Talk:Thermonuclear weapon/Archive 1

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Suggestions

1. That the sentence about Ivy Mike's impracticability be reenforced, from "The "Ivy Mike" device was far too large to be dropped" to "The elaborate refrigeration plant necessary to keep its fuel liquid meant Ivy Mike was too heavy and too complex to be of practical use." or something similar.
2. That a bit of explanation be added to W-88 revelations. The article says its primary is oblong (IMO "oblate" is a better word for this than "oblong", as "oblong" means "rectangular" to most people) and that W-88 is intended for MIRVs. I think we should add why it's oblate, and why this is such a big deal. My understanding of this is that the diameter of the MIRV is limited by the diameter of the primary - if you can make an oblate primary work properly, then you can get the same bang from a smaller diameter MIRV or missile, which gives you nicer characteristics for that missle (faster, better gas milage, etc.). The reason an established nuclear power might be thought to want to steal info on W-88 (it's not like China doesn't know how to make A bombs already) is that the calculations needed to get a nonspherical primary to explode efficiently are orders of magnitude harder than those for a spherical primary.
3. The article isn't entirely clear about this: should it mention that the US had already exploded a boosted device (Greenhouse George) before Ivy Mike, so that no-one had lingering doubts that the secondary wouldn't light? The article does mention boosting, but for the US program it's not clear that boosting came before the super (the wording for the Soviet program is clear in that respect).

-- Finlay McWalter | Talk 13:37, August 4, 2005 (UTC)

Good suggestions -- I'll try to incorporate these in and clarify what is not clear. --Fastfission 12:46, 5 August 2005 (UTC)

I think I've implemented all of these suggestions. --Fastfission 17:20, 6 August 2005 (UTC)

Split the article

In my humble opinion... The history stuff should be split into a separate article, with this article containing a shorter summary and link. This article has just gotten too big. Georgewilliamherbert 06:41, 14 August 2005 (UTC)

Two small issues

Both in the "Basic principle" section:

• "When fired, the plutonium and/or uranium-235 core would be compressed" Is it really possible to build a uranium implosion bomb? Is there any reason to suppose anyone has ever built a teller-ulam fusion bomb with a U235 primary?
• "unenriched uranium-238" seems redundant, and confusing (there's really no such think as "enriched U238", so surely there can't be such a thing as "unenriched U238". Shouldn't this just read either "uranium-238" or "depleted uranium"?

-- Finlay McWalter | Talk 02:47, 14 January 2006 (UTC)

First question: Yes, Uranium implosion has been widely discussed. It's a lot easier to do that Plutonium implosion, since U-235 has so much fewer random neutrons generated and the risk of predetonation goes way down. Including the metalurgical issues with Plutonium, it's considered a much better long-term stable bomb design approach, in fact... U metal stays that way, in its standard phase, as far as we know essentially forever without suffering physical degradation or phase changes, as long as you protect it from oxidization.

Second question: I think I agree that the phrasing has gotten bad. Natural, unenriched Uranium is a valid choice there, as is "U-238", or "Depleted Uranium". Unenriched + U-238 is a nonsequitur. Georgewilliamherbert 03:06, 14 January 2006 (UTC)

• And on point 1 -- I believe that it is thought that most modern cores are composite u-235/pu cores. More bang for the buck or something like that. --Fastfission 02:41, 10 March 2006 (UTC)

Recent edits

While I appreciate User:Bockspur's enthusiasm, I'm not so hot on all of the edits he/she recently made.[1] I feel they have simply made things more confusing, dressed them up in more complicated (but in the end, not meaningful) language, and much of it is unsourced. The only source added is a paper which nobody outside the classified community has seen, which doesn't help anybody very much, and I suspect Bockspur has not seen it either. But before reverting I thought I'd solicit a second opinion. --Fastfission 02:41, 10 March 2006 (UTC)

Bockspur replies10th of mar 06:outside of the classified community?

