Talk:Tokamak

Old stuff

"The tokamak continues to be the most promising device for generating net power from nuclear fusion" Who made that claim and what is it founded upon? There are in fact competing devices such as the polywell (http://en.wikipedia.org/wiki/Polywell)

From the quote: "The hair is analogous to the magnetic field lines needed in a fusion reactor. It turns out that it is impossible to comb hair on a sphere so that no hair sticks up".... How about if I combed the sphere into a very neat afro? every hair would stand on end, so this is not an impossibility is it?

How about if it read:

"The hair is analogous to the magnetic field lines needed in a fusion reactor. It turns out that it is impossible to comb hair on a sphere so that no hairs cross over each other (or are not parallel to each other). A strand of hair that crosses another would be equivalent to an instability in the reactor. However, a hairy doughnut can be so combed by combing along the circumference and with a slight twist, and thus adjustments to the magnetic field can be made to correct the irregularities. This allows the magnetic field to better confine the plasma"

-donville

You don't seem to understand the hairy ball theorem, I've reverted the changes you made as they're incorrect. However I will agree that the section is badly written, and a deeper physical explanation (of what the hairy ball theorem means for confining a plasma) would be good. Suggestions? -TeeEmCee 12:07, 22 September 2006 (UTC)

This is my favorite kind of critical exercise. "You don't seem understand this. I'm not going to bother explaining it in anyway, but trust me, you're wrong." What a waste of time. Eaglizard (talk) 15:27, 31 March 2009 (UTC)

Some indication as to the absolute size of the pictured tokamak would be useful.

Saying it is the "smallest" doesn't mean much without that reference.

The article states that the only way to confine a plasma is with magnetic fields. Surely a plasma can also (albeit momentarily) be confined by its own inertia. Such is the principle of inertial confinement devices (ICD) after all. --- Yes but this isnt an ICD, its a magnetic confinement device.

To say that some thing or some method is the "only way" to do something is always a dangerous and dubious statement - given no mathematical proof of that fact. Even if something is the 99% most likely way, that doesn't make it the "only way". People do need to learn to express themselves with some precision.74.163.36.177 (talk) 14:57, 8 September 2008 (UTC)

Most plasma in the universe is confined by gravity.

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The explanation given in the article for the spelling of tokamak (with a final 'k', to avoid orthographic similarity with 'magic') seems quite dubious. More likely is that the 'g' of 'magnitnaya' is subjected to the typical Russian language devoicing of consonants at the end of a word.

Alodyne 04:25, 4 Feb 2005 (UTC)

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to avoid analogy with the word magic

The Russian word for magic??? I'm confused. - Omegatron 00:03, May 4, 2005 (UTC)

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"Tokamak" comes from Russian "toroidalnaya kamera s magnitnoi katushkoi" (toroidal camera with magnetic coil).

I thought "kamera" was "chamber"? YggdrasilsRoot 28 June 2005 12:53 (UTC)

yes (gritzko)

A key element missing in this explanation is the word "acronym".74.163.36.177 (talk) 15:00, 8 September 2008 (UTC)

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http://nature.web.ru/db/msg.html?mid=1173581&uri=page4.html

Note: most probably, the author of the general idea of tokamak is Sgt. Oleg Aleksandrovich Lavrent'ev (no kidding, his work was sent to I.V.Stalin circa 1949, A.D.Sakharov reviewed that letter). "Nauka i zhizn'" ("Science and life", one of oldest Russian popular science journals) claims that A.D.Sakharov recognized scientific priority of Lavrent'ev, although I don't have the exact quote (by ADS). Dr. Lavrent'ev was working at Kharkov Physics&Technics Institute as of 2001. (gritzko)

http://ufn.ioc.ac.ru/archive/russian/abstracts/abst2145.html "Role of O.A.Lavrent'ev in raising the problem and initiating the research on (manageable?) thermonuclear synthesis in USSR" by B.D.Bondarenko, from USPEKHI FIZICHESKIKH NAUK ("Successes of physics"), a purely academic journal. Resume: although the initial idea by O.A.Lavrent'ev clearly could not be implemented in practice, the proposed original approach (i.e. plasma containment by a field) was further developed by Tamm and Sakharov into a workable solution. Scientific priority of O.A.Lavrent'ev "worth mentioning".

