# How would fusion based weapons be ? **URL:** \ **Category:** Factual Questions\ **Created:** [December 9, 2005, 7:34pm UTC](https://boards.straightdope.com/t/how-would-fusion-based-weapons-be/334928 "2005-12-09T19:34:23Z")\ **Posts on this page:** 16\ **Page:** 2
**Author:** ![Derleth](https://avatars.discourse-cdn.com/v4/letter/d/b9e5f3/32.png) [@Derleth](https://boards.straightdope.com/u/Derleth)\ **Post date:** [December 10, 2005, 8:59pm UTC](https://boards.straightdope.com/t/how-would-fusion-based-weapons-be/334928/21 "2005-12-10T20:59:28Z")
> [@Rashak Mani](#): > > What about non-bomb fusion weaponry ? No such thing as far as I know. The only way we’ve yet been able to induce fusion in amounts sufficient to be useful in a weapon is by placing small amounts of hydrogen in the middle of a fission bomb and letting the intense fission reaction force the hydrogen atoms to fuse. There isn’t any fusion weapon that doesn’t involve a bomb as its main component, unless you’re talking about focusing sunlight or something. ---
**Author:** ![Citizen\_Bob](https://avatars.discourse-cdn.com/v4/letter/c/f07891/32.png) [@Citizen\_Bob](https://boards.straightdope.com/u/Citizen_Bob)\ **Post date:** [December 12, 2005, 3:39am UTC](https://boards.straightdope.com/t/how-would-fusion-based-weapons-be/334928/22 "2005-12-12T03:39:33Z")
> [@Rashak Mani](#): > > I used to be more in touch with science topics… but age and other hobbies have taken their toll. Plus in fact I had had a bad day and little sleep ! > > What about non-bomb fusion weaponry ? Also non-propulsion… The researchers 'roud here have been having troubles with ‘anomalous transport’ – collecting the energy constructively or in a concentrated way has only been done in short spurts. Magnetic containment equations still need lots of work - will probably be a number of decades before non-explosive/diffusive fusion-anything happens. For general info, try: [http://www.plasmas.org/fusion-mag.htm](http://www.plasmas.org/fusion-mag.htm) Thermonuclear fusion weapons scare the ba-jeezus out of me – I’ve looked up film on more than 30 of the 200-300+ (who knows) US in-atmospheric tests of such devices – each one of them freaks me out, every time. ---
**Author:** ![Malacandra](https://avatars.discourse-cdn.com/v4/letter/m/45deac/32.png) [@Malacandra](https://boards.straightdope.com/u/Malacandra)\ **Post date:** [December 12, 2005, 11:59am UTC](https://boards.straightdope.com/t/how-would-fusion-based-weapons-be/334928/23 "2005-12-12T11:59:39Z")
> [@Polycarp](#): > > A fission weapon works, in short, by the near-instantaneous chain reaction resulting from bringing together a critical mass of a fissionable isotope. Typically this isotope is U-235, Pu-239, or U-233, and the resultant explosion is in the range of the equivalent that would be produced by the explosion of 20,000 tons of TNT. (“Kiloton” and “Megaton” as measurements of the destructiveness of nuclear weapons are based on that parallelism with TNT.) > > **IIRC, the largest conventional bombs used in World War II produced about a one-ton-of-TNT destructiveness.** > > The minimum size of A-bomb in terms of destructiveness is set by what the critical mass for the isotope is. I seem to recall research into an “atomic bullet” (actually an artillery shell), using an isotope of Americium, that could be used tactically, with about the destructivity of a “blockbuster” bomb. There were some five-ton and ten-ton bombs about the place. Modified Lancasters dropped 'em on U-boat pens and railway viaducts, they needed the weight to penetrate the concrete. “Only” about 4 tons of this was explosive, actually Torpex rather than TNT and so with maybe a 5-TNTton yield. ---
**Author:** ![Pushkin](https://avatars.discourse-cdn.com/v4/letter/p/ee59a6/32.png) [@Pushkin](https://boards.straightdope.com/u/Pushkin)\ **Post date:** [December 12, 2005, 2:04pm UTC](https://boards.straightdope.com/t/how-would-fusion-based-weapons-be/334928/24 "2005-12-12T14:04:53Z")
> [@Malacandra](#): > > There were some five-ton and ten-ton bombs about the place. Modified Lancasters dropped 'em on U-boat pens and railway viaducts, they needed the weight to penetrate the concrete. “Only” about 4 tons of this was explosive, actually Torpex rather than TNT and so with maybe a 5-TNTton yield. The [Tallboy](http://en.wikipedia.org/wiki/Tall_Boy) (5,200 lb explosive, 12,000 lb weight in total) and the [Grand Slam](http://en.wikipedia.org/wiki/Grand_Slam_bomb) (9,135 lb explosive, 22,000 lb weight in total.) IIRC from browsing around online, the Grand Slam was the largest conventional bomb dropped, but the US had a larger one built for the purposes of psychological warfare (or maybe they just didn’t get round to using it.) ---