the paper is not that restricted, merely it's not currently availible on the internet or in most libraries. there is nothing ground shaking in the paper, in fact if you were going to use it as a reciepe to make a fusion device you would definetely fail. The paper outlines two key elements for compressing the secondary: the use of soft x-ray radiation proposed by teller as opposed to particle compression by ulam and the concept of ablation. unfortunately teller makes the mistake of assuming that he can bounce the soft x-rays of the interior of the casing like ping pongs. Later someone else would correct this with the hohlraum concept. Also, the use of a second fission source inside of the the secondary to act as a neutron source and to ignite the compressed but relatively cool dueterium liquid is completely missing in the paper. This too would come later.

The paper use to be availible at the library of the university that use to manage LL, take a wild guess where that was. I think some undergrad must have stolen it; technically the paper is classified but for all purposes next to useless other than to point how brillant teller was.

• Riiight. You've seen the classified paper but nobody else has. Your library had a copy of it. Take a look at our policy on No Original Research and Verifiability. --Fastfission 05:28, 11 March 2006 (UTC)

Just because you haven't seen something doesn't make it imaginary.If you would like to get a copy make a fia request, i personally see no reason to reject one for such an aged document. but , as i said earlier you'll be a little disappointed when it doesn't turn out to contain much that can't be done with pencil a piece paper calculation. kid i have a Phd in physics, and a masters in applied math and am working on a phd in math; which is an order of magnitude harder than physics. I've never written a NPDE code for a nuclear device but i have used very similar integrator schemes to run icf simulations in grad school. And yes we read everything in the library hoping for a break that would make the lab projects easier. But , I'm sure that i'm not alone in that boat and others have probably had access to more pertinint information, but , until those people show up to edit my work, you'll just have to be content with my chicken scratchings, ok kiddo.

• Please see our Verifiability policy. No references can be given that cannot be verified or confirmed. Hard-and-fast rule, and you can make up all sorts of noise about how you have a PhD or secret access or whatever (every crackpot suddenly becomes a PhD on here, it seems) but it doesn't go into the article, simple as that. --Fastfission 00:46, 13 March 2006 (UTC)

DOE statements

One thing I don't understand from reading the article is, why does the DOE keep declassifying these pointless little statements? What's the point? Who benefits? --220.111.92.12 15:38, 23 April 2006 (UTC)

Several reasons.

• Much of the technology and information ends up being dual-use, and eventually the other, unclassified use ends up needing to have some sort of reference back in to the nuclear weapons usage.
• Much of the information accidentally or informally leaks out. Once it's been revealed, non-DOE experts can confirm its accuracy by analysis, and eventually it becomes so well known that continuing to classify it is hard.
• Some of the information is disclosed due to its relevance to other issues, such as explosives safety, health of nuclear weapons workers, etc.
• Some information becomes so old and obsolete that classification is pointless.
• Finally, a lot of the info that's covered under Restricted Data is pretty silly to have classified in the first place, and is eventually just released.

Georgewilliamherbert 23:48, 24 April 2006 (UTC)

"Dark Sun" description of Mike device

The description of the Ivy Mike device within this article does not quite agree with that given in "Dark Sun". Within Chapter 24 there is a series of five figures showing the sequence of events within the device. The caption accompanying the second figure states that "X rays from the primary vaporize polyethylene lining of Mike casing and heat it to a plasma. Plasma reradiates longer wavelength X rays that ablate surface of secondary pusher, causing rocket effect that implodes secondary, compressing and heating deuterium to fusion temperature and imploding fission sparkplug". This quite clearly states the presence of polyethylene and not polystyrene, as claimed in the article. The polyethylene is a source of plasma although compression of the secondary is by ablation of the pusher, not radiation from the primary. RegIP 16:51, 16 August 2006 (UTC)

I would have to check again but I'm pretty sure that Rhodes actually includes two slightly different descriptions of how it works in the book, something of a contradiction in any case. --Fastfission 13:11, 1 February 2007 (UTC)

"Expiration" of Hydrogen-warheads??