Name

Can anyone from russia confirm which of the two terms is official, or at least which is prevalent ?

• 1) тороидальная камера в магнитных катушках (... in magnetic coils) - currently in article
• 2) тороидальная камера с магнитными катушками (... with magnetic coils) - in Russian Wikipedia article

- JohnyDog 01:51, 5 May 2006 (UTC)

Looks like (2) is prevalent. Gritzko

There is actually third one, according to Merriam-Webster and other similar sources: toroidal'naya kamera s aksial'nym magnitnym polem (toroidal chamber with an axial magnetic field).

To me it seems likely that the acronym has changed over time, as the technology and design has evolved, but I've been unable to verify this. —Preceding unsigned comment added by 129.16.193.62 (talk) 11:24, 6 February 2009 (UTC)

Power generation

What is the plan for extracting the energy generated from fusion in these devices? Will it be used to heat water, or what? A5 16:08, 5 July 2006 (UTC)

Yes, the basic idea is to heat water. See Fusion_power#Subsystems for a bit more detail. - mako 19:47, 5 July 2006 (UTC)

No, there is the strong possibility of using magnetohydrodynamics to generate electricity. —Preceding unsigned comment added by 74.163.36.177 (talk) 15:06, 8 September 2008 (UTC)

Someone ought to put this up since it's in the news... http://upi.com/NewsTrack/view.php?StoryID=20060724-065917-5783r --D3matt

This really should have a section about potential uses and hazards, etc... If I had the info I'd do it. Otherwise, this thing is pretty lame.

Torus In operation

I believe there's also a Torus in operation at the University of Wisconsin-Madison.

Here's some links about it http://sprott.physics.wisc.edu/fusion.htm http://plasma.physics.wisc.edu/mst/html/mst.htm

They do have the Madison Symmetric Torus, but it's a reversed field pinch device not a tokamak. --Gabbec 07:11, 20 October 2006 (UTC)

Well, they also have the Pegasus spherical torus; does this count as a tokamak? NSTX should also be added in that case. --Gabbec 07:19, 20 October 2006 (UTC)

Pegasus's page makes a distinction between tokamaks and spherical torii, so we should probably keep them separate. - mako 02:07, 21 October 2006 (UTC)

If we're going to distinguish between "spherical torus" and "tokamak", we'd better do it in the introduction. There isn't even a Spherical torus page. I think a spherical torus is just a special case of a tokamak, especially at the introductory level. So lets just note that a sperical torus is a kind of tokamak, and include them in this article. --Dashpool 13:03, 17 January 2007 (UTC)

American writers tend to scrupulously differentiate between "tokamak" and "spherical torus" because (I am told) they are considered as separate concepts for funding purposes, although the actual difference is mainly one of emphasis. Here in the UK, "spherical tokamak" is the usage; cf. MAST, the Mega Amp Spherical Tokamak. Dashpool's recommendation is the sensible one. By the by, the plural of "torus" is "tori" - a Japanese torii is something quite different! Dave Taylor 10:26, 10 May 2007 (UTC)

The term "spherical torus" is self-contradictory - sounds typically British. Topologically, a sphere does not have any "holes" through it - but a torus does have one. A torus can be viewed as a sphere with a hole punched through it. Topologically, there exists no method to "smoothly" transform a sphere into a torus, and vice-versa, and so, a sphere and a torus are topologically-distinct in a very important way.

Shape

Should there be a reference to the Hairy ball theorem? --Bkkbrad 16:42, 10 April 2007 (UTC)

Probably. There was a paragraph on it up till this edit last December. Nobody objected to removing it at the time, probably because the theorem and its significance were poorly and maybe incorrectly explained. If you want to return it, be my guest, but please make an effort to make it understandable to the lay reader. --Art Carlson 17:11, 10 April 2007 (UTC)

Photos of the toruses being used in fusion research bring to mind the path of the center of a star orbited by a planet.

