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View Full Version : Scarey diagram...Hitler's nuke



banquo's_bumble_puppy
2005-Jun-02, 10:46 AM
http://www.spacedaily.com/news/nuclear-blackmarket-05s.html

Swift
2005-Jun-02, 01:11 PM
I'm not sure why this is scarey. Is it the thought that Germany was that much closer to having a nuclear weapon during WWII? Even if they had a working design (and I can't tell from that picture or with my knowledge) that is a long way from a working weapon.

Eta C
2005-Jun-02, 02:00 PM
I tend toward the skeptical side. The schematic appears to show a uranium bomb similar to "Little Boy" which was dropped on Hiroshima. This type of bomb works by shooting a slug of enriched (U-235 enhanced) uranium into another, larger, piece. This assembly creates the supercritical mass and the explosion. The long length of the bomb in the diagram suggests the gun barrel. This is one obvious approach and is easily sketched out. It was the first one the Manhattan Project speculated on as Robert Serber's Los Alamos Primer shows. (For those unfamiliar with the Primer it is based on the lectures given as the team first gathered at Los Alamos. It gives a good indication of the Allies' state of knowledge at the start of the Manhattan Project). A sketch, however, is a long way from a working weapon.

The article mentions recorded conversations. After the German surrender most of the scientists working on the project (including the director Werner Heisenberg) were captured by British and American troops. They were taken to an estate in England and interrogated. Their quarters were bugged and their unguarded conversations recorded. Their reactions to the news of the bombing of Hiroshima are telling. They are ones of surprise that the Allies were able to construct a bomb. Even given the ambiguity of Heisenberg's later comments (where he hinted that he purposfully slowed the program) the candid reactions indicate how far off they were from building a working weapon.

And they were off. As the article notes, they mis-calculated the critical mass. They never built a working reactor. There is no evidence of the massive enrichment plants required to produce enhanced uranium (for an idea of what's required, look for some photos of the Oak Ridge plant built for the Manhattan Project. That sort of thing is hard to hide). Likewise, any test site would have been noticealbe. The western allies sent teams of scientists in uniform all over Germany looking for sites just like this (the so-called Alsos mission. They found plans, and some small scale test reactors, but nothing resembling Oak Ridge, Los Alamos, or Trinity. (The August 95 issue of Physics Today has several articles on the German bomb project. It's worth searching out if you're interested.)

So, on the whole, I don't think these two historians have anything new that requires re-writing the history of the German nuclear project. In the Russian archives they found a sketch of a possible bomb mechanism that just about any physicist could have drawn in 1942 or 43 and extrapolate out to tests for which there is no physical evidence.

Sammy
2005-Jun-02, 03:37 PM
I think Eta C's analysis is spot on.

I would add just two points. First, even if the Germans had possessed the knowledge to design a bomb, they simply did not have the industrial base to build one. The Manhattan Project built giant manufacturing facilities all over the country, plus drew heavily on the existing industrial base. The project budget was several billion dollars. I don't think they could have supported such an effort. And, nobody was bombing us!

Second, because of Nazi racial policies, Germany lost significant numbers of their nuclear physicists to us. German work in this area was slowed for several years bcause of Hitler's personal position that nuclear physics was "Jewish physics."

frogesque
2005-Jun-02, 07:54 PM
Conventional wisdom has it that the Allies were far ahead of Germany in weapon design but that Germay was far ahead in rocket design. Germany may have wanted a super (nuclear) bomb but didn't have access to either the technology or mineral resources to construct one.

Just as well, if the Allies had the rocket technology or Germany the nuclear know-how then WWII would have been much more destructive than it was

Argos
2005-Jun-02, 08:33 PM
What about this extraordinary claim from PhysicsWeb (http://physicsweb.org/articles/world/18/6/3/1), linked by SpaceDaily:


Working with the journalist Heiko Petermann, RK discovered that a group of German scientists had carried out a hitherto-unknown nuclear-reactor experiment and tested some sort of a nuclear device in Thüringia, eastern Germany, in March 1945. According to eyewitness accounts given at the end of that month and two decades later, the test killed several hundred prisoners of war and concentration-camp inmates. Although it is not clear if the device (figure 1) worked as intended, it was designed to use nuclear fission and fusion reactions. It was, therefore, a nuclear weapon.