Tritium has a half life of just 12 years, so to maintain a viable warhead, doesn't this mean that the tritium in hydrogen weaponry must be continually replenished with new tritium every 6 months or so? Wouldn't this require the existence of processing facilities to manufacture additional tritium near the warhead's holding areas? — Preceding unsigned comment added by 152.3.99.13 (talk) 18:55, 3 March 2007‎

Why do you suggest six months? The artcile on the WE177 bomb states that replacemnet (relifing) is required after about three years. --ManInStone 12:01, 19 June 2007 (UTC)

6 months, 3 years. I was speculating you'd need the percentage of the tritium to be maintained at nearly the amount originally present in order for it to be viable. Replacing every 3 years means you'd only have ~82% of the tritium originally present at the end of the 3 year cycle- but since that's what the design requires, I suppose it's still a viable warhead at 82%. Still, would this suggest the existence of tritium production facilities near the warhead site? — Preceding unsigned comment added by Tymothy (talk • contribs) 04:04, 15 July 2007‎

My Burden of Sorrow

You are completely correct that the Tritium in Hydrogen Bombs must be regularly replenished.

However, while Tritium is produced in Nature through the Radioactive Decay of many different Isotopes, it is available on Earth only in very small quantities, as of course it has that very short Half Life, and other oxidizes to form water vapor or, being of very little mass, eventually escaping the Earth's atmosphere completely by flying off into [[Outer Space||. Helium is actually produced with far greater abundance through the decay of radioactive elements found throughout the planet, but because Helium - with a certain very rare exception that I'll have to Google up for you later - does not form chemical bonds with anything, despite Monatomic Helium being heavier than Diatomic Hydrogen, far more He escapes into Space than does Hydrogen.

It is for that specific reason - yes I understand I need a citation, but I myself am a Radiation Physicist, so I'll turn up the needed citation Real Soon Now to add to the article itself - that Hydrogen Bombs were tested so often by most members of the "Nuclear Club" throughout the Cold War. It's not that we didn't know how long the Tritium would remain explosive, but that most of our weapons designs were quite sophisticated so as to facilitate what the Scientific, Military and Disarmament Communites cheerfully refer to as "Delivery".

The problem with Delivery is that the straighforward designs for all three different types of nuclear weapon - the Uranium Assembly Bomb, the Plutonium Implosion Bomb as well as the Two-Stage Plutonium Implosion Hydrogen Bomb are very large, very heavy and so not amenable to being, uh, "Delivered" to their waiting, uh, "Recipient" with much chance at all of the Recipient being quite overcome with Joy that their beloved friends, family, classmates and colleagues were so incredibly thoughtful as to throw them a Surprise Party for their Birthday.

Have a look at the Unclassified photos of any Bombs in use today. Every last one of them is very, very small, even the H-Bombs. The need to replenish the Tritium is far more important than you would at first expect, because for most of those designs, it is not at all obvious ahead of time whether the Bomb will actually detonate upon Delivery, produce a Subcritical Reaction known to the Weapons Community as a Squib Explosion, or fail entirely to go off at all.

But it just wouldn't work to actually produce the Tritium close to the actual locations of the Bombs that are awaiting orders to attack. That's because we have so many Bombs, each of which requires so much Tritium - Deuterium as well - that one requires a whole bunch of Nuclear Reactors to have any hope of obtaining enough of the stuff.

The other problem is that, the designs of the Bombs now being so subtle, sophisticated, arcane and delicate, all manner of expensive, precision and highly Classified facilities are required to actually perform the refueling of the Bombs. So in reality, when it comes time to Juice your Rechargeable Battery back up, it's either flown, or transported by truck or rail to the Pantex Plant in Texas, it's Hydrogen explosive completely removed, then immediately replaced with fresh Explosive that is prepared ahead of time for just such an event, then the Bomb is shipped back to That From Whence It Came.