**Author:** ![Revtim](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/revtim/32/1042_2.png) [@Revtim](https://boards.straightdope.com/u/Revtim)\ **Post date:** [December 12, 2005, 2:18pm UTC](https://boards.straightdope.com/t/how-would-fusion-based-weapons-be/334928/25 "2005-12-12T14:18:49Z")
What are fusion bombs like? Scary as fuck. A good book about them is “Dark Sun: The Making of the Hydrogen Bomb” by Richard Rhodes. They were turning islands into underwater craters with these things. IIRC, they had the technology in the 50’s to make a hydrogen bomb so powerful you deploy it by throwing it in your backyard, because it’ll destroy all life on Earth, including your target, no matter where you detonate it. ---
**Author:** ![Polycarp](https://avatars.discourse-cdn.com/v4/letter/p/82dd89/32.png) [@Polycarp](https://boards.straightdope.com/u/Polycarp)\ **Post date:** [December 12, 2005, 2:29pm UTC](https://boards.straightdope.com/t/how-would-fusion-based-weapons-be/334928/26 "2005-12-12T14:29:59Z")
Hydrogen “naturally” fuses into helium, generating massive amounts of energy, when the temperature and pressure are high enough. However, the places where that level of temperature and pressure are found are in the cores of stars. Detonation of a fission bomb produces that degree of temperature and pressure momentarily – long enough to cause a fusion reaction in a H-bomb. Deuterium, tritium, and helium-3 will fuse to produce helium-4 (and other products that break down into it) at relatively lower temperatures than protium, “normal” hydrogen without neutrons. That’s why they’re required in fusion technology, whether bomb or controlled: getting the temperature up to where protium fusion occurs is neither feasible nor necessary for the uses we make of it. [Wikipedia on nuclear fusion](http://en.wikipedia.org/wiki/Nuclear_fusion). ---
**Author:** ![smiling\_bandit](https://avatars.discourse-cdn.com/v4/letter/s/e9a140/32.png) [@smiling\_bandit](https://boards.straightdope.com/u/smiling_bandit)\ **Post date:** [December 12, 2005, 2:50pm UTC](https://boards.straightdope.com/t/how-would-fusion-based-weapons-be/334928/27 "2005-12-12T14:50:53Z")
> [@](#): > > If you have a way of generating more energy than you spend in a controlled manner using fusion, you might have a nobel prize waiting for you. We do not yet have fusion reactors that actually generate useful energy. IIRC they went positive on the energy-meter about 10 years ago, though the gain wasn’t much. > [@](#): > > IIRC, they had the technology in the 50’s to make a hydrogen bomb so powerful you deploy it by throwing it in your backyard, because it’ll destroy all life on Earth, including your target, no matter where you detonate it. Forget “all life” We can conceivable build a bomb big enough to destroy the _entire planet_. Of course, it would be a bomb you could see from orbit. ---
**Author:** ![butler1850](https://avatars.discourse-cdn.com/v4/letter/b/779978/32.png) [@butler1850](https://boards.straightdope.com/u/butler1850)\ **Post date:** [December 12, 2005, 3:09pm UTC](https://boards.straightdope.com/t/how-would-fusion-based-weapons-be/334928/28 "2005-12-12T15:09:26Z")
cite on the “all life” issue? As I remember it, you do start to run up against some physical limits. After a certain “yield” size, you begin to get inefficiencies that don’t really allow you to scale up much more. (The reaction blows away the additional “fuel”, and it’s wasted) ---
**Author:** ![Revtim](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/revtim/32/1042_2.png) [@Revtim](https://boards.straightdope.com/u/Revtim)\ **Post date:** [December 12, 2005, 3:38pm UTC](https://boards.straightdope.com/t/how-would-fusion-based-weapons-be/334928/29 "2005-12-12T15:38:02Z")
> [@butler1850](#): > > cite on the “all life” issue? > > As I remember it, you do start to run up against some physical limits. After a certain “yield” size, you begin to get inefficiencies that don’t really allow you to scale up much more. (The reaction blows away the additional “fuel”, and it’s wasted) My cite is my post. Just kidding, my cite was _in_ my post, “Dark Sun: The Making of the Hydrogen Bomb” by Richard Rhodes. IIRC, regarding physical limits, there was a limit to fission bombs, but not to hydrogen bombs. The H-bombs you can just keep making more and more powerful. The practical limit you come across there (again, IIRC) is that you eventually end up blowing a chunk of atmosphere into space, I _think_the size of Pennsylvania, and if you make the bomb more powerful, you simply end up shooting off the same-sized chunk faster. Of course, as soon as reach the level that a chunk of atmosphere that size is flying into space, thats going to fuck up the Earth pretty bad. ---
