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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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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1answer
58 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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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
12 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
36 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
17 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
17 views
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
80 views
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
53 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: “...
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2answers
61 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
52 views
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
42 views
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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5answers
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Why isn’t CERN afraid of a fusion reaction in the LHC?
Given that they can reach terrifying energies and temperatures, why isn’t 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
64 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
80 views
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
55 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
33 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
58 views
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
35 views
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
6k views
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
47 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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1answer
31 views
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 ...
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3answers
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Why do stars get bigger and brighter when older?
As stars age, the concentration of Hydrogen in the core decreases which lowers the power output, causing an imbalance between outward radiation pressure and inward gravitational pressure. This causes ...
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0answers
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Theorical efficiency of Chirped Pulse Amplification HB11 fusion reaction
I read that scientists finally reproduced a more efficient fusion with a novel approach.
They accelerate hydrogen inside a pellet with a LASER. A single H atom produces three $\text{He-4}^+$ nuclei.
...
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0answers
50 views
Why is the $\rm CNO$ cycle is much more efficient than the $p$-$p$ cycle?
Why is the $\rm CNO$ cycle is much more efficient than the $p$-$p$ cycle?
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As neutrons are more massive than protons, does the Sun increase its mass while fusioning elements?
Where is the mass coming from when neutrons are produced from protons in the Sun?
If a positron is made, will it possibly annihilate with an nearby electron?
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1answer
23 views
Can a Magnetic Confinement Fusion Tokamak generate An Axial Vertical Field? [closed]
A question from a complete novice:
Perfectly aware that tokamaks confine plasma in a toroid, could they potentially generate an axial vertical electro-magnetic field as a side-effect, or is it ...
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1answer
34 views
Using a Neutron Poison In $D$-$T$ Fusion Reactors to Capture Neutrons
One of the major problems of the $D$-$T$ fusion reaction is that it releases a 14MEV neutron. In large numbers, these neutrons irradiate the chamber walls and wreak havoc on the metallic lattice, ...
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2answers
58 views
Why is the weak force the main limiting factor when it comes to the $p$-$p$ fusion chain, instead of the quantum tunnelling effect?
For the $p$-$p$ fusion reaction chain occurring in the sun, why is it that the main limiting factor placed on the time scale of the initial proton proton fusion into helium due to the fact it is a ...
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1answer
89 views
Why is humanity investing so little on fusion research? [closed]
Optimists expect fusion industry to be a reality in 2080 to 2100. Fusion means clean and unlimited amount of energy, it is the fuel of the universe. Fusion will solve most of our time problems ...
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0answers
15 views
How useful could neutrons as energy directors in fusion (similar to laser-accelerated electrons)
If you directed fast,'hot' neutrons towards a small amount of homogeneously mixed fusion fuel at a point, is fusion likely where the involvement of the neutrons need only be in providing energy and ...
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1answer
60 views
What can be learned from Wendelstein 7-x experiment?
This experiment achieved a stable plasma for 26 seconds.
What do we learn from it in general(why it was done)? and specifically about the possibility of achieving positive energy flow ($Q>1 $) by ...
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'Forces' enacted by hot neutrons in fusion bomb - Pauli exclusion
Are Pauli exclusion 'forces' on a neutron 100% electromagnetic (Lennard-Jones seems more acute relationship compared to electrostatic force)
If so does that neutrons have two forces between them - '...
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1answer
46 views
Can the fusion of deuteron-like nuclei form a new type of periodic table
In late 2019, The Indian Lattice Gauge Theory Initiative, theorized the existence of exotic particles, "which can be formed through the fusion of heavy baryons, similar to the formation of nuclei of ...
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2answers
76 views
How do we know fusion energies?
Crucial to our understanding of stellar evolution is the energies involved in nuclear fusion reactions.
How do we know those energies? How do we know which fusion reactions take place, at which ...
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0answers
59 views
Nuclear Fusion and Quantum Annealing
This is a pie in the sky idea, and a problem finding sort of question that can probably be dismantled easily, but in light of alternative energy needs with climate change, I think it would be ...
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1answer
47 views
Do the MHD equations break down under certain circumstances (and possible connection to fusion experiments)?
The Euler equations produce singularities (in finite time) under certain conditions see here.
When rings of fluid approach each other, in certain simplified scenarios, the Euler equations that ...
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2answers
77 views
Can artificial fusion have the same power density as in Sun's core?
I recently read about solar core, and found that the power density is only 276.5 watts per cubic meter. This seems rather low to me, but on the other hand the Sun is an enormous object, so the total ...
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1answer
70 views
Evolution of red dwarf stars
While low mass stars (initial mass approximately $0.1 M_\odot$ to $0.8 M_\odot$) are quite numerous, their evolution seems to draw relatively little attention. The lower central density and ...
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2answers
111 views
Why do later fusion stages in a star last shorter?
When most of the hydrogen in the core of a massive star has fused to form helium, the next fusion stages (helium, carbon, neon, oxygen, ...) produce less and less energy in a single fusion reaction. ...
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1answer
29 views
What is the force at play in the emission of neutron out of Helium-5
On nuclear fusion, Wikipedia reads (about Tritium-Deuterium fusion):
The (intermediate) result of the fusion is an unstable 5He nucleus, which immediately ejects a neutron with 14.1 MeV. The recoil ...
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2answers
97 views
What is the largest obstacle in practical helium-3 fusion? [closed]
I've been busy looking into clean, sustainable energy solutions (for a project)
I ran into He-He fusion of the isotope He-3, and most of it looks more beneficial than the traditional D-T fusion due ...
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1answer
32 views
Heavy elements creation [duplicate]
Would elements heavier than iron not be extremely rare if only created by supernovae? I believe all elements above hydrogen are created in the star's corona. Hydrogen fusion is not possible in star's ...
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1answer
136 views
Spherical Electromagnet Formed By Six Coils For Plasma Containment and Nuclear Fusion [closed]
Several years ago I have proposed an open source spherical magnetic vessel to contain plasma for nuclear fusion which can be seen by following this link.
A photo of it is seen below.
A question here ...
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1answer
81 views
How does binding energy work?
I do not have a very advanced understanding of binding energy and atomic mass but in my classes, I have learned that the atomic mass is equal to the sum of the number of protons and the number of ...
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1answer
76 views
Hydrogen bomb without fission stage
The majority of existing nuclear warheads are Thermonuclear devices implementing the Teller--Ulam design. It includes a first stage of "traditional" nuclear fission explosive (Uranium and/or Plutonium)...
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1answer
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Can another element “burn” at the same rate as hydrogen does in our sun?
From what I understand our sun doesn't actually "burn", instead a nuclear reaction is taking place, which is the cause of heat, light and a electromagnetic radiation. I believe this is called Hydrogen ...
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2answers
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Why this arrangement of thingys in this light-induced fusion reactor?
Here is a photo from inside a light-induced fusion reactor at the National Ignition Facility, California.
Image source: Wikipedia
I'm not sure what those thingys all around it are but I assume they ...
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1answer
42 views
Why is this reaction considered a nuclear fusion when the daughter isotope has a nucleus with the same mass?
I understand that in nuclear fusion, the colliding particle unites with the parent and fuses into a single nucleus with a higher mass. Sometimes other small particles
(n, p) are given off.
However, ...
