Questions tagged [fusion]
The fusion tag is used for questions about nuclear fusion, both the basic process at a physical level and it's use as a potential energy source.
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Speculative: What would happen if towers with supermagnets would be built around an experimental tokamak?
It is a speculative question from an amateur. I am interested in an expert reply carved-out for a non-expert
As I'm avidly observing ITER developments and I'm a great fan of the project (as a child I ...
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18 views
On Nucleus-Nucleus potential for fusion reaction of light nuclei
Its know that in nuclear fusion reactions, the nucleus-nucleus potential cannot be simply given by;
$V(r)=\frac{kZ_pZ_t}{r} for, r>\frac{kZ_pZ_t}{E}$
$V(r)=-U_0 , or, \frac{-U_0}{1+e^{\frac{a-r}{b}...
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Is the 300 second sustained fusion goal set by KSTAR a threshold for net positive energy product of fusion?
KSTAR recently broke a record in fusion technology by maintaining its heat for 20 seconds with a stated goalof reaching 300 seconds.
Why 300? Does 300 get us to the point of net positive energy ...
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40 views
What's wrong with using protium catalytically in a fusion reactor?
P-D fusion results in 3He, then D-3He results in a P+D+D turning into P+4He. Isn't that net energy positive at a relatively low temperature without too many neutrons? Some D+D side products will ...
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1answer
28 views
Radiative Heat Transfer In Nuclear Fusion
Given the extremely high plasma temperatures that are required to sustain a nuclear fusion reaction in a device such as a tokamak reactor, how can such high temperatures be maintained in the presence ...
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3answers
43 views
Another way for production of positive fusion
I am wondering why energy positive fusion cannot be produced in the following manner.
Large tank of hydrogen pressurized to such a high a level it would push the limits of current technology.
...
3
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1answer
69 views
How much of ITER Tokamak's input power could be eliminated in a future commercial fusion reactor? [closed]
The ITER Tokamak is designed to produce 500 MW of thermal output from 330 MW of input power, ignoring electric conversion efficiency.
The heaters require 150 MW (to heat input plasma by 50 MW), the ...
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0answers
12 views
Outside grid for fusor
I, for a while now, wanted to build a little Farnsworth desk fusor. Nothing too powerful, simply a small "desk lamp" if you will. As the fusor needs 2 grids, I was wondering, if it might be ...
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1answer
60 views
What would happen if you tried to use oil as fuel in a fusion reactor? [closed]
At first, this question seemed silly, but there might be some sense to it. OpenAI's GPT algorithm suggested to me that using oil in fusion technology could be a breakthrough. I thought about it for ...
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1answer
44 views
I Need the Z-Machine's Circuit Diagram
Where can I find a copy of the circuit diagram for Sandia Lab's Z-Machine, or indeed for any pulse forming network that outperforms the ordinary Marx bank (if such a thing exists)? Google has let me ...
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41 views
Is the Marx Bank Still the Gold Standard?
Is the Marx bank still the fastest pulse forming network for generating high magnetic fields at large scale, or is there another design that outperforms it?
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Magnetic Lens Size required to ignite a Fusion burn
What are the dimensions and/or mass of the amount of permanent magnets( NdFeB) required to magnetically focus cosmic rays such that instead of 1 muon per square centimeter per minute hitting the ...
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1answer
38 views
Nuclear reactions in stars: tunneling?
Energy production in stars occurs mainly when a nucleus absorbs a proton or fuses with another nucleus. Some examples:
(i) $\rm{p}(\rm{p},\rm{e}^+\nu)\rm{d}~$ and $~\rm{d}(\rm{p},\gamma)^3\rm{He}~$ ...
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2answers
96 views
Reactivity in nuclear fusion
In nuclear fusion, the graph of reactivity is shown as below.
How can we explain that by increasing the temperature after a certain value, the reactivity decreases?
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1answer
36 views
Can fusors be used to turn Uranium 238 into Plutonium 239?
Since a FarnsworthāHirsch fusor is apparently a good fast neutron source that is simple enough to build at home, why can't it be used by rogue states or even terrorists to turn non fissile U-238, ...
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3answers
109 views
What if Jupiter or the Sun was made of rock, like Earth and Mars, rather than gas?
Jupiter is a "gas giant". If it was (significantly) bigger the pressure from gravitation would ignite a fusion process and it would become a star, which is basically what happened to the sun....
