What is Fusion reactor: Definition and 51 Discussions

Fusion power is an experimental form of power generation that generates electricity by using nuclear fusion reactions. In a fusion process, two atomic nuclei combine to form a heavier nucleus, while releasing energy. Devices that produce energy in this way are known as fusion reactors.
Fusion occurs in a plasma confined at sufficient temperature and pressure for a sufficient interval. The combination of these constraints is known as the Lawson criterion. Higher values for one element permit lower values in the others.
In stars, the most common fuel is hydrogen. Gravity provides long confinement times and high pressure. The power produced by the fused nuclei sustain the necessary temperature to keep the reaction going. Proposed reactors generally use hydrogen isotopes such as deuterium and tritium (or a mixture of the two), which react more easily than individual protons. This allows them to reach the Lawson criterion without extreme values of the other constraints.
As a source of power, nuclear fusion is expected to have many advantages over fission. These include reduced radioactivity in operation and little high-level nuclear waste, ample fuel supplies, and increased safety. However, the Lawson criterion has not been met in a practical system.
Research into fusion reactors began in the 1940s, but to date, no design has produced more fusion power output than the power input. Most fusion designs produce a stream of energetic neutrons that over time degrade the materials used within the reaction chamber.
Fusion researchers have investigated many confinement concepts. The early emphasis was on the z-pinch, stellarator, and magnetic mirror. Later the tokamak and inertial confinement took the lead. Both designs are under research at large scales, notably the ITER tokamak in France, and the National Ignition Facility (NIF) laser in the United States. Researchers are also studying other designs that may offer cheaper approaches. Among these alternatives, there is increasing interest in magnetized target fusion, inertial electrostatic confinement, and new variations of the stellarator.

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  1. M

    Cylindrical and Symmetrical Nuclear Fusion Reactor

    Hello ! I would like to consult you about this cylindrical nuclear reactor model that I have been thinking of with the idea of reducing the friction of the plasmas with the walls of the Toroidal nuclear fusion reactors that causes the plasma temperature to drop and the nuclear reactions to stop...
  2. Strato Incendus

    Writing: Input Wanted A dangerous space mission that requires a lot of helping hands

    As I've mentioned in a few previous threads, at the midpoint of my sci-fi story on a generation ship, I need a disaster that wipes out about a third of the (male half of) the crew. Several people have suggested things like "a virus that disproportionately affects men", but that didn't quite cut...
  3. A

    Sound waves inside an inert gas fusion reactor

    Hey, its that under educated guy again, I hope the mighty big brains can spare me my feelings. Anyways, I saw this toy that levitated a ball of water using nothing but sound waves. So naturally I tried to apply this to a plasma and fusion. Using a inert gas reactor, or a fusor for that matter or...
  4. Xilus

    Have you heard about the French Fusion Reactor?

    Homework Statement:: French Fusion Reactor Relevant Equations:: F=ma Hey anyone here working on the French Fusion reactor? Heard about it over the radio. ITER just been reading the annual reports from CERN. Kind of a fun read if you haven’t read it yet.
  5. D

    Why does a Polywell Fusion Reactor not generate net power?

    why does a polywell not generate net power? what are the loss mechanisms?
  6. E

    How would electricity be generated from a nuclear fusion reactor?

    How would electricity be generated from a nuclear fusion reactor? How soon do you think that fusion power plants will become a reality?
  7. N

    B A New Way to Make Fusion Reactors More Efficient

    I am quite new to this site. I have been following this technology (fusion) for many years now. It never seems to be any closer to actual deployment. Do you think we are getting closer? What do you think are the major stumbling blocks? The article below I read today. My understanding is that...
  8. KFM

    Help Needed: Magnetic Inertial Hybrid Fusion Reactor

    Can anyone help with this please... Would the following work? Magnetic inertial Confinement Hybrid Fusion Reactor. Peeta Watt lasers are focused on the plasma in the equatorial plane of the multi mega amp plasma pulse within its’ torous geometry between the center post and the merging...
  9. G

    Can a fusion reactor experience a Chernobyl-like situation?

    With any realistic fusion reactor designs, can you imagine a Chernobyl like situation, where they can't stop a critical reaction? Or no, since no unstable isotopes, reaction can be stopped anytime, the worst thing can happen is no power?
  10. lekh2003

    Commercially Feasible Fusion Reactor

    I read an article: https://mashable.com/2017/12/19/nuclear-fusion-company-plans-to-make-carbon-free-energy/ about a company named General Fusion who aim to use plasma balls and pressurized steam pistons to create a 150 million degrees celsius environment for fusion to occur. I also found a...
  11. L

    Engineering Career advice to become a Fusion Engineer

    Hello, I am posting to get some career advice about pursuing a career in fusion physics/engineering. With the construction of ITER in France and all the worldwide research into fusion as an energy source, I am extremely interested in the field and I want to help develop fusion technology. I am...
  12. O

    B Questions regarding stellarators

    I have two questions regarding stellarators: how long can a plasma discharge last in a stellarator? wendelstein 7-x supposedly will achieve 30 minutes in the future with a water-cooled divertor, but can future stellarators achieve longer discharges? or is it going to be like the tokamaks where...
  13. R

