma and xrays).
X-rays and gamma-rays are high energy photons.
X-rays have energies from ~13.6 eV (hydrogen) - up to about 140 keV. The energies are limited by transition energies of K and L shells in atoms, the origin of X-rays.
Gamma rays have very high energy, with the lowest about 80 keV and highest probably around 6-7 MeV or perhaps up to 10 MeV. Gammas originate from nuclear and subatomic particle decay.
Charged particles (ions) are simply that and the kinetic energy is what it is. In plasmas, particle energies are related to the temperature.- Astronuc
.
Why the masses are what they are - that gets complicated.
padawan13 said:haha yeah i know its old, i wasn't really expecting anyone to reply, but thanks.
So you say that mass is not being converted to energy, but a decrease in mass is accompanied by the production of energy. So where exactly does the energy come from? Is it to do with the strong nuclear force, between nucleons?
An explanation of the why the strong nuclear force exists would be great.
When you fuse tritium and deuterium together, the binding energy of the helium product is more than the two fuels.
Where does the energy come from? you say the binding energy, which you also say is the amount of energy needed to break the atom, and sort of counter the atoms attractive force, but i just don't understand how energy can be produced from the binding energy being increased.The "extra" energy is released as heat, kinetic energy, and photons.
padawan13 said:if the energy needed to break the atom (nuclear binding energy) increases, then the energy holding the nucleus together (ill just call it the attractive energy) must also increase.
padawan13 said:please explain it?
It doesn't seem logical that in a fission reaction uranium-235 releases less electron volts per nucleon compared to the fusion reaction T-D, when uranium is around 45 times larger, obviously the size of the nucleus is not a factor. Could it be the binding energy of the atom, uranium has a higher binding energy and therefore releases less, where as the hydrogen isotopes have less binding energy, releasing more energy.
Im basically asking what determines the amount of mass converted to energy, in a fission or fusion reaction?
The key is the difference in binding energy of the reactants and products.padawan13 said:i understand what your saying, why binding energy increases.
Where does the energy come from? you say the binding energy, which you also say is the amount of energy needed to break the atom, and sort of counter the atoms attractive force, but i just don't understand how energy can be produced from the binding energy being increased.
im sorry if I am frustrating you, i just really want to understand this.
kapton said:firsly it's known as the weak nuclear force, not the strong. (w+, w- and Z particles)
Fusion has a much greater release of energy, (fission of u235 is about 10 * 8, fusion of D - T is 10 * 8.4 and Lh2/Lox is 10 * 1 per unit of mass/energy)
- (all results are mathematically rounded)
Fusion is much greater per unit of mass, fission releases less energy, this is converse to the binding energy of a nucleus.
The energy release of fission/fusion is on the lengths of (electromagnetic waves - short at a high frequency, photons, kinetically charged atoms and particles, in the form of gamma and xrays).
Fusion releases more energy than fission per unit of mass.
Drakkith said:There is no explanation as to "why" any of the fundamental forces exist. They simply do.
bbbeard said:[I know this thread is a mix of 6-year-old and month-old messages, but I just spotted it...]
There is a reasonably straightforward explanation for the shape of the nuclear binding energy curve. The Bethe-Weizsäcker mass formula accounts for most of the contributions to atomic mass. However, it does not account for "shell" effects, i.e. the existence of magic numbers that create islands of stability in the chart of the nuclides... See
http://en.wikipedia.org/wiki/Semi-empirical_mass_formula"
BBB
Dmytry said:AFAIK in a typical bomb half of the yield comes from such fission.
Nomadic Mind said:Morbius or Greg thank you for your clarification. I am just a student from college but I am very curious of things, which has led me to read and learn things way ahead of the current classes I am taking. This Message is just to answer: No! It is not too hard to understand that the amount of energy released is directly dependent on the particular reaction applied and not whether is fusion or fission. If I stated this incorrectly please let me know. Many of the posts here were confusing and contradicting and I found yours very useful and I admire your knowledge and passion. I am looking forward to learn more from this forum, again I am just a student so I will not contribute much, instead will absorb as much as I can.
Fusion is considered stronger than fission because it releases significantly more energy per unit mass than fission. This is because fusion involves combining two or more smaller atoms to form a larger one, while fission involves splitting a larger atom into smaller ones. The binding energy per nucleon (the energy that holds the nucleus together) is higher for fusion reactions, resulting in a greater release of energy.
The strength of fusion and fission reactions can be measured by the amount of energy released per reaction. In this regard, fusion reactions are significantly stronger than fission reactions. For example, the fusion of two hydrogen atoms releases about 17.6 MeV (million electron volts) of energy, while the fission of one uranium atom releases about 200 MeV.
The main source of energy in a fusion reaction is the conversion of mass into energy, according to Einstein's famous equation E=mc^2. In fusion, the total mass of the resulting atom is slightly less than the combined mass of the individual atoms before the reaction. This difference in mass is converted into a large amount of energy.
Fusion is considered a cleaner source of energy compared to fission because it does not produce long-lived radioactive waste. In fission reactions, the products of the reaction can remain radioactive for thousands of years, posing a risk to the environment and human health. Fusion reactions, on the other hand, produce only short-lived radioactive waste, which decays to safe levels within a few hundred years.
Yes, there are several challenges in harnessing fusion as a source of energy. One of the main challenges is achieving and maintaining the extremely high temperatures and pressures required for fusion reactions to occur. Another challenge is finding suitable materials that can withstand the intense heat and radiation produced by fusion reactions. Additionally, the development of efficient and cost-effective methods for extracting and utilizing the energy produced by fusion reactions is still a major obstacle.