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22 views
Do we have energy-positive fusion reactors?
This is something I have been wondering about for a long time. I know modern fusion reactors are far from being commercially viable, and probably just as far from going net positive. Still, has there ...
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2answers
73 views
Why does nuclear fusion not occur with nuclei with a nucleon number higher than 56? Please tell me if I am correct
Please tell me if my assumption is correct.
So nuclear fusion does not occur with nuclei (with a nucleon number higher than 56) because the binding energy of the product nucleus is lower than the ...
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0answers
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What is box shape in ion beam drivers for ICF?
What is the meaning of box shape in the ion beam pulses?
i mean in plasma we say the ion beam irradiating the capsule is box shaped. what does it mean?
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1answer
67 views
What is the difference between ion beam and laser?
What is the difference between laser beams and ion beams, especially in inertial confinement fusion?
In inertial fusion, we use lasers as well as ion beams for driving the reaction. What is the ...
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2answers
79 views
Why is hydrogen-boron called a fusion reaction?
As we know, we usually call fusion such a reaction in which two light nuclei make a heavier one and release energy.
For fission, a heavy nucleus breaks into light ones.
My question is, in proton-boron ...
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2answers
96 views
Are there papers or experiments that point to non-fusion sources of solar neutrinos?
I've read that nuclear fusion is what generates such large quantities of solar neutrinos.
Also saw that it was recently experimentally confirmed that two types/energies of neutrinos are generated in ...
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1answer
45 views
How to calculate the released energy in a fusion reaction knowing the mass of the reactants?
this the reaction formula:$H^2_1 + H^3_1 ->He^4_2 + n^1_0$ (idk how to put the numbers in the left)
and I have the released energy of one reaction $E_r=2,8.10^{-12}J$, How to calculate the released ...
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4answers
128 views
How does the Sun generate its energy?
We all know that the sun generates its energy from nuclear fusion in the core. The electromagnetic radiation produced slowly travels upwards, while constantly being absorbed and re-emitted by the ...
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1answer
55 views
Where is mass defect in nuclear fusion? [duplicate]
The hydrogen is one proton and the helium is two protons and two neutrons. Neutron is a little heavier than the proton. But there is something strange. Where is the mass defection? As a result, the ...
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76 views
Would a highly degenerate cosmic neutrino background affect fusion reactions that proceed via the weak interaction?
This might seem like a really strange question, but here's my reasoning.
A proton-proton fusion reaction proceeds in two steps:
\begin{align*}
p + p + \text{1.25 MeV} &\rightarrow {}^2_2\mathrm{He}...
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1answer
55 views
Nuclear Fusion: What is the cause of transport? (Plasma leakage)
Context: I've been reading about The Hairy Ball Theorem which shows that the ideal shape for magnetic confinement fusion has to be a torus. Given that tokamaks use toroidal magnetic fields, I assumed ...
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2answers
58 views
Could you know in advance specifically when a star will go supernova?
I've been thinking about star trek 2009 and star trek Picard in which they happen to talk about a sun inside a fictional solar system which goes supernova destroying a particularly important planet to ...
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2answers
152 views
Why is there more lead and mercury in the universe than gold?
I am watching a Science Channel program on the collapse of massive stars and it got me wondering... What is the distribution of heavier than iron elements in the universe. (It is my understanding ...
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2answers
44 views
Is there anything quantum mechanical related to Fusion/Fission? ( Instead of special relativity)
Fusion/Fission is always accompanied by the special relativity relationship of $E=mc^2$.
Yet there are atoms that are undergoing change, and that should be in the realm of Quantum Mechanics.
Maybe in ...
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1answer
16 views
Electrostatic Plasma Confinement Fusor
I wish to build a Fusor. Now, in order to build it, a high voltage is required generally achieved through Neon Sign Transformers. If I want to achieve voltages 25 kV or more, how am I supposed to do ...
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1answer
38 views
Minimum amount of Tritium for fusion reaction producing Tritium [closed]
I'm not studying physics. I only worked with basic dynamics and have no idea how to calculate this. It's likely that the answer to the question I'm asking is nonsensical, but, from my point of view, ...
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1answer
19 views
Is heating plasma the only way to initiate fusion?
