Nuclear fusion is a reaction in which two or more atomic nuclei are combined to form one or more different atomic nuclei and subatomic particles (neutrons or protons). The difference in mass between the reactants and products is manifested as either the release or the absorption of energy. This difference in mass arises due to the difference in atomic binding energy between the nuclei before and after the reaction. Fusion is the process that powers active or main sequence stars and other high-magnitude stars, where large amounts of energy are released.
A fusion process that produces nuclei lighter than iron-56 or nickel-62 will generally release energy. These elements have relatively small mass per nucleon and large binding energy per nucleon. Fusion of nuclei lighter than these releases energy (an exothermic process), while fusion of heavier nuclei results in energy retained by the product nucleons, and the resulting reaction is endothermic. The opposite is true for the reverse process, nuclear fission. This means that the lighter elements, such as hydrogen and helium, are in general more fusible; while the heavier elements, such as uranium, thorium and plutonium, are more fissionable. The extreme astrophysical event of a supernova can produce enough energy to fuse nuclei into elements heavier than iron.
In 1920, Arthur Eddington suggested hydrogen-helium fusion could be the primary source of stellar energy. Quantum tunneling was discovered by Friedrich Hund in 1929, and shortly afterwards Robert Atkinson and Fritz Houtermans used the measured masses of light elements to show that large amounts of energy could be released by fusing small nuclei. Building on the early experiments in artificial nuclear transmutation by Patrick Blackett, laboratory fusion of hydrogen isotopes was accomplished by Mark Oliphant in 1932. In the remainder of that decade, the theory of the main cycle of nuclear fusion in stars was worked out by Hans Bethe. Research into fusion for military purposes began in the early 1940s as part of the Manhattan Project. Self-sustaining nuclear fusion was first carried out on 1 November 1952, in the Ivy Mike hydrogen (thermonuclear) bomb test.
Research into developing controlled fusion inside fusion reactors has been ongoing since the 1940s, but the technology is still in its development phase.
I had a question after having read an article in an old Popular Science magazine I found at a children's Hospital.
These two guys apparently are building a nuclear fusion generator that's going to excite hydrogen plasma inside of a magnetic "sphere", and then they're going to use magnetic...
Homework Statement
In a fusion reaction, the nuclei of two atoms join to form a single atom of a different element. In such a reaction, a fraction of the rest energy of the original atoms is converted to kinetic energy of the reaction products. A fusion reaction that occurs in the Sun converts...
I was hoping someone could help clear up a few things about fusion for me.
I've read that fission produces around 1,000,000 times more energy than any chemical recation and that fusion produces 3 to 4 times more energy than fission. I can only find 'estimated' numbers like these, but is there...
Most research on nuclear fusion obviously is done in materials for containing and generating the plasma and this is not the speciality of a nuclear physicist. Is there actually anything for nuclear physicists to do for research other than figuring out a totally new path for achieving fusion?
We did a calorimeter experiment in my school however the teacher warned us that the latent heat of fusion of ice value will be different from the standard value because the ice has water in it and because the ice melts little before actually doing the experiment. However my question is which way...
Hello,I've been wondering if any of you can suggest an internet source that explains nuclear fusion in a not too complicated way.My problem was,that I need it to make a presentation in physics class,but the simple ways it explains it,it says things like ''protons and neutrons are clumped...
Homework Statement
the heat of fusion of water is 6.01 kj/mol. the heat capacity of liquid water is 75.3 j/mol*k. the conversion of 50g of ice at 0 degrees C to liquid water at 22 degrees C requires _____kj of heat.
The Attempt at a Solution
i converted grams of ice to mols and got 2.778...
Q. Our present theory of the sun and the mechanism of
thermonuclear fusion inside it predicts that the following reactions
occur in the sun.
1H + 1H --> 2H + antielectron + neutrino
1H + 1H --> 2H + antielectron + neutrino
electron + antielectron --> photon + photon
electron +...
Homework Statement
Our present theory of the sun and the mechanism of thermonuclear fusion inside it predicts that the following reactions occur in the sun.
1H + 1H --> 2H + antielectron + neutrino
1H + 1H --> 2H + antielectron + neutrino
electron + antielectron --> photon + photon...
Hi everyone,
I am studying the feasibility of using the collision of two beams to obtain nuclear fusion energy. I would like you to recommend me some serious and intersting articles about this. Is there any experiment that does fusion by beam collitions already?
