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.
In astronomy class i was told that a grouping of hydrogen must reach 10,000,000K for fusion to occur. Without a sun being a certain size, gravity could never be great enough to generate such high temperatures-brown dwarf.
So, could you artificially accelerate gravity (as in future plans for...
I had a lab about tin's heat of fusion. I need to know tin' specific heat near fusion point. Can anybody advice any useful resourse? I have two books, in which are opposite data. I suppose that liquid tin must have higher heat capacity as solid ("liquid" molecules have more "freedom"). Help me...
Can anyone here tell me how long it will be (roughly) until hydrogen fusion power stations are producing energy at economic rates? it can't be far off can it?
thx
According to this release, bubble fusion (i.e. using ultrasonic waves to induce the rapid collapse of bubbles causing the atoms at the center to fuse), has been convincingly demonstrated in the laboratory.
http://www.rpi.edu/web/News/press_releases/2004/lahey.htm#cool
At least two movies...
Hello I just recently finshed physics honors on a high school level, but my class because of bad weather, and a tight schedule was unable to go over anything having to deal with automic physics. Could anybody direct me to understanding fussion, and the theories that have been brought up about...
I found this. Is it cranks or for real?
http://www.progressiveengineer.com/PEWebBackissues2002/PEWeb%2028%20Jul%2002-2/28editor.htm
http://www.focusfusion.org/
Anyone trying this experiment?
Put a solid cylindrical electrode (anode/cathode) inside a hollow cylindrical or tightly coiled electrode (cathode/ anode) so that there is only a minimal ‘potential space’ between the two electrodes, and immerse them in a suitable electrolyte solution. The...
Hey.
I am doing a lab experiment in school to find the molar enthalpy of fusion of water. Ice and water are mixed in a calorimeter and the temperatures are recorded. Here are my results. Mass of ice cube: 6.61g. Mass of water: 100g. Initial ice temperature: 0 degrees celsius. Initial...
Is helium a better alternative then the current proposed fuels for fusion reactors?
http://www.space.com/scienceastronomy/helium3_000630.html
http://www.asi.org/adb/02/09/he3-intro.html
Is it know why the Earth's core, and indeed the cores of other planets, are "hot" while some are cold? Is it possible that fusion or fission processes are taking place there ?
Dear Folks:
I have posted this Question all over the web, physics forums, science magazines, academics in plasma physics and condensed matter, I have received little response.
Can you be of assistance?
I thought this might interest you. I have been researching Hydrogen-boron...
I am very ignorant on this subject and was just wondering a few things.
What exactly is it (how do they do it), I am having trouble finding information on it.
Why can't it be recreated, or was it really done at all?
Also I was wondering what resources it uses to create the energy.
Thanks
Hi there.
I'm doing an critical essay (~ 5k words) on Fusion Reactors and whether they will be the energy source of the next millenium.
I'm struggling to get to grips with the main scientific problems and proposed solutions of fusion right now. I can find many books on the history of...
Dear Sirs:
I have posted this Question all over the web, physics forums, science magazines, academics in plasma physics and condensed matter, I have received little response.
Can you be of assistance?
I thought this might interest you. I have been researching Hydrogen-boron Fusion...
How far is research really gone? Is there any major breakthrough on its way? Are the first prototypes ready yet?
I'm making a project work on this for school, and I find it hard to find sufficient information in books and likes about this, since clearly, books from the beginning of the last...
fusion in frame...?
hi guys!
i am new in this field, so i hope that "mature" people can show me the way. thanks in advance!
with fusion in frame does it mean that the nucleotide sequences of both DNA fragments i fuse with each other have to act as independent triplet unit? in this way we...
http://www.boston.com/news/globe/health_science/articles/2004/07/27/heating_up_a_cold_theory/
QUOTE:
COLD FUSION
Heating up a cold theory
MIT professor risks career to reenergize discredited
[...]
So over time, cold fusion scientists have become members of a small...
how about cold fusion? I know it's got avid supporters as well as those who say it's total B.S. last I heard, it had something to do with the way Palladium acts in hard water... I'm going to go look some of that up. I want input! anyway, i hear it's possible.
edit: thanks...didn't even notice...
I'm a noob in this lol, but a thought just cross my mind. If in nuclear fusion, we require high temperature to overcome the EM repulsion of nuclei, is it possible to bypass this and simply make use of the nuclear force, or color interaction which holds the nucleus together. Is it possible to...
Over the past year, I've evaluated my own research and observations and matched them up with some statements from a pair of friends. One worked on a nuclear sub, and the other worked on an aircraft carrier. Both worked in the nuclear engine rooms.
As I've been refining the concept of...
Hi, and thanks for looking
I'm doing a heat of fusion lab for school and I'm having trouble trying to find the equations that would solve the following:
Q (heat) released by liquid cooling down
Q (heat) absorbed by melted ice warming up
Q (heat) absorbed by ice while melting
/\ (delta...
I'm somewhat stumped on this question from my son who's in Grade 10 Physics.
Question:
You put 100g of ice into a glass of 2400g of water at 10C.
What is the final temperature of the water?
Hmmm. Sounds simple,
BUT,
I know,
Q= m(delta)H(fus)
where (delta)H(fus)= 333J/g for...
Could anybody give me any suggestions, as to how i could convert 1 mince pie into around about 70 000J of energy, which could be used to power an engine of some sort ?
I ask this, as I am creating a santa statistic :P not very origonal anymore i grant you, however, i was hoping to create a...
why they don't use good ol' accelerator smashing? bring two deutrons to couple of KeV (witch is not a particular problem) and collide them in some vacuum chamber. same charge repulsive force will be couple of magnitudes smaller than force on paticle under acceleration, so where's the problem?
A protostar will begin gravitational collapse only if the total gravitational potential energy exceeds twice the thermal energy. In other words, a gas has to be sufficiently cool and sufficiently dense to collapse. Also, as the protostar collapses about half of the gravitational PE is converted...
[SOLVED] Iron Fusion In Stars
If iron is said to be the last stage of fusion in stars, how is it that heavier elements are found on earth, where there seems to be less likely a chance for such fusion to occur? Where do these elements come from? Moreover, the half-life of a heavy element on...
[SOLVED] "cold fusion realized"
I overheard a discussion the other day and it correlated with something I saw on TV years ago.
It was about "cold fusion realized." It made a lot of sense and now I am fascinated.
What I saw on TV revealed a science experiment where the teacher...
Can we consruct a centrifuge to accelerate ions and coerce them to fuse into heavier elements? It would have to be a sweeping electric field, because any moving parts would disintegrate from the great velocity they'd invariably have to have. Think fusion could be achieved this way?
There is the hydrogen bomb and there is the nuclear weapon that uses plutonium. As far as I know the atomic structure of hydrogen versus plutonium are at the opposite ends of the chemical chart spectrum. Hydrogen having the least atomic weight of all elements and plutonium having a very high...