Fusion Definition and 834 Threads

Did a brown dwarf ever experience fusion? What is the smallest size star, ie., sustained fusion model? ... how do we determine the mass that will sustain fusion of a star.? What effect does plasma in space have on star's fusion reaction? thank you

Can an accretion disk get dense enough to start fusion? How dense does something have to be in order to start fusion? Does it depend on the material? is there a way of measuring the density of accretion disks?

Is it possible to achieve commercially viable nuclear fusion in purely electrostatic quantum tunneling way?What should be voltage of electrostatic field (no particles bombarment) to overcome Coloumb bareer and make tunneling fusion probable?

Homework Statement For my essay on nuclear fission and fusion, I have to discuss some experimental evidence for nuclear fusion. I also need to find info about scientist that are responsible for developing the theory behind nuclear fusion. I am having trouble find info on these aspect. Any...

Homework Statement A piece of ice at-10 centigrade is heated to -1 C using a certain quantity of energy. Then another 20 times as much energy is necessary to finally obtain water. Using that the specific heat of ice is half of the specific heat of 4.2 kJ/(kg oC) of water, determine the heat...

[FONT="Comic Sans MS"]If iron is the last element to undergo fusion wouldn't it be expected to be at a controlled state. Ie: if the pile wants to go toward Hydrogen, bump up the fusing protons. If it to go beyond the Iron tipping point toward Uranium, adsorb protons. From the Binding Energy...

Hi all, recently I've been reading up on cold fusion(although I don't know a lot about it) and how it would ideally be a good clean energy source to use. This is basically what I understand about fusion and cold fusion: Fusion is a nuclear reaction in which two atoms of the same element bind...

How effective is simulation in fusion research? Many years ago i designed simulators for fission reactors and they were extremely accurate, sometimes approaching 1% accuracy in terms of core behaviour. It seems to me that it should be possible to determine whether ITER can exceed breakeven, for...

Hi A friend of mine is doing an assignment on alternative sources of energy when he came across this site and sent the link to me: http://www.crossfirefusor.com From reading a couple of pages it seems deceptively simple and I'm told that the guy expects to get a net gain of a couple MW of...

Homework Statement (a) An insulated copper container of mass 0.250 kg contains 0.350 kg water. Both the container and the water are initially at 25.0 0C. Then 0.012 kg of ice at 0.0 0C is added to the container. Eventually the container and contents reach thermal equilibrium at 21.7 0C...

The 3He-3He fuel cycle releases protons and alpha particles, plus 12.9 MeV of energy. No matter where I look, I can't find any information about how that 12.9 MeV is distributed over the fusion products, every source just quotes the 12.9 total. Does anyone know how this energy tends to be...

Lots of articles and papers I read talk about the gamma rays produced during fusion reactions. And yet, when I look at equations for fuel cycles, the sum of the energies of the fusion products equals the total energy liberated. Since this implies that all of the energy released in the fusion...

ala the sun? Jupiter's upper atmosphere is composed of about 88–92% hydrogen and 8–12% helium http://en.wikipedia.org/wiki/Jupiter considering many nuclear weapons have a fusion stage would the explosion propogate? what would rain on my parade?

What is the difference between transcriptional and translational fusion? As I understand it, transcriptional fusion places a reporter, like lacZ, downstream of the promoter of your gene of interest (so it does not include your entire gene). Is this the same thing in a translational fusion...

Is there any other form of energy releasing fusion besides hydrogen fusion?

since fusion is not commericially feasible, does hybrid fusion fission reactor change that? http://www.nature.com/nphys/journal/v5/n6/full/nphys1288.html With the increasingly urgent need to find solutions to the impending energy crisis, there is growing interest within the fusion...

Hi, I am a physics undergrad and this term I have to write a 3000 word essay on one of about 10 possible topics. One topic which caught my eye was laser fusion. Whichever topic I choose, I will need to find information from a variety of proper sources (not just trawling google). This is what I...