**Author:** ![Malacandra](https://avatars.discourse-cdn.com/v4/letter/m/45deac/32.png) [@Malacandra](https://boards.straightdope.com/u/Malacandra)\ **Post date:** [December 12, 2005, 3:44pm UTC](https://boards.straightdope.com/t/how-would-fusion-based-weapons-be/334928/30 "2005-12-12T15:44:57Z")
> [@Pushkin](#): > > The [Tallboy](http://en.wikipedia.org/wiki/Tall_Boy) (5,200 lb explosive, 12,000 lb weight in total) and the [Grand Slam](http://en.wikipedia.org/wiki/Grand_Slam_bomb) (9,135 lb explosive, 22,000 lb weight in total.) I know. I converted to nice round tons for the convenience of the reader. > [@Pushkin](#): > > IIRC from browsing around online, the Grand Slam was the largest conventional bomb dropped, but the US had a larger one built for the purposes of psychological warfare (or maybe they just didn’t get round to using it.) Yeah, yeah, they build _everything_ bigger and better in America. :rolleyes: 😃 The real breakthrough with fusion-powered weapons won’t come until we can devise a means of sustaining a reaction in a small hand-portable device (if we ever can). With a power supply like that, it would probably be feasible to produce a weapon based on the principle of emitting a controlled beam capable of causing a cessation of organic functions. There was much speculation on this topic towards the close of the first quarter of the last century - about 75-85 years ago. ---
**Author:** ![Pushkin](https://avatars.discourse-cdn.com/v4/letter/p/ee59a6/32.png) [@Pushkin](https://boards.straightdope.com/u/Pushkin)\ **Post date:** [December 12, 2005, 4:14pm UTC](https://boards.straightdope.com/t/how-would-fusion-based-weapons-be/334928/31 "2005-12-12T16:14:31Z")
> [@butler1850](#): > > cite on the “all life” issue? Perhaps if you were to stick a really big rocket on the rear end of the moon and slam it into the Earth 😉 There was a suggestion during a BBC documentary on [Project Orion](http://en.wikipedia.org/wiki/Project_Orion), that a larger nuclear weapon than could be launched from a bomber or ICBM could be put into orbit using an Orion space ship. A weapon of suitable size could have what were described as worldwide atmospheric effects. ---
**Author:** ![smiling\_bandit](https://avatars.discourse-cdn.com/v4/letter/s/e9a140/32.png) [@smiling\_bandit](https://boards.straightdope.com/u/smiling_bandit)\ **Post date:** [December 12, 2005, 9:10pm UTC](https://boards.straightdope.com/t/how-would-fusion-based-weapons-be/334928/32 "2005-12-12T21:10:36Z")
> [@](#): > > As I remember it, you do start to run up against some physical limits. After a certain “yield” size, you begin to get inefficiencies that don’t really allow you to scale up much more. (The reaction blows away the additional “fuel”, and it’s wasted) I was joking, more or less. ---
**Author:** ![Citizen\_Bob](https://avatars.discourse-cdn.com/v4/letter/c/f07891/32.png) [@Citizen\_Bob](https://boards.straightdope.com/u/Citizen_Bob)\ **Post date:** [December 12, 2005, 10:42pm UTC](https://boards.straightdope.com/t/how-would-fusion-based-weapons-be/334928/33 "2005-12-12T22:42:36Z")
> [@butler1850](#): > > As I remember it, you do start to run up against some physical limits. After a certain “yield” size, you begin to get inefficiencies that don’t really allow you to scale up much more. (The reaction blows away the additional “fuel”, and it’s wasted) Yeah. That’s why you switch to Anti-matter weapons if you really want to smack someone around… _shiver_ I rue the day someone may actually contain enough anti-matter to build and test one of those monstrocities. ---