Im open to hear about any...
Hi everyone,
Im currently in the way of learning about fusion to prepare myself for a thesis in this area. The method of colliding beams was what came to my mind the most naturally at first and it has catched my interest ever since. So, this is what i want to ask: Is there any serious...
Homework Statement
A small 50:50 D-T pellet of density p=3g/cm^3 is used for inertial fusion. Estimate minimum energy and power of the laser device required to heat the pellet to T=10^4 eV and to achieve the energy break-even condition
Homework Equations
Lawson criteria: nt>10^20...
http://www.physorg.com/news/2011-01-italian-scientists-cold-fusion-video.html
I know you guys had to have seen this article by now. I am a just a tech guy so most of this is over my head but I am curious what you guys think about it. Is it possible? If you combine Hydrogen with Ni62 or Ni64...
e^- + e^+\rightarrow\overline{\nu}_e + \nu_e + H
Can it possible for this process happen in lab frame? i.e. the positron is accelerated to collide with the electron target.
I am hopeful that the new large ITER tokamak style fusion reactor will be successful.
According to wikipedia:
The ITER fusion reactor itself has been designed to produce 500 MW of output power for 50 MW of input power, or ten times the amount of energy put in. Hereby the machine is...
why is "melting" called "fusion"?
any idea why is "melting" called "fusion"?
molecules during melting are moving farther apart, they are not "fusing" together. It seems counterintuitive to call "melting" "fusion"
I was looking over an old qualifying exam and I came across a problem asking what the maximum height of a mountain on Earth could be. The solution states that the rock at the base of the mountain will melt and flow away when the potential energy of the top layer of the mountain is equal to the...
Hello,
Why is confinement a big problem in fusion and not in fission? Is it simply due to the fact that in fission, we're injecting a neutron that is neutral, and in fusion we're pushing together charged particles? If so, why is that facet not taken care of by reaching the critical ignition...
How close do two room temperature deuterium nuclei need to be to each other to have a one-in-a-quintillion chance of "tunneling" into each other so that the nuclear forces bind them together despite the repulsive effect of the positively-charged protons?
why it is so difficult for scientist to control the fusion reaction
why they not make a lage room with heat resistance walls and make a explosion to start the fusion reaction and add appropiate amount of hydogen by some hole
if small quantity of hydrogen is entered in such room so the...
How much kinetic energy is required for a proton and neutron to fuse(in any given condition)?
I've also heard that a proton-proton fusion is impossible because it needs a lot of kinetic energy, but how much(also comparable to p-n fusion)?
http://www.bbc.co.uk/news/science-environment-12007965"
Can anyone shed any light on this?
Will work on building ITER be delayed or postponed because of this wrangling?
They are talking about absolutely huge amounts of money which is maybe politically unpalatable for many european...
Let's say two nuclei fuse (proton and neutron), it will do effects such as generate energy and so on...my question is,
I want to know all the methods (theoretical or mathematical) which can describe fusion, for e.g calculations, formulas used (schrodinger equation if used)...
I don't need...
I've got one and a half year left of my B.s. studies so I've started thinking about finding a graduate programs. I'm very interested in thermonuclear fusion and I want to do something with that so I've been looking up schools that are doing some research in that field theoretical or experimental...
Looking at these images and video, and thinking about difficulties in holding plasma within EM field, I had an idea:
[PLAIN]http://www.swisseduc.ch/stromboli/etna/etna00/etna0005photo/icons/e71-small.jpg
http://www.swisseduc.ch/stromboli/etna/etna00/etna0005photo-it.html
Video...
Okay, you all are my last hope, as my last brain cell just dripped out of my ear from searching and calculating.
I am needing a scenario for a novel, one where I'd like to get the physics for the detonation portion at least mostly accurate. I wish to employ a pure fusion weapon -- yes, I...
why do scientist insist on confinement as the way of producing power, not something like colliding accelerated particles together?
and is polywell really the best possible method to produce fuion power as the new trend suggests?
This is not a request for help but an opportunity to participate in a Fusion Energy shot online. Please read below.
We are carrying out an education experiment for Fusion Energy. Fusion occurs inside a device called a Tokamak, I'm a PhD student working at Culham Centre for Fusion Energy...