I can't actually find an explanation of this? I think that bigger plasma volumes suffer less energy/particle loss (and therefore have a greater confinement time), but what is the physical reason for this? Thanks

Why the hell don't we put more money into this? I mean, infinite free clean energy you think would be a drive but it don't seem to be. I mean, the more I think about it the more I wonder why...

Iron: Paramagnetic and Last Fusion Product Iron seems to have many mysterious properties: 1. Strongest ferromagnetic rare Earth element. 2. Last stage of fusion in stars to yield positive energy. 3. Heaviest of the ten most abundant elements. I can imagine how 2 and 3 are likely...

Hi everyone, I'm taking a first year physics course and our upcoming lab is an experiment to determine the Heat of fusion for ice. There are a few questions that I have. Firstly the overall equation is given as Lfm + cm (T2 - 0) = cmw (T1 - T2) + cAmA (T1 - T2) + q Where: m is the...

Molar Heat of Fusion experiment question? Homework Statement In one experiment heat was added to one mole of an unknown solid, at its normal melting point, at a constant rate of 13.1 J/s. If it took 2.33 minutes to melt all of the solid, what was the molor heat of fusion (in kJ/mol) of the...

I have decided to do away with the template; all calculations have been done, I'm just having trouble interpreting the results. An experiment was performed using a calorimeter and warm water. The data collected gave the following values for heat of fusion for ice, and heat of sublimation of dry...

Homework Statement To calculate the height of the potential barrier for a head on collision between two deuterons given that each deuteron is a sphere of radius R Homework Equations Potential of the first deuteron at a distance of 2R from it =V = ke/2R where k = 9 * 10^9 , e= 1.6 *...

I'm trying to find the experimental evidence for quantum tunneling during a fusion reaction. Take the simple D + D -> T + P reaction. I know that the energies required to make this happen are much lower in actual experiment than what would be predicted by Coulomb's model of the electrical...

Homework Statement What quantity of ice at 2 deg Celsius can be melted by 100 J of heat? Homework Equations q = m c (delta) t (mass x specific heat x change in temp) q = m l (mass x heat of fusion) specific heat of ice = 2.09 j/g-K heat of fusion = 6.01 kJ/mol The Attempt...

How is the energy released from nuclear fusion used to generate electricity? From my understanding heat is generated during nuclear fission and this heat is used to heat a fluid and drive a turbine. So how does it work with nuclear fusion?

The following experiment was performed to determine the latent heat of fusion of ice. A 50.0-g aluminum cup was filled with 100 g of warm water. The temperature of the cup and water stabilized at 35C. A 15-g piece of ice at 0C was placed in the water and quickly melted. The final temperature of...

Hello all physicists, Actually, I am trying to solve Chen’s book problems which is titled Intro to Plasma Physics Controlled Fusion, 2ed. I encountered many steps that I would like to discuss with you which still not so clear in my mind. Please take a look into that problems either in your...

Let me first say that the answer to this question is not going to determine my career path; it is just to satisfy my curiosity. I am interested in the research and development nuclear fusion and would like to know how much people in this field make. I have scoured the internet and cannot find...

What are some U.S. & European Universities that have a good graduate program for studying Plasma Physics? I am specifically interested in application to fusion. I know Princeton has the plasma laboratory, but that might be too competitive for me.

I have been searching online for any credible information about fusion or fission occurring and contributing significantly to the Earth internal temperature. Can anyone explain this to me further? So far I have heard several media sources discussing how fusion within the Earth is a...

The radiation flux from the sun at the top of the Earth's atmosphere is 0.139 J cm-2 s-1 at normal incidence. The Earth is 1.50x108 km from the sun. Calculate: (a) the energy production in the sun in MeV/s (b) the rate of hydrogen consumption in g/s (c) how long hydrogen-burning can continue...