Have a look at the photos of Fat Man and Little Boy. One was a Uranium Assembly Bomb, the other was a Plutonium Implosion Bomb. Both Bombs were so big and heavy that the very largest Bomber possessed by the United States Army Air Corps could only tote one of each, with the elite pilots who sat out the vast majority of the Second World War never, ever being given the least clue as to why they devoted all the years of WWII to training missions in which they dropped very large, very heavy weights out of the [[Bomb bay]bomb bays]] of their B-29 Superfortresses, then more or less on their own to having figure out a way to Split the Scene Completely.

Let's just say that those two or three dozen Cessna Pilots, while never obtaining any manner of detailed understanding, did at least manage clue in to what was planned not for Hiroshima nor for Nagasaki, but downtown Berlin. It's just that we managed to defeat the National Socialist Worker's Party in a purely conventional way before the Manhattan Project's Magic Elixir was quite done cooking.

The bombs dropped on Japan each had a Yield of ten or fifteen Kilotons - that is, they produced a blast about as powerful as ten or fifteen tons of TNT. TNT works and is actually chemically synthesized just like Nitroglycerin, but is far safer to manufacture, store and handle, because it is a Solid at room temperature rather than a Liquid as Nitroglycerin is, as well as occupying quite a deep Thermodynamic Potential Well, thereby requiring a Detonator to get it to go off:— Preceding unsigned comment added by 50.131.200.103 (talk) 04:44, 11 July 2012‎

Castle Bravo "worked far better"

The article states:

"The liquid deuterium fuel of Ivy Mike was impractical for a deployable weapon, and the next advance was to use a solid lithium deuteride fusion fuel instead. In 1954 this was tested in the "Castle Bravo" shot (the device was code-named the Shrimp), which worked far better (2.5 times) than expected and yielded 15 megatons, the largest U.S. bomb ever tested."

I think it is wrong to say it "worked far better". The reason the bomb exceeded the expected yeild was due to a “fuel breader” thermonuclear reaction which had not been predicted as being significant. The excessive high yield was a disaster which caused extensive contamination of the test site and lead to at least one death aboard the Lucky Dragon fishing vessel from radiation poisoning. The high yield was a result of a design flaw.

--ManInStone 12:23, 19 June 2007 (UTC)

I have substituted a more neutral wording. Roger Hui 14:37, 20 June 2007 (UTC)

Thanks Roger, it reads better now. --ManInStone 08:29, 2 July 2007 (UTC)

The secret of the Hydrogen Bomb

Who refers to the Teller-Ulam design as the "secret of the hydrogen bomb"? In my experience when someone is colloquialy describing a Teller-Ulam device they refer to it as an H-bomb or a thermonuclear weapon. Consider this sentence: "The biggest explosion ever made by man is witnessed in the Pacific when US scientists explode their second secret of the Hydrogen Bomb at Bikini Atoll." Holme053 20:07, 18 October 2007 (UTC)

See History of the Teller–Ulam design#The Progressive case. The design was a secret, the existence and effects of thermonuclear weapons in general obviously were not. --JWB 20:22, 18 October 2007 (UTC)

Tamper-Pusher ablation, does the tamper fission?

After ~3/4 of the tamper is ablated off, the rest being forced inwards with the fusion fuel/spark plug, does that 1/4 of the tamper also undergo fission? --Fxer 19:35, 1 June 2006 (UTC)

Depends on the design. Thermonuclear bombs can be "clean" or "dirty". "Dirty" designs us a fissionable tamper/pusher (or at least tamper), such as U-238, the fission of which typically doubles yield. "Clean" designs use a non-fissionable tamper/pusher (lead, tungsten, in some cases perhaps gold) at lower yield and no fission, but much reduced fallout.