The Earth, orbiting the Sun, moves the sun just as do the planets being discovered with spectrographically detected Doppler shift in the stellar spectra. From the Earth, it looks like the center of the Universe moves, relative to the Sun. But the "center of the universe" is equated since antiquity what was always thought to be a firmament, the unmovable. Whether or not this has any secular equivalent is debatable but since antiquity, ideas of the unmoving, immovable something exist in Hindu mythology (Brahman) and other concepts. They use images like trees, for instance, to represent the unmovable.

By trying to create the Universe, are we creating that path? A hot plasma center moving in a circle? Makes a good constructionist goal image...

It would be good to have competent discussion determine this more carefully than I have here. Fusion success might be more quickly attained, though it is certainly already very substantial.

Accounting motion of the Sun caused by Earth

Photos of the Toruses being used in fusion research bring to mind the path of the center of a star orbited by a planet. The sun moves around the barycenter of the solar system, which is the actual center of mass of the solar system, and often this is outside the Sun's surface. Even Earth, orbiting the Sun, moves the sun just as do all other planets, with Jupiter being the main cause of the shift of the barycenter. Motion like this is used in the discovery of extrasolar planets found with Doppler shift in the spectra of many other stars. The center of gravity of the Sun alone moves in a torus around the barycenter.

Is that motion of the sun caused the planets taken into formal account in present day fusion theory and chamber design?

The Earth is the specific object, because it is and contains ourselves and our research and thinking, influencing us subjectively. Earth is the place from which we view the Sun year after year. Other planets and moons go out of phase quickly. But the Sun's motion in a torus is also to be scrutinized.

From the subjective view Earth, which moves -- The center of the Universe, or the center of the Sun?

The 'center of the universe' is equated since antiquity with what was always thought to be a firmament, the unmovable.

Whether or not this has any secular equivalent is debatable but since antiquity, ideas of the unmoving immovable something exist in Hindu mythology (Brahman) and other mythologies which use images like Trees, for instance, to represent the unmovable. It was called by some the Eternally Moving Unmoved Mover, and other grand, inflated phrases.

Of course, relative velocities of the Earth, Moon, and Sun are already well known with high accuracy and the motion of the Milky Way is estimated fairly closely. In other words, are established ancient concepts confusing modern thought?

By trying to create the universe, is any confusion caused by not accounting the motion of the Sun?

A hot fiery gaseous center moving in a circle makes a good constructionist goal image...

It would be good to have competent discussion carefully determine any possible remaining confusion, or a merciful professional describe the solution that was used. Fusion success might be more quickly attained, though it is certainly already very substantial. SyntheticET 03:08, 19 May 2007 (UTC)

Unimportant

But in 'Ohmic Heating' should the 20-30 million degrees Celsius but changed to Kelvin or converted to eV? Celsius is a bit obsolete in the scientific community right? —Preceding unsigned comment added by 86.8.138.110 (talk) 17:28, 2 November 2007 (UTC)

We are talking about a difference of 273 degrees on a scale where the temperature is 25 million plus or minus 5.0 million degrees. The 273 degrees fades into vanishingly-small insignificance and can be ignored. Engineers, chemists, and biologists use Celsius temperatures all the time - but we know when to make the conversion between Celsius and Kelvin whenever it is important - smart! In so many applications, what is important is the difference between two temperatures, and not what the absolute temperature is. For example, in calculating the energy that is released by a certain chemical reaction. 74.163.36.177 (talk) 15:35, 8 September 2008 (UTC)

WikiProject class rating

This article was automatically assessed because at least one WikiProject had rated the article as start, and the rating on other projects was brought up to start class. BetacommandBot 10:04, 10 November 2007 (UTC)

Successes and Failures

I think that a section should be added to this article that explains what the current abilities of a tokamak are. For instance, how long have people been able to contain plasma at fusion-inducing temperatures before it cools? I don't know nearly enough to add that myself. Rhinocerous Ranger (talk) 19:40, 27 March 2008 (UTC)

The answer to that is "not nearly long enough" - and at the bottom line, the "successes" of a tokamak are 0% and the "failures" are 100%. The same applies to all other forms of controlled thermonuclear reaction methods that hav been tried so far. The only manmade, net-energy-producing thermonuclear reaction so far is the hydrogen bomb. 74.163.36.177 (talk) 15:41, 8 September 2008 (UTC)