frogesque
2005-Jun-02, 09:18 PM
What about this extraordinary claim from PhysicsWeb (http://physicsweb.org/articles/world/18/6/3/1), linked by SpaceDaily:


Working with the journalist Heiko Petermann, RK discovered that a group of German scientists had carried out a hitherto-unknown nuclear-reactor experiment and tested some sort of a nuclear device in Thüringia, eastern Germany, in March 1945. According to eyewitness accounts given at the end of that month and two decades later, the test killed several hundred prisoners of war and concentration-camp inmates. Although it is not clear if the device (figure 1) worked as intended, it was designed to use nuclear fission and fusion reactions. It was, therefore, a nuclear weapon.

Yeah, I read that. Even at this late stage if there were nuclear materials involved I would assume that some of the radiation and by-products would still be around. A series of conventional (initiation) blasts at a concentration camp would easily kill that number of people so I'd want further evidence, including ground data, before I went too far down that road.

Walrus
2005-Jun-02, 09:18 PM
I've been extremely skeptical since I first heard of this book some months ago. It contradicts everything generally accepted about the Nazi atom bomb program. As for the idea the Germans tested a bomb, no-one seems to be able to explain how the Germans would have produced the fissible material for it (I grew up in Oak Ridge, and I can tell you that the technological investment required for refining U-235 is non-trivial. The idea that "a handful" of scientists somehow managed to create this infrastructure without historians noticing is absurd.) Professional historians haven't taken to the book at all, and I suspect it will be remembered like Gavin Menzies' 1421: as sensationalistic pseudo-history for the mass market. Here's a Spiegel article about the book:
http://service.spiegel.de/cache/international/spiegel/0,1518,346293,00.html

V-GER
2005-Jun-02, 09:31 PM
Even if this were true, to turn the tide of war, they would have needed quite a lot of nukes, and something to take them to their targets, namely the US... At that stage of the war, destroying one city wouldn't have benefited them at all, just add to the destruction of their own cities.

Donnie B.
2005-Jun-02, 10:10 PM
It's a small point, but if the caption in the article is correct, the bomb as drawn wouldn't have worked.

It's clearly a drawing of a gun-type device, yet the caption states that it shows a Plutonium weapon. But the work at Los Alamos proved that Pu was unsuitable for a gun design. Contamination from other isotopes (unavoidably produced in the reactor along with the desired 239Pu) makes it impossible to form the supercritical mass without a "fizzle".

In other words, the Germans would have had to develop isotope separation technology to make a gun bomb, whether using 235U or 239Pu. It's clear they never came close to that.

And as Eta C states so eloquently, it's a very long way from a sketch to a working gadget -- the Manhattan Project had equivalent drawings in 1942, three years before Trinity.

Sammy
2005-Jun-03, 01:59 AM
The "German bomb test" sounds like malarkey to me. The give-away is this quote:


....it was designed to use nuclear fission and fusion reactions. It was, therefore, a nuclear weapon. (emphasis added)


Fusion! It took us until the 50s to build a fusion device, using a fission device to ignite the reaction. I don't see a "handful" of people, with no industrial base, doing it in 1945.

Someone's fantasy!

ktesibios
2005-Jun-03, 02:02 AM
In addition to everything above, I think I may have spotted an anachronism in that drawing.

It clearly labels the active material as "plutonium". So far, not bad, the word is the same in English and German.

But...
The discovery of element 94 was announced in late January 1941. However, the name wasn't proposed by the discoverers until early 1942, at which time the USA and Germany were at war and American nuclear research was already under a heavy blanket of secrecy. One of the clues that led the Soviets to conclude that fission research was worth following was the complete disappearance of nuclear physics related papers from American scientific journals before the USA enetered the war.

So, if that diagram was drawn during the war, how did the person who drew it know the name of element 94?

Eta C
2005-Jun-03, 02:26 AM
In addition to everything above, I think I may have spotted an anachronism in that drawing.

It clearly labels the active material as "plutonium". So far, not bad, the word is the same in English and German.

But...
The discovery of element 94 was announced in late January 1941. However, the name wasn't proposed by the discoverers until early 1942, at which time the USA and Germany were at war and American nuclear research was already under a heavy blanket of secrecy. One of the clues that led the Soviets to conclude that fission research was worth following was the complete disappearance of nuclear physics related papers from American scientific journals before the USA enetered the war.