Figuring out what modern weapons are clean and dirty is somewhat difficult, since governments tend not to discuss design details, and since underground testing became standard the fallout isn't available for analysis. Yield to weight analysis suggests the modern compact ones tend to be dirty, though. Georgewilliamherbert 20:40, 1 June 2006 (UTC)

I think what he's asking specifically is that does ablation reduce the amount of material remaining to fission, in the end? I never thought about that aspect of it, myself. --Fastfission 20:51, 1 June 2006 (UTC)

Oh, yeah. The ablation material (for example, 3/4, though it may be more or less) moves outwards and is effectively not part of the tamper fissioning.

Basic H-bombs use a single material for the ablation pusher and tamper. Really creative designs from advanced nuclear weapons nations might use different materials, with one material (say, cheap/safe lead) as the ablation pusher, and another (DU, or even HEU) as the tamper. But to know for sure where the boundary is, you almost certainly have to do an H-bomb test program... Georgewilliamherbert 21:47, 1 June 2006 (UTC)

It shouldn't matter if the outer tamper layers are expanding outward. Fast neutrons are still fast enough to cover the small additional distance. --JWB 20:28, 18 October 2007 (UTC)

It affects whether the neutrons interact with any of the fissionable material or not. If you look into how critical mass scales with density of the material, it goes up with the square of density. The reverse works, too... if you look at the flight path of a neutron, what matters is how many fissionable atoms lie on that trajectory. As the material expands, it expands out (radially away), which doesn't decrease the number of interactions from the core to the tamper gas cloud edge, but also laterally away from the line of flight... which does decrease the number of interactions. The count of atoms along (close enough to) the flight line drops with the change in density. So those fast neutrons are much more likely to escape without interacting with anything. For very very large secondaries the density might still be more than a mean free path thick after pusher expansion, during the secondary burn, but for most compact weapons the pusher atoms are negligible or a very small fraction of the secondary fast fission reactions that follow. Georgewilliamherbert 03:43, 8 November 2007 (UTC)

Neutron Bombardment, Aluminium?

Neutron Bombardment of the lithium deutride - Wouldn't that require something to slow down the neutrons to assist the deutrium to become tritrium? Something like aluminium casing on the inside of the lead / uranium secondary casing? or does the lead casing on the outside of the secondary do a good enough job of slowing down the neutrons? Or is it the Li that does the job? or a combination?

• You should sign your notes (typing four ~ characters in a row gives the name/date signature you see a lot). To answer your question, it's not neutrons being absorbed by the deuterium to make tritium, it's neutrons fissioning the lithium, into tritium, helium-4, and with the Li-7 isotope of Lithium, another free (lower energy) neutron. The original neutron is captured in the lithium nucleus but only briefly. The reactions are described in detail in the Nuclear Weapons FAQ. Georgewilliamherbert 21:14, 30 October 2005 (UTC)

[2] does give the (n,t) cross section for 14 MeV neutrons as relatively low, in fact only 35% of the cross section for (n,2n). Scattering cross sections are much higher, so the lithium deuteride is moderating many of the fast neutrons before they can be absorbed, although multiple scattering would seem to raise the risk of the neutron exiting the compressed LiD. The secondary tamper-pusher must be contributing by scattering back some moderated neutrons (it should not be a good moderator itself) and/or fissioning under 14 MeV neutrons and returning 1-2 MeV fission neutrons to the LiD. If the latter is the dominant source of neutrons for lithium fission (and if most of the lithium is actually fissioned to tritium, instead of most of the deuterium being consumed by D-D fusion or a direct Li-D reaction) then this is truly a mixed fusion-fission explosion, rather than independent fusion and fission stages in series. --JWB (talk) 23:52, 12 December 2007 (UTC)

The Foam Plasma Pressure Fallacy

Aaaaarrrrggghhhhhh, not the foam plasma pressure fallacy again! Doesn't anyone read the FAQ anymore? Nuclear Weapon FAQ Sect 4.4.4.2.2, Radiation Channel. The implosion pressure does not come from the filler foam. It's possible to build and fire a Teller-Ulam device with a completely empty radiation channel in the radiation case. The foam is there to retard initial liner and pusher ablation long enough for the energy distribution to even out smoothly. The pressures generated are trivial compared to those required to implode the secondary. What generates the implosion pressure is the ablation (effectively as if it were an in-turned rocket motor) of the fusion pusher layer of the tamper/pusher assembly. A large portion of the tamper/pusher ablates away in this process, leaving a thinner tamper layer up against the now-compressed fuel layer.