I don't think its fair to say that tokamaks are failures. To date, AFAIK, there has never been the expectation that they'd be net-energy-producing. They've all been intended to learn more about what was needed to build a working fusion reactor. AFAIK, they've all achieved fusion, just not net-energy production. The same can be said for the Polywell, the Farsnworth-Hirsch, and the Elmore-Tuck-Watson Fusors. EmteeOh (talk) 13:05, 3 August 2011 (EDT) — Preceding unsigned comment added by 208.65.73.39 (talk)

Questions for the article:

Here are some questions that perhaps the article could answer:

• When attempting to read magnetic fusion publications above the ones intended for the general public, one is immediately confronted with numerous mysterious Greek symbols, letters with superscripts, and weird units of measure. I understand what Q is, and why it's important, what magnetic field strength/flux? (in terms of tesla) is, and maybe what the Greek symbol beta stands for in the context of MFE (plasma pressure?), but all of the other general parameters--and there are like 20 or so, I think--could use some explaining in language that's understandable...this would allow people without a background in plasma physics to gain a better understanding of the differing approaches that different MFE experiments have taken, and how research has quantitatively advanced from experiment to experiment. For example, differing experiments seem to be intent on maximizing one statistic or another -- gain, confinement time, temperature, pressure, or the other parameters that I don't understand...what are "good" values for each (high, low, in the middle), how have these values progressed over time since the start of experimentation, how do they effect the design and plasma, what are the parameters that ITER & DEMO are projected to have, and how can one use these parameters and measurements to assess the success of an experiment, and the progress of the science?

The answer to your first comment is that there isn't any other way. You'll just have to learn the scientific language. Also, the idea behind maximizing one "statistic" or another is simply to find out what can be done and what cannot be done. 74.163.36.177 (talk) 16:04, 8 September 2008 (UTC)

• Would a tokamak for power production be "on" all the time, or would it generate power in a series of pulses? Why do so many current tokamaks seem to be more focused on "pulsed" experiments than "steady state" experiments?

The whole idea is that a thermonuclear reactor that produces power in pulses is very likely to be "easier" to do than on that is "on all the time". Otherwise, nobody would bother with the pulsed methods.74.163.36.177 (talk) 16:04, 8 September 2008 (UTC)

• What are the major questions and uncertainties involved in magnetic fusion research that are yet to be answered, that could determine success or failure of magnetic fusion energy? What are the problems remaining to be solved? (I believe a lot have to do with plasma stability and "edge localized modes", along with neutron activation and degradation of operational components, but what are the relative certainties of solving each problem? Or have they been solved (enough)?)

The bottom line is that ALL attempts at making power-porducing thermonuclear reactors are failures so far, and that nobody knows where the crucial breakthroughs might occur. All we can do is to keep on trying. That is the heart of scientific and engineering research into an unknown area.74.163.36.177 (talk) 16:04, 8 September 2008 (UTC)

• Why are most of the MFE concepts (to date) toroidal instead of spherical? On a logical level, I would suppose that a sphere of plasma (or anything) is a lot more compressable than a doughnut, and a lot easier to heat, shoot fuel into, and contain...why isn't this the case?

The whole idea of using a toroid or donut is that you can wind electromagnetic coils around one and attempt to generate a magnetic field of the right shape inside of a toroid. This is impossible for a sphere because there topologically isn't any place to wind the coils. Another imaginable possibility would be to wind the coil around an infinitely-long cylinder (a "solenoid" in the language of physicists), but of course, that is impossible. Nice to think about, though.74.163.36.177 (talk) 16:04, 8 September 2008 (UTC)

• Are there any possibilities to achieve Q > 1 prior to ITER (ex. upgrading JET or JT-60)?

Yes, using a "stellerator", or else a laser machine like the "Shiva", but those haven't worked, either.

• How likely is ITER to succeed, at least from a technical standpoint? Will it achieve a long term burning plasma? Are there any potentially show-stopping technical obstacles?

