Talk:Thermonuclear weapon

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Above undated message substituted from Template:Dashboard.wikiedu.org assignment by PrimeBOT (talk) 11:17, 17 January 2022 (UTC)

Way too much detail in lede

Reading this article, the lede goes into way too much detail, I think. Paragraphs 3, 4, and 5 of the lede can all go, I think. I'd do it myself except I'm not reading carefully enough to tell if that content is duplicated elsewhere yet, so not sure whether those paragraphs should be moved or just deleted. —Alex (Ashill | talk | contribs) 17:49, 25 March 2021 (UTC)

I agree on both counts: shorten the lede, but leave it to an expert who can make sure no critical content is lost by moving it to later sections. NPguy (talk) 04:28, 26 March 2021 (UTC)

I agree as well (the lede should be much simpler).

Does anyone check to make sure no actively dangerous information is included? One would hate for a terrorist nuke to be attributed to Wikipedia. Patrickwooldridge (talk) 21:06, 22 July 2023 (UTC)

The tricky part is procurement of enriched uranium/plutonium. That's what's stopping terrorists, not the knowledge of how to build it.

There is zero point censoring the wiki page. Friendly Engineer (talk) 19:18, 17 December 2023 (UTC)

If you gave me highly enriched uranium, I could build you a working gun-type device. Otherwise, we would need implosion, and the design of the lenses is far more difficult. More difficult still is the design of a thermonuclear weapon. When the British started, they had absolutely no idea how it was done. The Russians took the route that I would have tried, of layering to produce boosting. The Americans laboured away for years on the classical super before coming up with the Teller-Ulam configuration. Anyone starting now knows that it involves multistaging and X-ray implosion, and that spherical and cylindrical configurations are possible. Hawkeye7 (discuss) 23:22, 20 December 2023 (UTC)

Wikipedia content is (supposedly) all cited to reliable sources; anything attributed to Wikipedia would be better attributed to those prior sources. Also: WP:RECIPE. Also, this article isn't about the kind of crude fission bomb that a terrorist group might be able to assemble; building a thermonuclear weapon that works is extremely complicated, requiring the resources of a state or very large corporation. MrDemeanour (talk) 15:16, 18 December 2023 (UTC)

Agree with Ashill. Paragraphs 3 & 4 and most of 5 in the introduction should go. The intro should include that by using more stages thermonuclear weapons of unlimited power can be made, while there is a limit to the power of fission weapons.--Chetvorno^TALK 01:08, 19 December 2023 (UTC)

I have had a go at rewriting the lead, taking the comment above into account. Here is a proposed new lead:

A thermonuclear weapon, also known as a fusion weapon, hydrogen bomb or H bomb is a second-generation nuclear weapon design that gets the majority of its explosive force from nuclear fusion reactions. Compared with first-generation nuclear weapons, a thermonuclear weapon offers vastly greater destructive power, more compact size, and lower mass. The first full-scale thermonuclear test was carried out by the United States in 1952, and the concept has since been employed by most of the world's nuclear powers.

The design of modern thermonuclear weapons is known in the United States as the Teller–Ulam configuration after its two chief contributors, Edward Teller and Stanislaw Ulam, who developed it in 1951. Similar devices were subsequently developed by the Soviet Union, United Kingdom, France, China and India.

The Teller-Ulam configuration consists of two components: a nuclear fission primary stage fueled by fissile ²³⁵
U
or ²³⁹
Pu
, and a separate nuclear fusion secondary stage containing thermonuclear fuel in the form the heavy hydrogen isotopes deuterium and tritium, and lithium, often in the form of lithium deuteride. X-rays from the fission primary compress the thermonuclear fuel, allowing a nuclear fusion reaction to propagate. Neutrons produced by the secondary stage can be used to initiate fission reactions in a uranium, enriched uranium, or depleted uranium tamper, or to initiate a tertiary fusion stage. In this way, thermonuclear weapons of limitless power can be constructed.

Everything is perfect until someone puts up a proposal, so critique away. Pinging @HowardMorland: Hawkeye7 (discuss) 03:08, 19 December 2023 (UTC)

I think that’s great. I might add back in the sentence at the end of the current introduction about thermonuclear designs being the dominant design for large bombs. (I have not checked whether the excessively-detailed material is elsewhere in the article. If not, it should be; I find it useful to read, just not introduction material.) —Alex (Ashill | talk | contribs) 05:08, 19 December 2023 (UTC)

My understanding is that the Teller-Ulam secondary is also a fission bomb. The primary is ignited by implosion, the secondary by X-ray "pressure" from the primary. The primary consumes only a small percentage of it's fuel. The secondary explosion is enhanced by the presence of a small amount of deuterium and tritium, which generates lots of neutrons; that in turn results in much more complete "combustion" of the fission fuel, so that the secondary produces a much bigger bang than the primary. That is, the bang from the secondary isn't primarily a fusion reaction; it's mainly a fission reaction, made much more efficient by the added neutrons from the fusion of the hydrogen isotopes.

The secondary in large bombs is encased in fissile material such as U238, which serves as both a mirror and a further source of fission fuel. So nearly all the energy produced by a thermonuclear explosion is produced by fission; the fusion reaction serves primarily as a source of neutrons, not of energy.

Is that wrong? MrDemeanour (talk) 10:59, 19 December 2023 (UTC)

Yes. The secondary is a fusion device. It is physically separate from the primary. You are confusing the fusion boosting of the primary (which is part of the primary) with the secondary. The majority of energy in a true thermonuclear device is released by fusion. In the Tsar Bomba, for example, 97% of the yield came from fusion. [1] Not all thermonuclear weapons have a fissionable tamper - see my article on the tamper for details. Hawkeye7 (discuss) 11:23, 19 December 2023 (UTC)

Agree with Hawkeye7 except that the majority of energy is not necessarily produced by fusion in all thermonuclear weapons. In some weapons the fission of the uranium case does provide more energy than the fusion, but that does not make it a "fission bomb". As Hawkeye7 said, the definition of a thermonuclear device is a "staged implosion" device, a fission implosion ignites a fusion implosion outside itself. The Tsar Bomba was a 3 stage device. --Chetvorno^TALK 15:15, 19 December 2023 (UTC)

I also stumbled over the claim that most of the energy released comes from fusion. As I understand it, a large fraction of the energy release comes from fission, including in the tamper of the secondary. Secondaries may also contain fissile material. And tsar bomba, as a one-of-a-kind three-stage weapon, is hardly typical. For thermonuclear weapons with variable yields, the yield varies depending on how much fusion is triggered. At the low end of the yield range, most of the yield is fission. NPguy (talk) 21:50, 20 December 2023 (UTC)

Yes, that is true. However, the primary also performs some fusion in the booster, and may have a tamper too. A large fraction in a thermonuclear device comes from fission, often as much as 50%. Hawkeye7 (discuss) 23:12, 20 December 2023 (UTC)