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Nuclear Fusion
Nuclear fusion is the phenomenon in which multiple atomic nuclei combine to form a single, larger nucleus. Fusion mostly occurs under extreme conditions, due to the large amount of energy it requires. Thus, examples of fusion tend to be exotic; such as stellar nucleosynthesis, the creation of new elements, and thermonuclear weapons.
521 Questions
Nuclear energy is produced by the release of heat from unstable elements such as Uranium. The energy is harnessed by using the energy to heat water. The radioactive water is than pumped through a heat exchanger where the 'dirty water' is used to heat 'clean' water. The clean water can then be used to drive turbines and other forms of engine.
Why does nuclear fusion happen?
Nuclear fusion occurs when two nuclei are placed close enough so that residual binding energy overcomes electromagnetism.
Binding energy holds (among other things) quarks together to form protons and neutrons. Residual binding energy, or nuclear force, holds protons and neutrons together to form nuclei. Both forms of binding energy are strong enough, within the confines of the nucleus, sort of - see the next paragraph, to overcome the repulsive force of electromagnetism for like charged particles.
Both binding energy and electromagnetism are an inverse function of distance. Binding energy has a steeper distance curve, and that complicates things. Within the confines of a single proton or neutron, or within the confines of smaller nuclei (atomic number less than or equal to 82, lead) binding energy wins. At a certain distance, however, electromagnetism wins, causing protons to repel each other.
This magic distance is, primarily, what causes radioactivity, although the weak interaction also has a bearing, but that is not part of the question.
In order for fusion to occur, you have to remove the electron cloud. This is done by adding energy, often substantial amounts of heat, creating an ionized plasma. You also have to force the nuclei together. This is done with substantial amounts of pressure, in order to overcome electromagnetism.
In the stars, this is easy. Gravity does all the work, creating heat and pressure. On Earth, this is hard. We have been successful creating uncontrolled fusion reactions in hydrogen bombs, but we have not been successful creating sustained controlled reactions. We are probably 50 or more years away from being able to do that.
What is the Advantage of maintaining a dikaryotic condition rather than immediate nuclear fusion?
Maintaining a dikaryotic condition allows for genetic recombination and variation to occur through the exchange of genetic material between nuclei, promoting genetic diversity within the organism. This can be advantageous for adaptation and evolution. Immediate nuclear fusion would eliminate this potential for genetic variation.
Is nuclear fusion nonrenewable?
At present it is no kind of energy source and unlikely to be for many years to come. Technically it would be non-renewable, but the raw material is the most common element in the universe so that's not likely to be an insurmountable problem.
Why must an extremely high energy level be reached before a fusion reaction can take place?
Fusion occurs because two nuclei are colliding to create a new nucleus. Because the atoms are positively charged, they naturally repel each other, so high amounts of energy are required to counter-act this force.
What is the potential use of nuclear fusion by humans?
Nuclear fusion has the potential to provide a virtually limitless source of clean and sustainable energy. If successfully developed for power generation, it could help to reduce reliance on fossil fuels, decrease greenhouse gas emissions, and address energy security concerns. Additionally, it could have applications in space exploration and propulsion systems.
How hot must the core of a protostar be to begin nuclear fusion?
The core of a protostar must reach temperatures of at least 10 million degrees Celsius for nuclear fusion to begin. At this temperature, hydrogen atoms can overcome their mutual repulsion and fuse to form helium, releasing energy in the process.
There are different machines being used to fuse atoms. One of the first devices is like the very old vacuum tube. This uses high voltage to compress and fuse atoms.
It finds a lot of use in making medical isotopes. These are products of fission and fusion reactors used in medicine. The vacuum reactor is basically a "fusor". Using a vacuum chamber and high voltage, ions are projected to a central area, usually called the grid. Fusors can be built for only thousands of dollars. Other reactors use very expensive super conducting magnets. Other use high power lasers combined with powerful super conducting magnets to fuse nuclei.
These reactors cost many millions and even billions of dollars. Most all fusion reactors used deuterium and/or tritium fuel. Others use exotic blends. They are most promising because they can produce large amounts of energy with very little of it as neutrons. Neutrons from reactors are very dangerous and require heavy shielding.
Fusion is not commercially feasible at this time due to not reaching break even.
That means they currently use more energy that they generate.
Nuclear fusion to nuclear fission?
Nuclear fusion is the phenomenon in which two lighter nuclei get fused to form heavier nucleus with the production of energy. Best example is SUN and hydrogen bomb.
But nuclear fission of breaking heavier into lighter with the emission of energy. Example uranium-235. So atom bomb
Nuclear fusion has clean energy but fission has hazard energy
What conditions cause nuclear fusion to occur?
Nuclear fusion is caused by a huge amount of energy being absorbed by two atoms that are close to each other and they fuse, or under go fusion to give of that energy. The byproduct of the process is roughly equivalent to the amount of energy that was absorbed by the original two or more atoms.