How likely is ITER to succeed - nobody knows, nobody knows, nobody knows! Otherwise, there wouldn't be much point in building it and trying it out74.163.36.177 (talk) 16:04, 8 September 2008 (UTC)

Iter have some pictures published about their progress on the tokamak at the site. Could be used? http://www.fusionforenergy.europa.eu/mediacorner/imagegallery.aspx?id=33 — Preceding unsigned comment added by 85.200.224.138 (talk) 06:25, 9 October 2015 (UTC)

Maybe these would be good for the article to answer? Katana0182 (talk) 22:02, 8 June 2008 (UTC)

 See no 22 below for PDF info. 

keoka 00:59, 26 January 2015 (UTC)

Current Tokamak news section needed

I had to watch the Science channel to learn that the Tokamak only operates for 30 seconds because the magnets field is not strong enough. They explained the european version will have supermagnets which will keep the plasma away from the walls of the tokamak longer.

Where is this mentioned in this article? —Preceding unsigned comment added by Ericg33 (talk • contribs) 06:50, 6 January 2009 (UTC)

An idea:intermittent Laser Ignition of Deuterium-Tritium within the Torus

Has anyone considered intermittent Laser Ignition of Deuterium-Tritium witin the Torus in order to maintain continuous operation of the plasma field? The DT and the lasers can be ignited as needed to maintain a continuous and stable plasma field. I have this concept as a combination of the US inertial laser system and the Torus approach. Calculations need to be done, but it seems the strong magnetic field of the Torus could also be used for focusing the Laser beams on the DT when needed...ie, when the plasma begins to show signs of fading towards extinguishment. Obviously this must be done with adjusting mirrors and Laser amplification when needed. The magnetic field already required to maintain the Torus seems capable of matching the energy input used at Lawrence-Livermore for DT ignition, superficially at least, but surely someone can run the numbers. Shaping the Laser charge and the US use of reflective Holraums for inertial ignition are issues that must be addressed and modified to suit the Torus.But I see no reason these problems cannot be overcome as the energy output at Lawrence Livermore now exceeds the energy input, thus there should be sufficient energy to mirror-focus and shape the Laser shots "on the run" directly onto the cryogenic DT capsules as they are dropped into the Torus as needed. Essentially what I am asking is.....Can both the Laser Photons and the DT caps be aligned for instant ignition within the Torus as needed to "maintain the flame". Can the energy being used to maintain the Torus be partially redirected to the Laser system as the plasma field fades, then be used to get off a DT shot, and then be redirected back to the Torus maintenance system within nanoseconds? Am I crazy for suggesting this? Feedback from qualified PhD's are appreciated. PS: ITER is using a Berylium compound as its inner surface wall, not ceramics.LaserPhoton (talk) 07:05, 30 December 2011 (UTC)LaserPhoton

See no 22 below for PDF info. - keoka 00:59, 26 January 2015 (UTC)

Wikipedia Talk pages are not the place to suggest new physics experiments. Try some Physics forums ? - Rod57 (talk) 09:33, 18 July 2020 (UTC)

Tokamak

Tokamak —Preceding unsigned comment added by 119.42.155.8 (talk) 17:58, 7 November 2009 (UTC)

Should we archive everything above here ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

If no objections - I'll try to do it one day. - Rod57 (talk) 15:37, 6 December 2015 (UTC)

Alternating current?

The article says that 1987 saw the first demonstration of alternating current in a tokamak. Is it correct that the tokamaks since then all use an AC plasma current? I assume that this AC plasma current is induced by an alternating magnetic field, using the principle of a transformer. How did the tokamaks prior to 1987 generate a DC plasma current? AxelBoldt (talk) 22:09, 27 February 2010 (UTC)

 I'm putting links to PDF's below in no 22, which answer several outstanding questions:
 These answer this question as follows. The most powerful Tokomak so far produces a very
 short pulse which is triggered from the very high current in the windings around the toroid.  