I know Moorland's article said that the foam plasma pressure was significant, but Morland wasn't a bomb physicist, and we know a lot more now than we did then. These inaccurate descriptions have got to stop, they're grossly misleading everyone.

I can rewrite the article's implosion description sometime this week, but for now, it flunks peer review on that basis. Sorry. It's not your fault for believing the Morland article, but Morland got that detail (and several others) wrong... Gotta get it right here. Georgewilliamherbert 09:12, 8 August 2005 (UTC)

Per discussion here and on the Peer Review page, I intend to redo the implosion physics section and correct the foam plasma issue probably Wednesday night, Aug 10. Georgewilliamherbert 02:59, 10 August 2005 (UTC)

Does the outer secondary layer expand outwards to fill the radiation channel? If so, the inner layer of the radiation case should do the same thing, closing the radiation channel. Wouldn't the increasing compression of the light-element plasma oppose complete disappearance of the radiation channel?

By conservation of momentum, outward motion of the outer layer needs to occur to balance inward motion of the inside, as long as the outer layer is expanding nearly freely against lighter plasma. But if the outward layer of the secondary is halted by hitting the inner layer of the radiation case, this is no longer necessary. --JWB (talk) 23:27, 12 December 2007 (UTC)

Yes, but the timing is everything.

The objective of the radiation case is to last long enough to efficiently evenly distribute the primary energy around the inside of the radiation case. Once everything is close to thermal equilibrium, that job is done, and where it goes doesn't matter.

What does matter is that the distribution happen faster than things start to block off the channel, and/or disrupt the containment provided by the radiation case.

Preventing the channel from being blocked is the role of the foam filler - it is heated to plasma by the X-ray photon gas, and the pressure of that plasma retards the expansion of heated radiation case inside wall and outside wall of the pusher (and anything else in the radiation case). It just has to retard the expansion long enough that the temperature mostly equalizes before the channel is blocked off.

For three stage weapons, you care what happens outside the second stage radiation case, within the third stage's radiation case. But for two-stage weapons, once the temperature is roughly equalized, you don't care. That's the case with nearly all weapons in use worldwide today, which are two stage.

What happens from the point of rough equalization of temperature is that the expanding hot pusher layer gas rockets off the pusher/tamper outer surface, meeting the radiation case's remnants (which are expanding inwards and outwards all around as well). You can do a momentum balance and look at the expansion behavior. All of this is highly supersonic, so it doesn't matter that the outer layer of the expanding jet of pusher hits the expanding radiation case remnants; a shockwave from that will propogate back inwards, but not catch up with the implosion of the pusher and secondary fuel. Georgewilliamherbert (talk) 02:05, 13 December 2007 (UTC)

Fair use rationale for Image:Tsarbomb.jpg

Image:Tsarbomb.jpg is being used on this article. I notice the image page specifies that the image is being used under fair use but there is no explanation or rationale as to why its use in this Wikipedia article constitutes fair use. In addition to the boilerplate fair use template, you must also write out on the image description page a specific explanation or rationale for why using this image in each article is consistent with fair use.

Please go to the image description page and edit it to include a fair use rationale. Using one of the templates at Wikipedia:Fair use rationale guideline is an easy way to insure that your image is in compliance with Wikipedia policy, but remember that you must complete the template. Do not simply insert a blank template on an image page.

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BetacommandBot (talk) 02:13, 12 February 2008 (UTC)

Tom Clancy Novels

In the Tom Clancy novel The Sum of All Fears, there is a large amount of information on the construction of H-bombs, which he states is available to the public. He also states that a "sufficiently wealthy individual" could produce a mulit-stage thermonuclear device within 5-10 years. Can anyone confirm this?

