Talk:Joint European Torus

message: JT-60's wikipedia entry claims that it is "the world's most powerful fusion reactor."  This contradicts the claim in this article that JET "is the largest and most powerful nuclear fusion reactor yet built."  Unless they're both equal in power, they can't both be the most powerful... TerraFrost 04:34, 7 Mar 2005 (UTC)
replies: text: It's so hard to define 'powerful'. Powerful in what way? Maximum heating capability? Alpha-particle self-heating? Total fusion power liberated? I think that unless one is being very specific, it's best to avoid using the term. Dan100 19:55, Mar 7, 2005 (UTC)
The last sentence of the first paragraph appeared confusing to me:
"It was the largest machine in production when the JET design began."
How could JET be the largest machine in production when the design began? :-) I made it clearer by changing to: "At the design stage JET was larger than any such machine then in production."
This omits the previous entry's reference (as shown). Unfortunately the link associated with that now seems out of date. CatNip48 (talk) 19:11, 21 August 2021 (UTC)
thread_title:  Most powerful reactor? 

message: i've just added a lot of theory, pretty much doubling the length of the article. however i am worried about copyright. i based my writings on a HowStuffWorks article, even "stealing" a photo. i hope that, as a educational website, they will have no quarrel with me. can anyone help with the copywrite? i'm out of my depth. mastodon 17:57, 18 January 2006 (UTC)
thread_title:  Theory 

message: I was about to post a comment on the talk page of cold fusion, when I saw that what I think is a fairly basic piece of misinformation is repeated on this article. 
The second paragraph of the cold fusion article currently reads Hot nuclear fusion using deuterium has the potential to yield large amounts of energy, uses an abundant fuel source, and produces only small amounts of manageable waste...
On the same theme, this article (Joint European Torus) currently lists under advantages: Less nuclear waste - Fusion reactors will not produce high-level nuclear wastes, as fission does, so disposal will be less of a problem. In addition, the wastes will not be of weapons-grade nuclear materials as is the case in fission reactors.
That seems wrong on two grounds. Firstly, the development of lining materials to withstand the enormous neutron flux of a sustained D-T reaction at all is a key unsolved problem. The development of such materials that will not become high-level waste is an even bigger challenge, which the proposed materials testing reactor to be constructed in Japan as part of the ITER project will seek to address. So this is really speculation, but it reads as fact.
Secondly, the wastes produced by most fission power stations are anything but weapons-grade, and every new technology that extends the fuel life (more to minimise refuelling stoppages than to reduce fuel usage but it's still a strong trend) makes the spent fuel even less useful for weapons. 
It seems pointless trying to fix the cold fusion article while we have such misleading statements in this one. 
See http://www.iop.org/EJ/abstract/0029-5515/43/7/301/ for one paper that hints at some of the challenges. Comments welcome. Andrewa 16:12, 10 February 2006 (UTC)
replies: text: The majority of the high level waste produced from a fission plant is the by-products of the fission reaction - products such as cobolt-60 and strontium-90. Nasty, nasty stuff. Fusion does not have this source of waste, the by-product of D-T fusion is non-radioactive helium. The advantage of fusion in this regard is correctly stated, a fusion reactor would not produce anywhere near the volume of waste a fission reactor does. CnlPepper 10:12, 5 April 2006 (UTC)
thread_title: Fusion and nuclear waste

message: Eeer, JT-60 achieved a larger power output, didn't they? They had 55 MW of RF and NBI heating, and a Q of 1.25... Danielfong 01:35, 1 March 2006 (UTC)
replies: text: No, JT60U does not run with Tritium. The Q of 1.25 they claim is an estimate of the fusion power that would have been achieved if the D-D fusion plasma in which the experiment was performed were replaced with a D-T plasma. The JET record is a real D-T shot, ie JET really produced power while JT60U did not (D-D fusion produces negligible power in current devices). I've added a referece to the relevant JT60U paper and clarified this the text (btw I forgot to log in before my last edit, the edit listed as 194.81.223.66 is me). CnlPepper 10:12, 5 April 2006 (UTC)
thread_title: World Record