So, if that diagram was drawn during the war, how did the person who drew it know the name of element 94?

I couldn't quite read the fine print, but this is clearly a faulty design if it calls for the use of Pu in a gun-design bomb. Even if the Germans had isolated sufficient Pu, even if they had built the thing, it would not have exploded. Pu-239 is too radioactive to initiate this way. The bomb would have prematured (or fizzled) before a full critical mass was assembled. If the sketch is real (which the use of the term "Plutonium" seems to indicate against) then it further demonstrates how little the German researchers understood what was required for a critical mass and how quickly the assembly had to occur.

The Manhattan Project scientists understood this (check the Los Alamos Primer) which is why the Pu bomb used implosion to assemble a critical mass rather than a gun. Since this was a riskier and uncertain design, it was tested (at Trinity). The design of Little Boy, the U-235 bomb, was well understood so it was not tested before its first operational use.

mickal555
2005-Jun-03, 02:34 AM
The page is riddled with pop ups :evil: :evil:

ktesibios
2005-Jun-03, 02:58 AM
IIRC, the problem with using gun assembly with plutonium isn't the properties of Pu239, it's Pu240. This is found in plutonium produced from uranium in a fission reactor.

Bombarding U238 with neutrons produces U239, which decays into Np239 which in turn decays into Pu239. So far, so good. But the continued neutron bombardment of Pu239 produces some Pu240.

Pu240 has a tendency to fission spontaneously, releasing neutrons. These neutrons make it necessary to assemble the supercritical mass extremely quickly; otherwise the neutron background of the material will trigger a premature chain reaction, resulting in a fizzle.

As long as the only Pu available to American researchers was milligram quantities produced by cyclcotron, the idea of a gun assembly at 3000 fps appeared feasible. It wasn't until reactor-produced Pu became available that the Pu240 problem was discovered.

Since the Germans never got near to getting a self-sustaining chain reaction in uranium going, they wouldn't have had any opportunity to discover the assembly time problems inherent in reactor-produced Pu. Consequently, although we know that this gun-assembly idea wouldn't have worked, they couldn't have known that.

A drawing of a gun-assembled Pu bomb is consistent with what the Germans could not have known before the end of the war. However, I still have doubts about the drawing's authenticity for the reasons I gave above.

Lianachan
2005-Jun-03, 07:28 AM
I think that because the Germans definately held the technological high ground in a few fields, most notably avaiation and rocketry, people generally find it easy to extend this level of expertise to other areas where they were, in actual fact, lagging behind the Allies.

Heid the Ba'
2005-Jun-03, 11:47 AM
What about this extraordinary claim from PhysicsWeb (http://physicsweb.org/articles/world/18/6/3/1), linked by SpaceDaily:


Working with the journalist Heiko Petermann, RK discovered that a group of German scientists had carried out a hitherto-unknown nuclear-reactor experiment and tested some sort of a nuclear device in Thüringia, eastern Germany, in March 1945. According to eyewitness accounts given at the end of that month and two decades later, the test killed several hundred prisoners of war and concentration-camp inmates. Although it is not clear if the device (figure 1) worked as intended, it was designed to use nuclear fission and fusion reactions. It was, therefore, a nuclear weapon.

Given that the Allies arrived in Thuringia in April 1945 if this is true I would have expected them to try it out on the invaders. The atrocities in East Prussia had happened months before and pretty much anything was being used if it even sort of worked.

Eta C
2005-Jun-03, 01:00 PM
IIRC, the problem with using gun assembly with plutonium isn't the properties of Pu239, it's Pu240. This is found in plutonium produced from uranium in a fission reactor.

Bombarding U238 with neutrons produces U239, which decays into Np239 which in turn decays into Pu239. So far, so good. But the continued neutron bombardment of Pu239 produces some Pu240.

Yea, you're on the mark on this one. After I posted last night I did a little of the background reading I've been recommending for everyone else and found I'd somewhat mis-stated the reason Pu won't work in a gun assembly. :oops:


Since the Germans never got near to getting a self-sustaining chain reaction in uranium going, they wouldn't have had any opportunity to discover the assembly time problems inherent in reactor-produced Pu. Consequently, although we know that this gun-assembly idea wouldn't have worked, they couldn't have known that.