DarkLite (talk) 17:09, 1 March 2008 (UTC)

Nobody has publicly announced that they did so, but the South African bomb program only cost a few hundred million dollars, including fissile production, and the design problem isn't that difficult.

See for example The Nuclear Weapon Archive website on the design difficulty question, or the classic Nth Country Experiment. It's technically challenging, but feasible with a few man-years work. Georgewilliamherbert (talk) 00:11, 4 March 2008 (UTC)

Well, that's just fission though. Unless one puts bounds on what "sufficiently wealthy" means, I'm not sure the statement is meaningful. Aside from design questions—which you'd have to do a little testing of a few types to have any confidence in—there's still the material production problem. Is our "sufficiently wealthy" individual running his own plutonium production reactors? Does he know how to make lithium hydride? Does he have his own Hanford, Savannah River, Oak Ridge? If so, sure, I guess it's possible, but you're basically postulating an individual with the resources, scientific infrastructure, and unrestricted use of facilities and land on par with a modestly productive country. I don't think it's terribly plausible. --98.217.8.46 (talk) 16:40, 17 March 2008 (UTC)

Sigma clearance

Yeah - that's why reading this stuff is laughable. Its' one thing to say, hey, I love nukes. This is what I am guessing is going on based on reading a bunch of stuff. Some of you get in here, and talk like you're inside the fence with a sigma clearance. Now, go back and reread how some of you pooh-poohed the need for certain poly products in a weapons platform...

watcher —Preceding unsigned comment added by 206.23.13.115 (talk) 07:09, 19 March 2008 (UTC)

(rolling eyes) Thank you, anonymous from Savannah plant whichever.

I've been working with Carey on and off for more than a decade. Please tell us again what we know and don't know. Georgewilliamherbert (talk) 00:24, 20 March 2008 (UTC)

The "Neutron Gun" reference and speculation really makes me laugh - If the objects in the picture are what I suspect they are, they're EXTERNAL neutron sources (ENS), and wouldn't be found anywhere WITHIN the radiation case, much less in the "Interstage"... From what I understand about the functioning of devices like this (And I've been studying and trying to understand them for the past 10 years), the "interstage" is basically just a sophisticated baffle plate, with a number of channels running through it, each of which has an ablative plug in it designed to "slowly" (a relative term when talking about events such as this) burn away and modulate the flow of energy from the Primary to the Secondary. This allows the energy flow to "slowly" ramp up to give a Secondary a smooth "push", instead of a sudden "hammer blow", giving a much more efficient compression. Personally, I ALWAYS treat anything from organisations such as Greenpeace with extreme care, as they're not the most reliable or impartial of sources, and thir grasp of science often leaves much to be desired!! Emma white20 (talk) 19:36, 25 December 2008 (UTC)

A basic question

Hi, all!

Could anyone tell me how much energy (in ergs) can be released by a h-bomb? Thanks

-metanb —Preceding unsigned comment added by Metanb (talk • contribs) 14:59, 5 July 2008 (UTC)

I will probably get this wrong, but I'll give it a try. My college physics classes were in 1976-1980. :-)

First, H-bombs are "tunable" by design and construction techniques across a very wide range of output.

The smallest H-bomb one I've heard of was the "Hood" test, at 70 kilotons. The largest one I've heard of was the Soviet Union's "Tsar Bomba", at 57 Megatons. That's not a typo, it's 57 million tons.

Bomb output is measured in "tons", with a "ton of TNT" being what we're talking about. Generally we start at 1 kiloton for very small A-bombs.

A 1 "kiloton" bomb is very small in the scale of atomic bombs. However, here's the math:

1 kilo = 1000 (of something) 1 ton = 2000 pounds (of something) 1 kilo*ton = 2000 x 1000 = 2 million pounds of TNT going off. Bang!!! Believe me, one pound of TNT going off is very impressive.