Homework Statement If 10 kilogram of ice at zero degrees celsius is added to 20 kilogram of steam at 100 degrees celsius, what is the temperature of the resulting mixture?Homework Equations uhm... perhaps how many solutions are required to arrive at the answer?The Attempt at a Solution I and...

I have 2 questions... I was told that the transmutation of Li-7 to Be-8 by proton collisions at energies below the classical barrier verifies the QM description of the weak interaction cross section. Firstly, I found the leap in logic very confusing - does the weak force have a role in...

Hi all, I've been given an assignment to calculate the temperature increase of the fusion reactor walls in some theoretical event. It is a 30keV plasma energy in which the heat of the entire plamsa is instantaneously dropped on the wall. I can calculate volume of the wall and have the given...

Do you think D+D Nuclear Fusion will be possible within the next 50 or 60 years? Although the Z machine reportedly reached temperatures of over 2,000,000,000 Degrees (F), I doubt we will be able to output enough energy and pressure to make a self-sustaining D+D fusion reaction anytime within the...

Hi everyone, I'm currently taking an astronomy class and I was reading about the fusion reactions in stars and it says that the mass of particles are different in each element. For example the book says helium has a lower mass per nuclear particle than hydrogen. Does this mean that the mass of...

Homework Statement One of the thermonuclear or fusion reactions that takes place inside a star such as our Sun is the production of helium-3 (3He, with two protons and one neutron) and a gamma ray (high-energy photon, denoted by the lowercase Greek letter gamma, ) in a collision between a...

Is the reason why the energy liberating fustion process ends with uranium(more precisely Iron) is that uranium's bindind energy per nucleon begins to decrease and hence will absorb energy rather than emit it, and thus is not self sustaining? Thanks in Advance

What I'm looking to understand is why fission and or fusion result in the release of energy. I understand that: By looking at the Binding Energy per Nucleon Curve, due to the strong force acting at very small length scales and falling off as 1/x^3 and the electro-magnetic repulsion of the...

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 hydrogen to helium...

Hi All, I was wondering about some equations/formulae related to Fusion. How much energy/what temperature does it take to initiate Fusion? And how is this amount of energy affected by the different element/isotopes used, pressure, magnetic attraction and other variables? Thanks in advanced.

I want to take a liquid metal, Aluminum at 700oC and pour it into a steel mold starting at 20oC. For the purpose of the question let’s say that the heat transfer is 100% with no losses to the surroundings. Here are some numbers: Al Mass = 200 g = 0.2 Kg Ti, Al = 700oC Cp = 900 J/Kg-K...

Homework Statement Consider the following fusion reaction 2H+3H →4He + n in which deuterium and tritium fuse together to form a stable isotope of helium plus a neutron. In all of physics, we see experimental confirmation of Conservation of Energy, in which the total amount of energy in a closed...

Hello. I am currently a senior in high school. I am currently taking AP Physics C and will be through calc III/diff eq by the time i graduate. I am interested in going into nuclear engineering but i do not just want to work at some power plant the rest of my life. I am interested in theorhetical...

Calculate heat of fusion.? find the heat of fusion of ice using the ffg. data obtained from an experiment: wt. of brass calorimeter = 50 g specific heat of brass calorimeter = 0.09 cal/g-°C m of ice= 20.45 g at 0°C TF= 20 °C mH2O = 200 g at 30°C

I seem to be having a problem adding a reply to the end of the previous thread so I am starting a new one! Thanks for everyone replying. A couple of points. The first is that nobody seems to have tried two end-on plasmas directed at each other. A dense pair of plasmas fired at each other...

How is fusion initiated with a laser? What are the difficulties that are preventing physicists from using it?

Homework Statement The molar heat fusion and vaporization of benzene are 10.9kJ/mol and 31.0 kJ/mol, respectively. The melting temperature of benzene is 5.5C and it boils at 80.1C. a) calculate the entropy changes for solid to liquid, and liquid to vapor of benzene b) would you expect the...