 These pulses produce plasma which in turn induces a high current around the toroid, but 
 not strong enough to initiate fusion so far. 

   http://www.euronuclear.org/info/encyclopedia/t/tokamak.htm
   http://www.euronuclear.org/info/encyclopedia/i/iter.htm
 
 The aim in the next 10 years is to make the plasma pulse strong  enough that it will
 maintain itself and produce huge quantities of energy continuously from a very small
 feed of hydrogen and tritium. 
 

keoka 00:59, 26 January 2015 (UTC)

What is "no 22" ? If you mean a section below it would be easier to find if you give the section title. I'm guessing it's More info on Tokamak. - Rod57 (talk) 09:26, 18 July 2020 (UTC)

History

Experimental research of tokamak systems started in 1956 in Kurchatov Institute, Moscow by a group of Soviet scientists led by Lev Artsimovich.

I have a source that states that the first tokamak was created in 1954: http://www.toodlepip.com/tokamak/discovered-here.htm

--Frozen Serge 23:13, 11 November 2010 (UTC) —Preceding unsigned comment added by Frozen Serge (talk • contribs)

There was an early Tokamak (perhaps 10 feet across with a chamber bore of 6-8 inches?) in mothballs at UCLA when I was there in the 1980's, and another much larger Tokamak that was the twin of one at Princeton that was used for microscopy. The operational Tokamak was powered by a series of Litton microwave ovens that were repurposed to be pumped by an enormous Lincoln Welding transformer. The data collection system consisted of about a dozen Commodore 64 computers that were often destroyed by the intense magnetic field generated during tests. The Tokamak was also electrically insulated with machined teflon approximately 4 inches thick which would melt and flow out the bottom of the device during testing. — Preceding unsigned comment added by 2600:1700:6AE5:2510:0:0:0:46 (talk) 21:46, 30 December 2021 (UTC)

Can you identify it on http://www.tokamak.info/? Maybe Macrotor or the "Continuous Current Tokamak" CCT? It should also be on the list of fusion experiments. Maybe https://www.osti.gov/biblio/1117531/ gives some clues. --Geek3 (talk) 23:58, 30 December 2021 (UTC)

Greetings! Yes, it appears that the tokamaks I saw were Microtor and Macrotor. It is unfortunate that no photographs seem to be extant of the state of Macrotor ca. 1988 when it had the microwave ovens and C64 computers arrayed around it. I scrounged large hunks of scrap Teflon from the project for my own work with graphite resistance furnaces.

It is likely that what was described to me as microscopy apparatus was plasma probe apparatus. This was shared between Princeton and UCLA as their tokamaks went online and offline in scheduled rotation. 2600:1700:6AE5:2510:0:0:0:24 (talk) 19:43, 2 June 2024 (UTC)

Nit picking?

Under "Tokomak Cooling" I cite: "A cryogenic system is used to prevent heat loss from the superconducting magnets." Should this have read instead: "A cryogenic system is used to prevent heat absorption by the superconducting magnets." Or more simply to cool the etc. More knowledgable please answer. Idealist707 (talk) 18:52, 3 January 2012 (UTC)

Major disruption

The phenomenon of major disruptions in Tokamaks is definitely real, but the paragraph discussing not only feels out of place, but is distinctly not NPV. Hpa (talk) 08:39, 18 March 2012 (UTC)

Yes - needs work. Not clear if it is talking about Edge-localized modes or something else. - Rod57 (talk) 15:08, 6 December 2015 (UTC)

confusing

Improper wording leads to ambiguity which leads to misunderstanding of the text. — Preceding unsigned comment added by Jangirke (talk • contribs) 02:56, 30 January 2014 (UTC)

Add section about theories how engergy is supposed to be harvested from the fusion chain reaction

See above. :)

Major disruptions would definitely damage the ITER chamber

From the paper listed as note 7, it states on the first page "The consequences of a disruption in ITER include a divertor power load of between 10 and 100 GWm^-2, which limits the lifetime of the plasma facing components (PFCs)." This comes from another paper which states "The surface-damage potential of interaction of a multi-MA runaway current with localized portions of the at-risk PFC surfaces leads to serious concerns about the high levels of runaway conversion following naturally occurring disruption and intentional ‘fast-shutdown’ actions, intended to ameliorate disruptions." This seems to indicate that the claims are well-founded. — Preceding unsigned comment added by 142.245.59.10 (talk) 04:28, 4 October 2014 (UTC)