    B Fusion Reactor Status: Tri Alpha, Lockheed & More

    Fusion reactor development has long interested me. From what little I know, Tri Alpha is unique as they plan to fuse boron and won't use their reactor as a glorified steam boiler. By fusing boron I believe they avoid producing neutrons. The downside is that requires a higher temperature than...
  14. chandrahas

    Lockheed's compact fusion reactor question

    Magnetic mirrors were thought to be a viable solution for fusion power. But then, we found out that most of the plasma would simply escape. Is this right? So, then we realized that this method might not work. So after many years, Lockheed has come up with a similar model. Lockheeds model is...
  15. rfranceschetti

    Engineering Mech engineering work in nuclear reactors

    Hi all, I would like to know what's the kind of work a mechanical engineer has to perform when being part of the team encharged of building a fusion or a generic nuclear reactor. I find many areas in mechanical engineering attractive, but I believe that fusion reactors have great potential in...
  16. H

    What is the grid loss problem for fusion?

    Hello, I would like to ask for a definition the grid loss problem for fusion in inertial confinement fusion methods using fusors, and what it involves. Also, it was to ask what the main solutions being currently researched are, as it is very difficult to find papers on this field. Many thanks...
  17. A

    What Do You Know About Oleg Lavrentiev?

    I am interested in the story of Oleg Lavrentiev. He was originally a Red Army soldier from a peasant family. He studied physics in his spare time. On one base there was a technical library and he was able to afford to subscribe to a Russian physics journal. Lavrentiev developed ideas for a...
  18. kubaanglin

    B Exploring Nuclear Fusion: IEC Fusion Reactor Construction and Operation

    << Disclaimer by PF -- You may need to get government permits to operate a reactor that produces neutrons and radiation, and this could potentially be a dangerous project >> Hello, I recently finished building a functioning IEC fusion reactor and posted a video of its construction and...
  19. gjonesy

    Is fusion Practical? And is it safe?

    I just read an interesting article on a fusion reactor that was fired up and actually produced hydrogen plasma just like in our own sun. How practical is this technology? And is it safer than fission reactors? What's the waste products if any this will produce? I know its very early faze, but it...
  20. Jeremy Thomson

    Radioactivity of fusion reactor walls vs. fission

    I'm wondering if a fusion reactor would make its walls more radioactive thru neutron activation than a fission reactor, for a given amount of energy. It seems to me that (hydrogen) fusion produces most of its energy as neutrons that are unlikely to absorbed by the sparse near vacuum plasma...
  21. I

    Could a Helium 3 Fusion Reactor Power a Settlement on the Moon?

    I have this project in school for settlement on moon. I have this idea that the large quantities of He 3 on moon could be extracted by heating the regolith at 700 degrees celsius and then could be taken to a reactor in which He 3 could be fused with Deuterium or itself. The heat produced could...
  22. Dr. Octavious

    Designing a Fusion Reactor: Calculating Plasma Currents

    Hello all, This might sound very optimistic for a project but I want to design a thermonuclear fusion reactor. Does anyone know how I can calculate the required plasma current I need in order to start a thermonuclear fusion process? I am using a mixture of Deuterium-Tritium gas. Thanks!
  23. J

    Alternate fuel for TriAlpha Fusion Reactor Design?

    http://news.sciencemag.org/physics/2015/08/secretive-fusion-company-makes-reactor-breakthroughAbove is a link to a news story about the recent Tri Alpha Energy “breakthrough”. It looks to me like a very nice development in increased stability of a proposed reactor design. Tri Alpha emphasizes...
  24. Joshua McAnaney

    My Theoretical Fusion Reactor- Looking For Feedback

    Ok, so before I begin, I'd like to point out that I'm a 16-year-old GCSE student from the UK. Therefore all of my physics knowledge above high school level is self-taught, so I am by no means an expert. Anyway, I plan on building a deuterium reactor this Summer as a personal project, and I've...
  25. T

    Neutron Capture in Hydrogen Fusion Reactor

    A recent issue of Aviation Week described a novel design for a fusion reactor from the Lockheed Skunk Works. It was smaller, simpler and lighter than the extant systems now being built and they're optimistic about it's test run in five years. I wrote a letter to the editor touting this departure...
  26. FuturePhysicist

    Can a Teen Build a Fusion Reactor with a Budget Power Supply?

    Hello, I'm 15 and very interested in physics. I'm building a safe nuclear fusion reactor as a science project. (I know how to safely handle high voltage and radiation) I have a question about the power supply. First off, I know that fusion takes around 40 Kilo-volts and it needs to have a...
  27. .Scott

    How Do You Shield a Compact Fusion Reactor?

    After Lockheed Martins announcement that they were developing a fusion reactor that might fit on the back of a pickup truck, I got into a conversation with someone about how one would shield such a device. So I found some tables that described the cross section of protons at different energy...
  28. A

    Would this fusion reactor work ?