**Author:** ![633squadron](https://avatars.discourse-cdn.com/v4/letter/6/ee59a6/32.png) [@633squadron](https://boards.straightdope.com/u/633squadron)\ **Post date:** [December 13, 2005, 12:25am UTC](https://boards.straightdope.com/t/how-would-fusion-based-weapons-be/334928/34 "2005-12-13T00:25:56Z")
> [@Revtim](#): > > What are fusion bombs like? Scary as fuck. A good book about them is “Dark Sun: The Making of the Hydrogen Bomb” by Richard Rhodes. They were turning islands into underwater craters with these things. IIRC, they had the technology in the 50’s to make a hydrogen bomb so powerful you deploy it by throwing it in your backyard, because it’ll destroy all life on Earth, including your target, no matter where you detonate it. There are some limits to the explosive yield of a fission bomb, while a fusion bomb can be made arbitrarily large. The US originated the slang of calling a fission bomb an “A-Bomb” (atomic bomb) and the fusion bomb a “H-Bomb” (hydrogen bomb). Early H-Bombs often “ran away”, generating much greater than expected explosive yields. The scientists had not yet learned to evaluate and quantify all the fusion reactions that went on. This led to a lot of unintentional cratering. The first H-Bomb explosion “Mike” (at Eniwetok Atoll) wiped out the entire island and created a 1/2 mile hole 200 feet deep, because it was a large non-deliverable device done for mostly research purposes. The whole unit was nearly 3 stories high and sat at ground level. The yield was roughly 1.5 megatons, as I recall, which is about 1000 times the yield of the Hiroshima bomb. The fireball alone from that bomb would have wiped out the entire city of New York. The modern H-bombs deployed by the US are in the 550-kiloton range. They’re also quite small. I very much recommend Richard Rhodes two books “The Making of the Atomic Bomb” and its successor “Dark Sun”. ---
**Author:** ![1010011010](https://avatars.discourse-cdn.com/v4/letter/1/ea666f/32.png) [@1010011010](https://boards.straightdope.com/u/1010011010)\ **Post date:** [December 13, 2005, 1:10am UTC](https://boards.straightdope.com/t/how-would-fusion-based-weapons-be/334928/35 "2005-12-13T01:10:51Z")
> [@Bryan Ekers](#): > > My question was about the hypothetical practicality of a ship-based fusion reactor. Would it have to refueled more often than a fission-based vessel, reducing operational efficiency? Fission based vessels refuel on a schedule that stretches to decades… and core lives are only getting longer as the designs improve. The major selling point is that it’s a relatively small, stable, and self-contained power plant that just keeps going and going and going. Fusion offers none of those advantages. > [@Bryan Ekers](#): > > For that matter, could a future fusion supercarrier have a system built in that extracts heavy water from seawater, allowing it to fuel itself? Better yet, make a fission/fusion hybrid powerplant that purifies seawater and then bombards it with neutrons in the fission plant to _make_ heavy water as feedstock to the fusion reactor! You might be able to make a big sea-going fuel plant that chugged around in a circle stockpiling harvested/manufactured deuterium, He-3, et al… but it would probably be a bad idea to try to make it also function as a warship. ---
**Author:** ![Tuckerfan](https://avatars.discourse-cdn.com/v4/letter/t/eada6e/32.png) [@Tuckerfan](https://boards.straightdope.com/u/Tuckerfan)\ **Post date:** [December 13, 2005, 2:31am UTC](https://boards.straightdope.com/t/how-would-fusion-based-weapons-be/334928/36 "2005-12-13T02:31:50Z")
> [@633squadron](#): > > The first H-Bomb explosion “Mike” (at Eniwetok Atoll) wiped out the entire island and created a 1/2 mile hole 200 feet deep, because it was a large non-deliverable device done for mostly research purposes. The whole unit was nearly 3 stories high and sat at ground level. The yield was roughly 1.5 megatons, as I recall, which is about 1000 times the yield of the Hiroshima bomb. The fireball alone from that bomb would have wiped out the entire city of New York. Not unless [NYC’s gotten a lot smaller.](http://www.pbs.org/wgbh/amex/bomb/sfeature/1mtblast.html) > [@](#): > > Radius: 7.4 miles > 1 psi > > Residences are moderately damaged. Commercial buildings have sustained minimal damage. Twenty-five percent of the population between the 2 and 1 psi rings have been injured, mainly by flying glass and debris. Many others have been injured from thermal radiation – the heat generated by the blast. The remaining seventy-five percent are unhurt. [Using lasers to simulate nuclear fusion bombs.](http://www.newscientist.com/article.ns?id=mg18825284.900&feedId=nuclear_rss20)[Official site for multinational fusion reactor project.](http://www.iter.org/) [Previous page](https://boards.straightdope.com/t/how-would-fusion-based-weapons-be/334928.md?page=1)