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Reading this article, the lede goes intoway 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)[reply]
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)[reply]
I agree as well (the lede should be much simpler).
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)[reply]
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)[reply]
Agree withAshill. 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.--ChetvornoTALK01:08, 19 December 2023 (UTC)[reply]
I have had a go at rewriting the lead, taking the comment above into account. Here is a proposed new lead:
Athermonuclear weapon, also known as afusion weapon,hydrogen bomb orH bomb is a second-generationnuclear weapon design that gets the majority of its explosive force fromnuclear fusion reactions. Compared with first-generationnuclear weapons, a thermonuclear weapon offers vastly greater destructive power, more compact size, and lower mass. Thefirst 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'snuclear powers.
The design of modern thermonuclear weapons is known in the United States as theTeller–Ulam configuration after its two chief contributors,Edward Teller andStanislaw 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: anuclear fission primary stage fueled byfissile235 U or239 Pu, and a separate nuclear fusion secondary stage containing thermonuclear fuel in the form the heavy hydrogen isotopesdeuterium andtritium, andlithium, often in the form oflithium 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 auranium,enriched uranium, or depleted uraniumtamper, or to initiate a tertiary fusion stage. In this way, thermonuclear weapons of limitless power can be constructed.
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)[reply]
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.
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)[reply]
Agree withHawkeye7 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. --ChetvornoTALK15:15, 19 December 2023 (UTC)[reply]
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)[reply]
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)[reply]
I agree with the above section that the lead should be greatly shortened for new readers. The pageHistory of the Teller-Ulam design should be linked, but the lead should make clear that "Teller-Ulam design" and "thermonuclear weapon" are essentially synonymous.
I also think the lead image should be replaced, ideally with something likew:File:W88 warhead diagram-num.svg. The current image is a poor representation of the topic, as spherical secondaries are used by almost all thermonuclear nuclear weapons, including the majority of non-early designs by the US, and the initially and presumably recent designs of the USSR, UK, and China. Aspherical primaries are also relevant to the modern design, verified to be used by the US and China. Additionally, showing a miniaturized weaponized warhead is relevant to represent the majority of most thermonuclear weapons ever made. The existing image is only applicable to early US designs such as Ivy Mike and presumably Castle Bravo, and does not have any significance in influencing the thermonuclear weapons developed by the next three countries. I think the image description should also delineate nonessential components to a thermonuclear weapon including the primary booster and the secondary sparkplug.Doeze (talk)14:42, 27 June 2025 (UTC)[reply]
Thanks for proposing this before editing. I agree the lead could be shortened, first by moving the historical info to a the Historical section (these sections usually come first in articles, but I don't know whether this convention is ideal for all articles, so I am ok with the location of the History section for now.) and then concisioning the rest.
The only other thought I had was that the overly simple current lead picture is kind of like the frictionless-block-on-a-plane way to start teaching Newtonian mechanics, easier to understand, though far from real-world. We could see if others have an opinion on the image. ---Avatar317(talk)20:31, 3 July 2025 (UTC)[reply]
Thanks! I think some short historical info should be given in the lead, perhaps widening the perspective after as well as before Ivy Mike (which was not weaponizable), but the Greenhouse George mention is maybe unnecessary despite tying in well with the Teller-Ulam chronology. I think the current diagram isn't that much simpler for introduction than the W88 diagram. The four major shapes represent the state of US non-weapons and maybe weapons in the 1950s, while the W88 is largely representative of deployed warheads from many countries in the other seven decades. I also think the unlabelled diagram should be used, so the image caption in the lead can link to the materials and components, and perhaps mention which ones are unnecessary/common variations with note tags.Doeze (talk)13:07, 7 July 2025 (UTC)[reply]
I'm ok with that; I didn't know you intended to explain the components in the caption; you're right, that way they can be linked. Thanks for all your improvements to these articles! ---Avatar317(talk)22:07, 10 July 2025 (UTC)[reply]
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