message: Seems to have too much about staffing and construction, and needs more on the engineering design and science programs and results. - Rod57 (talk) 12:59, 7 October 2011 (UTC)
thread_title:  Unbalanced content 

message: One of the interesting design decisions in JET was to not use superconducting magnets (for reasons of cost).
Instead, the magnets are made from thick copper, with internal water pipers for cooling. They are powered via the flywheel generators.
The amount of energy stored in the flywheels (and the amount of temperature rise tolerable for the magnets) is the main reason why JET cannot operate for more than 30 seconds at a time.  — Preceding unsigned comment added by 82.10.237.122 (talk) 23:59, 1 May 2014 (UTC)
replies: text: We should mention that (with a source) - maybe in a new section on critical design decisions.  I estimate it takes about 20 mins to spin up the flywheels (at 8.8 MW each), and presumably less than an hour to re-cool the coils since they can average 22 shots/day. - Rod57 (talk) 19:50, 5 December 2015 (UTC)
thread_title:  flywheels 

message: Can we say, eg in lead, that so far it is the only magnetic confinement fusion device to have used tritium fuel, and [therefore?] is the only one to have generated fusion power (as shown by a neutron flux) ? - Rod57 (talk) 19:42, 5 December 2015 (UTC)
replies: text: No. TFTR was also designed specifically to use D-T fuel with the express goal of reaching breakeven in order to garner political support. It ran on D-T shortly after JET's first attempts. That makes JET one of two machines to do this, with ITER being the next to try. Of course, NIF has also used D-T. Maury Markowitz (talk) 16:18, 15 December 2017 (UTC)
thread_title:  Only one to have used D-T fuel ? - No 

message: The reference says that peak power requirements can be over 1000MW. That's definitely not the same as "up to 1GW", as one is specifically under that figure and the other is specifically over it. The upper bound is greater than 1GW. Some runs may not demand so much power, and not surpass 1GW. I don't see a problem with the phrasing "up to over 1GW" as a way of expressing this, but in any case the current wording is flat out wrong.
201.230.243.47 (talk) 16:52, 9 December 2015 (UTC)
replies: text: Looking great now!
201.230.243.47 (talk) 20:26, 9 December 2015 (UTC)
thread_title:  Power requirements 

message: The only mention of specific experiments and notable results seems to be in the intro. Can we have a larger section with a little more detail ? Maybe chronological ? If there had been lots of detail I was hoping to add something like :
=== He-3 used as radio energy absorber in multi-ion plasma ===
Both MIT's Alcator C-Mod tokamak and the Joint European Torus (JET) have experimented with adding a little He-3 to a H-D plasma to increase the absorption of radio-frequency (RF) energy to heat the H & D ions, a "three-ion" effect.MIT Achieves Breakthrough in Nuclear Fusion Aug 2017
--- Rod57 (talk) 08:39, 18 July 2020 (UTC)
thread_title:  Add notable experiments and results ? 

message: Both MIT's Alcator C-Mod tokamak and the Joint European Torus (JET) have experimented with adding a little He-3 to a H-D plasma to increase the absorption of radio-frequency (RF) energy to heat the H & D ions, a "three-ion" effect.MIT Achieves Breakthrough in Nuclear Fusion Aug 2017
--- Rod57 (talk) 08:39, 18 July 2020 (UTC)
thread_title:  He-3 used as radio energy absorber in multi-ion plasma 

message: Again, as so often in Wikipedia, here a "trap" of an clickable image (the top right image, link https://en.m.wikipedia.org/wiki/File:JointEuropeanTorus_external.jpg), that does NOT appear in an expected bigger size then (would expect full-screen best), but in that near stamp-size format again. Disappointing for users, lost time, annoying and distracting at least me from using Wiki for the next time. Maybe an iPadOS problem (latest version)? 2001:16B8:261D:9800:CD61:C01E:86FA:FDDF (talk) 14:38, 1 July 2022 (UTC)
thread_title:  Image size