A drawing of a gun-assembled Pu bomb is consistent with what the Germans could not have known before the end of the war. However, I still have doubts about the drawing's authenticity for the reasons I gave above.

I found some other interesting tidbits in this morning's reading (again, from Serber's book). The bulk of the Manhattan Project's spending went to the U-235 enrichment program at Oak Ridge. Even with that massive effort (which had no apparent equivalent in Germany) the quantity of enriched uranium was sufficient for only one bomb (hence another reason why Little Boy was not tested. It was a one-of-a-kind weapon). Without the development of implosion assembly for the Pu bombs, only the one would have been completed by the end of the war.

All of this makes the claims of a German test very implausible. They had no knowledge of the requirements for a Pu bomb (not to mention no way of making Pu), and there's no evidence of the massive effort required to generate the enriched uranium for even a single gun assembly bomb. I for one can't see where they would have gotten the necessary material.

Donnie B.
2005-Jun-03, 01:04 PM
IIRC, the problem with using gun assembly with plutonium isn't the properties of Pu239, it's Pu240. This is found in plutonium produced from uranium in a fission reactor.
Exactly. That's why I mentioned isotope separation. You could, in theory, "enrich" the Pu (that is, remove the 240Pu) but that would be even more difficult than separating 235U from 238U. Or you might find some way of assembling the subcritical masses much faster than with a gun-type high explosive charge, but that too would be extremely difficult -- perhaps impossible in a practical weapon. (I'm thinking here about rail guns and such.)

The anachronism question is interesting. I hadn't looked at the larger version of the drawing before my previous post. It's at least possible that the drawing was labeled some time after the war, but that seems quite unlikely -- who would have had access to it? Perhaps some captured German physicist in a secret Soviet research lab? Or the labels might have been applied recently, but the old-fashioned typeface seems to contradict that (it looks like a 1940's-era manual typewriter font, complete with variations due to different pressure on different keys).

So, it would seem that the drawing is either an early "concept" sketch with labels added later, or a modern fake. Either way, it doesn't show a practical device. The Germans were no closer to usable nuclear weapons than we previously thought.

Is it possible that the so-called nuclear test was of a radiation weapon -- a "dirty bomb"? Personally, I doubt it. That would have required some means of producing radioactive material in bulk, i.e. a reactor. We know that the German program was constructing a test reactor, but it never operated for lack of heavy water due to the destruction of the Norsk Hydro heavy water plant (by commando raids and bombings, and finally the sinking of the ferry carrying the remaining stocks of heavy water). Even if it had operated, it was too small to produce much radioactive material.

ktesibios
2005-Jun-03, 03:50 PM
The USA took the possibility of a German "dirty bomb" seriously enough that there was a section of the Manhattan Project devoted to detecting any enemy use of a radiological weapon. It was codenamed "Peppermint". They developed portable Geiger counters for use in surveying areas where the use of such a weapon was suspected; these were sent to Allied capitals via diplomatic pouch and officers trained in their use were sent abroad under the usual assortment of covers. American military medical units were ordered to report any cases of illness with certain specified symptoms and units involved in photography were ordered to report any unexplained fogging of film. Apparently no evidence of radiological weapons use was ever found and Peppermint was disbanded before the end of the war.

Fortunately, without a working reactor, producing significant quantities of the really nasty stuff is very difficult. Most of the radioactive substances available in quantity in nature, like uranium and thorium, are more in the nature of long-term health hazards than killers fast-acting enough to be useful in war.

It's hard to imagine Hitler muttering "they can kill me, destroy my Reich, but I'll have my revenge. Just wait- in twenty years the spike in cancer rates in certain demographics will be statistically significant!"

Donnie B.
2005-Jun-03, 04:50 PM
It's hard to imagine Hitler muttering "they can kill me, destroy my Reich, but I'll have my revenge. Just wait- in twenty years the spike in cancer rates in certain demographics will be statistically significant!"
Not in those terms, no. But given the man's penchant for scorched-earth policies and "hold to the last man" military tactics, I wouldn't have put it past him to try to poison the lands his troops left behind during the retreat -- up to and including German territory. "I can't have it, so nobody can" -- now that I can imagine him thinking. But in Deutch.

All in all, I'd have to say it's a good thing the Third Reich never got close to nuclear capabilities. (This may be the understatement of my lifetime...)