I was looking at why fusion reactors need to get so hot and the internet said that it needed the momentum to overcome the repulsive forces of two atoms. Is heating the atoms the only way to give it ...
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1answer
31 views
Positron-electron anihilation in the Sun
As 75% of the Sun is Hydrogen and 25% Helium and the latter derives from 4 hydrogen atoms where half of protons that formed neutrons expeled positive charges as positrons that anihilated with nearby ...
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1answer
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Stabelizing Quarks?
I have been recently looking into something called Quark Fusion. The whole thing is a theoretical concept of colliding heavier and lighter Quarks to produce energy.
There is one thing to it tho. It is ...
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2answers
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Is it right interpretation to interpret $E=mc^2$ using potential energy?
I am wondering that it is the right interpretation to interpret $E=mc^2$ with potential energy.
What I mean is this: When I studied nuclear fusion, there was missing mass. The hydrogen's nuclear ...
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2answers
55 views
Does the speed of light determine the energy released in fusion reactions?
The Openstax Astronomy book talks about stars converting mass into energy via fusion reactions:
So far, we seem to have a very attractive prescription for producing the energy emitted by the Sun: ā...
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2answers
75 views
Stellar nucleosynthesis
I would like to learn more about fusion in stars. The question I have is whether there exists a graph showing exactly which elements take part in the reactions.
Here, I managed to find some data ...
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3answers
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How can heavier elements be made from hydrogen atoms?
In a JRE podcast from a few years ago, talking about the idea of a universal constructor, Sam Harris said that we could go to a near-vacuum area of deep space, collect nothing but hydrogen atoms, ...
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1answer
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Could one, with enough electricity to spare, use particle accelerators to mass produce heavy elements
If electrical, and economic limitations are ignored, would it be possible for a civilization to mass produce many millions of tonnes of useful heavy elements using particle accelerators?
Could they ...
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Why isnāt CERN afraid of a fusion reaction in the LHC?
Given that they can reach terrifying energies and temperatures, why isnāt fusion of protons a concern? After all, they start with a plasma and ram protons into each other.
At some point the strong ...
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2answers
79 views
Does a fusion reactor have a cool-down period or can it operate continuously
Can a fusion reactor like ITER maintain it's fusion reaction and generate net output electrical power continuously; so long long as fuel is supplied, or does the reactor need to be shut down ...
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2answers
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Why does the sun have the Fe?
I read the information about 'Abundance in the sun for the elements'. There are a lot of elements in the Sun.
I thought 'how is it possible to exist Fe, Au, and so on in the Sun ?', but I couldn't ...
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1answer
90 views
How much energy is required to fuse two protons? [closed]
What is the kinetic temperature required to fuse two protons in a plasma? How much energy does it release? What are the products of the fusion reaction?
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1answer
46 views
Can gamma rays be blocked or redirected by magnetic or electromagnetic fields?
I've been interested in fusion research for a while now and found that reactions such as the proton-proton cycle produce a lot of gamma rays which require large quantities of water or lead to shield ...
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1answer
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Why do tokamaks and most other fusion reactors use neutral plasmas?
Most experimental fusion reactors use quasi-neutral plasma as the working substance. However, there are numerous advantages to using a non-neutral plasma:
Ease of confinement. Pure proton gases have ...
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1answer
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Where does the negative electrode come from in an HB11 fusion reactor?
I'm an electrical engineer. Throughout my education, I was taught that current always has a return path. This understanding applies to everything.
Batteries use an electrolyte to strip electrons ...
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8answers
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Why doesn't the nuclear fusion in a star make it explode?
I have a rather naive question. In stars such as the Sun, what prevents the whole thing exploding at once? Why is the nuclear fusion happening slowly? I can only assume that something about the fusion ...
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1answer
51 views
In fusion inside stars (sun) or very hot gasses, how do the electrons get bound and what about tritons and D-T vs D-D fusion?
Most texts I've read focus on just the nuclei to begin with, but eventually start talking about Helium (or other) atoms and isotopes. A few aspects aren't clear to me and I'd be grateful for some ...
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Does the proportion of strong nuclear force in a star change during nuclear fusion?
I read that the SNF accounts for 99.9% of the mass of an atom.
So if 4 hydrogen atoms become 1 helium atom during nuclear fusion does that change the proportion of SNF as we have 4 SNFs becoming 1 ...