We now have Edge-localized mode which describes the instabilities, and how they are being controlled/mitigated. - Rod57 (talk) 09:54, 10 April 2018 (UTC)

No mention of H-mode

How Fritz Wagner "discovered" the H-Mode makes it sound important. "H-mode is what "makes the goals of fusion possible." All tokamaks today are designed to operate in H-Mode and without it, ITER would have needed to be twice as large and, consequently, twice as expensive." Shouldn't it be mentioned in this article ? - Rod57 (talk) 03:23, 23 January 2015 (UTC)

Since it's also possible in stellarators I've started a stub for high-confinement mode (H-mode) - and linked to it. - Rod57 (talk) 15:17, 6 December 2015 (UTC)

Added External link to Observer newspaper

I've added an external link to the Observer/Guardian newspaper which has an informative and illustrated article on a Tokamak being built in France.

keoka 21:48, 25 January 2015 (UTC)

More info on Tokamak

In response to "Questions for the article:" and "Current Tokamak news section needed" sections above, I think we need a header in the main article for updates rather than rewrite the article which hasn't happened in years and I'm not going to take that on. I'll go through the following PDF's I've found which answer quite a few questions like pulsed or continuous, but for a start, here are two PDF links:

 http://www-pub.iaea.org/MTCD/Publications/PDF/csp_008c/pdf/pdp_7.pdf
 http://iopscience.iop.org/0029-5515/43/9/303/pdf/0029-5515_43_9_303.pdf

so if anyone else wants to answer the various queries - have a go.

Here are some more links and info repeated from above:

The most powerful Tokomak so far produces a very short pulse which is triggered from the very high current in the windings around the toroid.

These pulses produce plasma which in turn induces a high current around the toroid, but not strong enough to initiate fusion so far.

 http://www.euronuclear.org/info/encyclopedia/t/tokamak.htm
 http://www.euronuclear.org/info/encyclopedia/i/iter.htm
 

The aim in the next 10 years is to make the plasma pulse strong enough that it will maintain itself and produce huge quantities of energy continuously from a very small feed of hydrogen and tritium.

keoka 00:59, 26 January 2015 (UTC)

Oscillating Tokamak

This article does not include the "oscillating Tokamak" model and it's statistics. In that version, the magnets are generating a vibrating field at very high frequencies, but always controlled - inside the nominal levels. The huge magnets never oscillate, only the field they create. It has no effect if the oscillation is at low frequencies. It causes no heat loss if well designed - it might even increace the temperature. It works better on huge Tokamaks. — Preceding unsigned comment added by 2.84.216.225 (talk) 14:43, 22 June 2015 (UTC)

We need some sources. - Rod57 (talk) 14:43, 6 December 2015 (UTC)

What is different about tokamak

Article isn't clear what a tokamak is and how it differs from a stellarator, and its essential characteristics - eg pulsed operation ? Needs something on how it operates - are the toroidal and poloidal coil currents increased together at a constant rate - then maintained at max level until plasma disperses ? Graphic suggests toroidal coil currents are constant and the poloidal coil currents are pulsed which induces a plasma current which increases the poloidal field ? - Rod57 (talk) 15:53, 6 December 2015 (UTC)

Define advanced tokamak

Maybe based on plasma shape, extending plasma duration with non-inductive current drive ... ? Could start with a section here - later maybe split out ? - Rod57 (talk) 14:28, 16 February 2016 (UTC)

Does it imply using bootstrap currents 2013 for non-inductive (and longer) pulses ? - Rod57 (talk) 10:09, 10 April 2018 (UTC)

Where does fusion actually take place?