Here's from the "The Los Alamos Primer", by Robert Serber.

"The direct energy release is about 170 Mev per atom" (fission)." That's about one hundred million times the energy you'd get from chemical explosions.

"The energy release of TNT is ~~ 4 x 10^10 erg / gram, or ~~ 3.6 x 10^16 erg / ton."

The first hydrogen bomb was codenamed Mike, and went off Nov. 1, 1952. It yielded 10 Megatons.

1 megaton [one million tons] x 3.6 x 10^16 erg, per ton, is 10^6 [a million] x 3.6 x 10^16 erg, giving us 3.6 x 10^22 ergs / megaton.

Mike thus yielded 10 x more, or, 3.6 x 10^23 ergs.

Multiply by 5 or so to get Tsar Bomba.

I hope this is helpful. Please feel free to correct me.

-- thanks, Dave

67.190.176.98 (talk) 01:33, 24 January 2009 (UTC)

Using conventional standard for TNT equivalence, 1 gram TNT = 4184 J:

1 megaton = 4,184,000 gigjoules (or 4.184E022 ergs)

So at the top end, a 50 Mt Tsar Bomba would be 209,200,000 gigjoules (or an ergfest @ 2.092E024)

And so a "typical" modern MIRVed warhead might be 300kt for 1,255,200 gigjoules

And if you accept 15kt as the figure for Hiroshima you get 62,760 gigjoules (or 6.276E020 ergs)

The figures from Serber's most venerable work were rougher, to the tune of about 0.86. Obviously, for ballpark, both work fine--trust me, you'll never notice the difference!

P.S.-- 50 Mt is (or is becoming) the more accepted figure for the Tsar Bomba. The 57Mt figure being the American remote "guesstimate"--the Russian figure is about 50Mt.

Criticality (talk) 03:41, 11 May 2009 (UTC)

Hydrogen VS Nuclear

I've been told this many times, but I want to get it straight in my head. The Hydrogen Bomb--to my knowledge and what people have told me--is a non-nature killing version of the nuclear bomb (meaning it causes no nuclear winter, or leaves the land radiation filled.)

Is this true, or does the Hydrogen Bomb still create such a mess? 76.204.99.26 08:10, 7 November 2007 (UTC)

Disclaimer: I am not a physicist and the following is speculation. First, nuclear winter is thought to be caused by the combustion of vast amounts of flammable material, creating smoke and soot that would block sunlight for a lengthy period. Fusion vs. fission would make no difference in this regard. Second, the Teller-Ulam design specifies a fission primary (with uranium or plutonium) and also fissile material around the secondary, both causing radioactive fall-out. Third, pure fusion, even if possible, produces energetic neutrons and photons that would make other material radioactive. Roger Hui 15:31, 7 November 2007 (UTC)

Fallout is dependent on the amount of fission; you at least have the fission trigger's yield (3% or more of the total), and probably use a fissionable tamper material in the secondary, which (roughly) doubles final yield but increases fission fraction to 50% and thus wildly increases fallout.

Nuclear winter is due to things burning and putting up soot. That's a factor of how much the weapon sets on fire (and how much burns afterwards). It would take a lot of fission bombs to burn a lot of territory and cause a nuclear winter. Thermonuclear bombs have so much more yield that they can cause much larger fires. Georgewilliamherbert 03:47, 8 November 2007 (UTC)

So would it theoreticly be possible by stopping the nuetron and photon escaping or somehow releasing them in a way which would make them non radioactive work. Please do not comment on anything i have got wrong with this just tell me is it possible. —Preceding unsigned comment added by 91.85.203.85 (talk) 15:36, 11 June 2009 (UTC)

It's not possible. There is so much energy involved, enough to vaporize tens of thousands of tons of the strongest materials, that nothing can contain it other than burying it deep in rock. Georgewilliamherbert (talk) 20:05, 11 June 2009 (UTC)