Energy release of fusion compared to fission?
Fusion releases more energy than fission per unit mass of fuel. Fusion reactions involve combining light atomic nuclei to form heavier ones, releasing large amounts of energy in the process. In contrast, fission reactions involve splitting heavy atomic nuclei, releasing less energy per unit mass.
The amount of mass lost through nuclear fusion is only 7/10 of 1% of the mass of the four hydrogen nuclei. However, it takes a multitude of reactions for the Sun to produce the amount of energy that it does. Each second, the Sun’s lost mass is about 5 million metric tons. When compared to the Sun’s total mass, the amount lost through nuclear fusion is almost insignificant. Therefore, we don't see the Sun decreasing in size.
What happens during nuclear fusion and fission?
In nuclear fusion, two atomic nuclei combine to form a heavier nucleus, releasing a large amount of energy in the process. This is the process that powers the sun and other stars. In nuclear fission, a heavy nucleus splits into two or more lighter nuclei, along with the release of energy and neutrons. This process is used in nuclear power plants to generate electricity.
The neutrons released from Uranium are fast neutrons. In a reactor they are slowed down by a moderator. The moderator could be water, heavy water, graphite, among others. When the neutron is slowed down, it is more likely to create fission.This is what happens with the U-235. The U-238 does not fission, but it does transmute through a series of neutron absorption and beta decay etc. into plutonium which does fission also.
How nuclear fusion is artificially produced on earth?
The most successful attempts so far have been in magnetic torus equipments, where a hot plasma (or ionised gas) is maintained in a circular torus and the fuel is fed into it (isotopes of hydrogen). The best one so far has been the JET (Joint European Torus) but it has only produced fusion for less than 1 second, so there is a long way to go. See link below
How does nuclear fusion create elements inside stars?
Nuclear fusion in stars involves the process of combining lighter elements, such as hydrogen, to form heavier elements, such as helium. As these elements fuse together, they release energy in the form of heat and light. Over time, through a series of fusion reactions, heavier elements are synthesized, up to iron, in the core of stars.
Whats the difference between nuclear fusion and nuclear fission?
Fission is a splitting apart.
Fusion is a putting together.
You get energy by splitting heavy elements AND by fussing light elements.
The mid point is iron, the element with the least amount of available "nuclear" energy ... thus it is the ultimate ash from any nuclear reaction.
The missing material from nuclear fusion changes into an amazing amount of?
The mass deficit in the products of a fusion reaction compared to the mass of the
components before the reaction is completely accounted for by the energy that
leaves the site of the reaction, by means of the relation E = m c2. Most of the
energy is carried away in the form of electromagnetic radiation, and the remainder
is in the kinetic energy of the resultant particles. An individual is free to decide for
himself whether the numbers amaze him.
Where does nuclear fusion happen in the sun?
Existence of Bharat Radiation in solar spectrum reportedly discovered in 2013 led to the discovery of 235-Uranium fission causing Sunlight phenomenon by Padmanabha Rao effect. Based on these latest breakthroughs in solar physics in 2013, for the first time 153 solar lines in the range of Bharat radiation wavelengths from 12.87 to 31 nm could be explained as due to beta, gamma or X-ray emission from fission fragments (radioisotopes)
Which provides more energy per gram of fuel fission or fusion?
Fusion provides more energy per gram of fuel than fission. Fusion reactions release several times more energy compared to fission reactions, making fusion a more efficient and powerful energy source.
The mass of an atom aftre it under goes fission or fusion?
The mass of an atom after undergoing fission or fusion will be less than the original mass because some of the mass is converted into energy according to Einstein's mass-energy equivalence (E=mc^2). In fission, the total mass of the products is less than the original atom due to the release of energy. In fusion, the combined mass of the reactants will be slightly more than the mass of the resulting atom due to the energy input required.
Who was the first person to propose that in nuclear reaction some mass is converted into energy?
Albert Einstein was the first person to propose the mass-energy equivalence principle in his famous equation E=mc^2, where E is energy, m is mass, and c is the speed of light. This laid the foundation for understanding how some mass can be converted into energy in nuclear reactions.
Is nuclear fusion a gas liquid or solid?
Nuclear fusion is a process that occurs at extremely high temperatures and involves the merging of atomic nuclei to release energy. It is not in a specific state of matter like gas, liquid, or solid, as it involves the transformation of matter at the atomic level.
How does nuclear fusion occur in the Sun?
At this time hydrogen to helium burning.
1H + 1H --> 2H + e + ~1 MeV
2H + 2H --> 3H + 1H + ~4 MeV
2H + 3H --> 4He + n + ~17 MeV
and several other side reactions.
When it runs out of hydrogen, the core will begin helium burning. This is much harder to start so it requires much higher pressure and temperature.
3 4He --> 12C
But this will not begin for another 6 billion years.