I assume the magnetic fields push nuclei into a ring around the center of the ring, forming an inner ring where the fusion actually occurs? The article doesn't mention and a casual web search didn't help. -- Beland (talk) 20:17, 6 June 2016 (UTC)

Full protection for one week

I have no views on whether Bob Guccione should be included (although if so, more tentative wording might be better). If you guys can't sort it out, how about an RfC? Protection is only for a week. Doug Weller talk 08:55, 9 December 2016 (UTC)

Could mention the Greenwald density limit and islands

2015 makes the Greenwald density limit sound significant. What is the density limit ? - Connected with 'island growth' 2015 - Rod57 (talk) 10:03, 10 April 2018 (UTC)

Whether fusion actually takes place

I saw somewhere that there is a hope to make this article FA in the near future. After a quick scan, I was unable to find the answer to what I think is a pretty basic question, and if this article is going for FA, I think that should be addressed.

The question is, at what point in the development of the tokamak were they good enough that it was clear that any fusion was actually taking place? Or, for that matter, has that even happened yet?

To put it another way, at what point did the confidence interval for the Q factor exclude zero?

This is not rhetorical or argumentative. I just wasn't able to determine the answer by reading the article (and I also don't know the answer). It seems to me that the answer must either be known or be the subject of controversy, and in either case there ought to be reliable sources that would allow covering the question in the article. --Trovatore (talk) 00:08, 25 June 2018 (UTC)

@Trovatore: sorry just saw this now. There has been direct evidence for fusion reactions since the US's Theta Pinch machine in 1958. Fusion output has grown steadily since then, and the record is currently held by JET at about 16 MW of output. That it is actual fusion can be demonstrated many ways, including randomly directed neutrons, alphas, x-rays and fusion "ash" in the resulting plasma. Maury Markowitz (talk) 14:37, 4 July 2019 (UTC)

Cool! Thanks for adding a sentence about that to the lead. --Trovatore (talk) 17:00, 4 July 2019 (UTC)

Occurs to me that a great addition would be a graph of the fusion power record by year, if anyone were willing to put in the effort. --Trovatore (talk) 17:13, 4 July 2019 (UTC)

Progress towards break-even and ignition

Is this the article to list the progress towards break-even and ignition? eg. to add record pressures, temperatures, Lawson criterion, or fusion triple product, eg [1] (achieved 2 atm pressure in 2016). - Rod57 (talk) 09:10, 18 July 2020 (UTC)

I found Fusion_power#Records, so added it there, and linked in see-also - Rod57 (talk) 10:13, 18 July 2020 (UTC)

Ronald Reagan sentenced 'Oil crisis is over'

How long before being diagnosed with Dementia was this Reagan pontification? Yeah, the 1973 Oil Crisis rampant prices triggered search for new oil deposits, Middle East still being today the easier and cheaper to extract of it all, but prices made profitable searching and drilling in formerly too expensive sites. Did the crisis reduce overall oil consumption? What were forecasts, actual current figures? In such an scenario, at least for USA, it can be said 'they live on an ocean of oil', supply is no longer an immediate difficulty, even with lines of huge oil transport ships waiting in Sea to have customers, Donald Trump regretted, oil prices are quite stable around $50 a barrel. But the global warming knocks on door, anything reducing oil as source of energy would send oil prices down, increasing oil consumption, thus greenhouse effect gases release. So what? Anyone able to present figures of forecasts in different energy use, energy sources situations? Blessings +

What you say may be correct, but in the context of this article isn't the given statement just sufficient? No matter what the actual situation is, the declaration lead to a historic cut in funding of fusion technologies. --Geek3 (talk) 07:49, 4 June 2021 (UTC)

What about T-15MD ?

"In August 2023, at the Technoprom forum, Alexander Blagov, Vice-President of the National Research Center Kurchatov Institute, announced the first tests for the power start-up of the tokamak" ... "According to Blagov, the first stable thermonuclear plasma was obtained at the T-15MD tokamak, which reached a temperature of more than 100 million degrees Celsius" Is it true ? https://vsluh.net/2530-kurchatovcy-dobilis-proryva-v-termojadernom-sinteze.html?__cf_chl_tk=GRmbrwM9D58WySDZr0DhshCT11OnMwk54CnSzcRHeh8-1692904811-0-gaNycGzNDbs 2A02:AB04:13A:1A00:90:C673:D443:F792 (talk) 14:10, 25 August 2023 (UTC)

It is here: T-15_(reactor)#Upgrade_to_T-15MD. --Geek3 (talk) 13:45, 26 August 2023 (UTC)