So if we have a supermassive black hole or a regular black hole with gas swirling around it. Can this gas get hot enough to fuse with other gas molecules around it? It seems like there would be enough energy to do this, maybe not. This question seems non-trivial and I think it needs some...
Hi
I assume that two hydrogen atoms fuse together to form one helium atom during nuclear fusion. But what happens when other isotopes of hydrogen fuse together? What happens to two deuterium atoms when they fuse together? Tritium? I'm assuming that they would form an isotope of helium, but...
I've been looking for information on this but can't seem to find any...
So I come to this wonderful place to find answers :)
Everything I read about fusion power talks about D-T fusion being the ideal.
I have two questions:
1. Why isn't a T-T reaction ever discussed? (does it happen...
Hi,
I’m a hobbyist writer with a slight science fiction slant to my stories. Currently my work involves some reference to the much expected nuclear fusion power. I have been doing some research online, but since I’m not a physicist this naturally resulted in a number of questions.
I’m not...
Hey there,
has anyone out there ever attended the summer school run at Culham. I've been told its great by physicists but was wondering how useful it would be for an engineering undergrad with an interest in the field.
The website says its run for undergrads as well as grad students and...
I'm currently studying Freidberg's plasma physics and fusion energy book, I've heard that Fusion between Deutrium and tritium is most suitable for a fusion reactor and how columb barrier plays its role....my question is
what happens when two neutrons fuse together? do they face columb collision?
I'm trying to study concepts of fusion...please help in any means possible...Currently I'm studying freidberg's plasma physics but want to know more...
How high a density would need to be generated to initiate nuclear fusion for a d-d reaction to occur?
I know as we compress, temperature increases, but for a moment consider we can't heat the atoms, we can only compress them.
What kind of density would would need to be reached? (Or is it...
My friend and I are doing table top fusion for our science fair. We can not figure out a sutable replacement for lithum crystals either than magnets. We need independat varibles, because our teacher says that just 2 magnets is not good enough. Also, it has to be cheap and can be handled by 13...
Hello. I know that most fission reactors boils water to move a turbine like this one.
Is the same for a future nuclear fusion power plant, produce heat and boil water?
Some light about this please.
I'm trying to find fusion (let's say of 2 hydrogen nucleus) in particle physics,
I've just started with my self study of Particle physics book, any info in regards to fusion (Any Equation, solution) would be very helpfull..
THANKS.....
I've heard that Sun is not hot enough to sustain thermonuclear fusion at the level we observe. Instead, the solar output relies on quantum tunneling of protons through their natural repulsive barrier. Might this same effect be useful in obtaining controlled thermonuclear fusion? It seems to me...
Homework Statement
In a fusion reaction, the nuclei of two atoms join to form a single atom of a different element. In such a reaction, a fraction of the rest energy of the original atoms is converted to kinetic energy of the reaction products. A fusion reaction that occurs in the Sun converts...
Nuclear fusion and the "end of energy problems" claim
Hi,
Is it me, or does the following claim seem naive?
"If we can achieve fusion here on earth, then the world's energy problem will be solved."
As I understand it, our energy problems are more to do with greed and waste than...
Homework Statement
the lesser amount of binding energy for lighter and heavier nuclei explains fusion and fission. It has been mentioned large amount of energy is released during fusion and fission due to this low binding energy.
i can't understand the concept. binding energy is the the...
Homework Statement
The deuterium nucleus starts out with a kinetic energy of 1.09e-13 joules, and the proton starts out with a kinetic energy of 2.19e-13 joules. The radius of a proton is 0.9e-15 m; assume that if the particles touch, the distance between their centers will be twice that...
Homework Statement
A nuclear reaction being studied for its potential as a source of fusion power is:
21H + 31H -> 42He + 10n
1) calculate energy in MeV released when two atoms fuse according to the reaction above.
2) calculate the energy in joules released per mole of reactants. (ie...
Hey all, i just had a quick question in regards to fusing Boron-11 and a Proton.
If one were to fire protons at a block of Boron-11, about what percent of the protons would actually achieve fusion? Would varying the speed of the protons effect the fusion rate at all? (Other than stopping any...
Homework Statement
Substitute an electron in a neutral hydrogen atom with a muon.
a) calculate the Bohr radius of the ground state for this myonic atom of atom. The answer must be right to at least 2 significant digits.
b) Calculate the fraction of the myon that is located inside the proton...