    Coils produce a magnetic field which confines a big plasma ball. The magnetic field is rapidly increased which makes the plasma ball implode. In the compressed state fusion happens. The plasma ball explodes and compresses the surrounding magnetic field. This produces more induction in the...
  29. Crazymechanic

    Fusion reactor helium poisoning

    Hi I have a question , now in fusion reactors like a tokamak design and also in others , if they use say the deuterium tritium mixture as fusion fuel which ends up in some released binding energy , alpha particles, a energetic neutron etc. Now the neutron and alpha particles an d all other stuff...
  30. C

    Length of time to burn fuel in a fusion reactor

    If I have a fusion reactor running at some designated power output (let's say, for instance, 5x10^8 Watts), how can I find how long it takes to burn a fuel source provided I know the composition of the fuel. For this example, let me just say I have half deuterium and half tritium? I'm not...
  31. G

    Will the fusion reactor ITER decrease entropy?

    ITER is the fusion reactor in southern France that hopefully will come online in 2018. According to wiki http://en.wikipedia.org/wiki/ITER The ITER fusion reactor itself has been designed to produce 500 megawatts of output power for 50 megawatts of input power. Does this mean that if...
  32. W

    Lithium Dioxide Cold Fusion Reactor model, is it feasible?

    i'm leaning towards sustainable and renewable energy sources, upon seeing the Ironman film of Jean Favreau, i come to theory that maybe the arc reactor that Stark industries manufactured and designed is quite feasible through cold fusion reaction... is it possible? if it is, please provide any...
  33. K

    Want community feedback on the CrossFire Fusion Reactor

    I wanted to ask the community about something I ran into the other day and I know nothing about physics. I can help you build and hack your network, but stuff like this? Forget it. Other then posting this guy's website, I don't know how to explain it, beyond what he has designed, and his...
  34. B

    Can a Simple Cold Fusion Reactor Save Our Dying Planet?

    Okay. I'm doing a science fair project on we're kiling the Earth and that changing simple everyday things could help save our dying planet. My experiment is going to be cold fusion vs fossil fuels and to perform that experiment I need to build a simple cold fusion reactor. Anybody got any ideas...
  35. J

    Cyclic Fusion Reactor. Passing through each other colliding beams.

    Recently I have placed here the new - viable by my opinion Concept how to produce fusion. By some reasons I have decided not to file the patent application and so for discussing now I am placing here the description of Cyclic Reactor on base of that Concept. Ioseb (Joseph) Chikvashvili
  36. 6

    Has anyone measured the light intensity given off in a fusion reactor?

    I was just wondering if, through all the fusion test done over the years, if anybody has ever mesaured the lux given off dureing a reaction?
  37. C

    Is Rossi's Cold Fusion the Real Deal?

    I've been intrigued to see the Rossi claims being dismissed outright here, without any apparent examination of the evidence. There is pathological science, but there is the opposite - pathological refusal to accept any evidence. Personally, as a scientist and engineer, I prefer to keep an...
  38. N

    Will the new ITER fusion reactor actually work?

    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...
  39. M

    Can Tabletop Cold Fusion Be Achieved with Simple, Safe Materials?

    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...
  40. C

    A New Type of Fusion Reactor or Just a Scam?

    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...
  41. U

    Revolutionizing Energy: The Future of Fusion Reactors Explained

    i was watching this show on the Science Channel and in it they talked about a new type of fusion reactor that is currently being built(construction started like 30 years ago). They said it will produce energy for entire world the same way the sun produces energy (fusing hydrogen). It's suppose...
  42. D

    Compact Fusion Reactor: High Potential Difference Effects

    What would happen if we applied high potential difference to a mixture of deuterium and tritium gases in a superconducting tube?:confused: Would the electric discharge give suffecient energy and conditions for fusion to occur??:rolleyes:
  43. C

    Feasibility of pulsed fusion reactor

    I recently came upon a reference to http://www.focusfusion.org, which led me to discover http://www.prometheus2.net and http://www.electronpowersystems.com. What these companies have in common is they propose to generate power using "clean" proton-boron fusion in a pulsed reactor. By pulsed, I...
  44. M

    Electrostatically confined fusion reactor

    does an electrostatically confined plasma fed tritium produce energetic e3nough neutrons to create tritium if allowed to irradiate deutrium ?
  45. F

    What are projects about nuclear controlled fusion reactor to achieve Q > 1

    What are projects about nuclear controlled fusion reactor to achieve Q > 1, or possibly obtain Q > 1.
  46. F

    Is the Fusor or Plasma Focus a Realistic Option for Controlled Fusion?

    PLEASE INFORM ME ABOUT THE CONTROLLED FUSION REACTOR. Is possible the continuos use the fusor and plasma focus, using fuel : pB11 or D-He3. Please send me information. Best Regards
  47. Pengwuino

    French Fusion Reactor: Fact & Fiction

    French fusion reactor and some other skeptical stuff http://www.sciencedaily.com/upi/index.php?feed=Science&article=UPI-1-20050627-10372700-bc-nukefusion.xml Someone brought this up on a non-scientific site and said it would "provide 2x the worlds energy". Obvious BS so I am wondering if...
  48. O

    Fusion Reactor: A Possible Solution to Generate Thermal Energy?

    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...