How close were the Germans from building a A bomb.?

What stopped the Germans from building this A bomb and did the loss of heavy water in Norway (i think)have any impact.?

Not at all close. The german physicists, headed by the theoritical physicists Werner Heisenburg, who were developing the bomb had their calculations wring and believed they needed far more U-235 was needed to build a bomb. Their reaction to the dropping of the US bomb was recorder at Farm Hall where they were given information on the mission and their reactions were taped.

Read this for more WW2 German Atomic Weapons Research

Ross

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Von Braun wasn't involved in atomic bomb development correct?

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Correct, Von Braun's area was the rocket or better known as the V2.

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Regards, Richard

That's what I thought.

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without Dr Walter Von Braun and the rest of the German V2 personal we would have had trouble landing man on the moon

He did help us out in the space race. Also I think it's Werner but I may be mistaken.

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Paul Lawrence Rose

Heisenberg and the Nazi Atomic Bomb Project, 1939-1945
A Study in German Culture

http://ucpress.edu/books/pages/8006.html


Just reading this one. Quite interesting except for the first 70 pages which repeat " Heisenberg had it the wrong calculated and after the war he began at once to construct an image of himself as a "pure" scientist who could have built a bomb but chose to work on reactor design instead." After that if gets much better...

Just getting to the 1940´s so we´ll see if they had any useful ideas to go on with though?!

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Seems like the Germans were pretty desperate:

" Heisenberg knew perfectly well in 1945 that there were at least three other official projects aimed at the building of an atomic bomb: The Ardenne laboratory´s work under the joint aegis of the Post office and the Reichsforschrungrat;the Dällenbach project under Reichsforschrungsrat, AEG and Kaiser-Wilhelm-Society auspices, for which he himself had acted as consultant;and the SS bomb proposal of 1944. "

"Heisenberg and the nazi atom bomb project" by Paul Lawrence Rose

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The Post Office building a bomb?

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of creating an atomic weapon, they were on the wrong porch, and looking in the windows of the wrong house. That self-serving claim by Heisenberg that he "sabotaged" the search for and production of the bomb is refuted by a letter to him from his freind Bohr who had read the book upon with the play "Copenhagen" was based. This was the book by Robert Jungk, Brighter Than a Thousand Suns; consequently I think it is only appropriate to include this letter to Heisenberg written by Bohr soon after he had read the book:

"Dear Heisenberg,
I have seen a book, "Stærkere end tusind sole" ["Brighter than a thousand suns"] by Robert Jungk, recently published in Danish, and I think that I owe it to you to tell you that I am greatly amazed to see how much your memory has deceived you in your letter to the author of the book, excerpts of which are printed in the Danish edition.

Personally, I remember every word of our conversations, which took place on a background of extreme sorrow and tension for us here in Denmark. In particular, it made a strong impression both on Margrethe and me, and on everyone at the Institute that the two of you spoke to, that you and Weizsäcker expressed your definite conviction that Germany would win and that it was therefore quite foolish for us to maintain the hope of a different outcome of the war and to be reticent as regards all German offers of cooperation. I also remember quite clearly our conversation in my room at the Institute, where in vague terms you spoke in a manner that could only give me the firm impression that, under your leadership, everything was being done in Germany to develop atomic weapons and that you said that there was no need to talk about details since you were completely familiar with them and had spent the past two years working more or less exclusively on such preparations…."

Then if one reads the 200-odd pages of the 1992 declassified Farm Hall transcripts, there is the moment when Werner Heisenberg and the nine other German nuclear scientists being held at a country house in England hear that an Allied Atomic bomb has devastated the city of Hiroshima.

The Allies' atomic weapon, according to the BBC Home Service announcer, has delivered "as much explosive power as 2,000 of our great ten-toners." Hidden microphones were clandestinely transmitting the voices of the German "guests" to a nearby listening room at Farm Hall, and so we have in the reports a record of their astonished reaction. Heisenberg is heard to "snort" and then responds by flatly rejecting the possibility that the bomb could have been a fission weapon. "Some dilettante in America who knows very little about it has bluffed them," he says. "I don't believe that it has anything to do with uranium."

Even more informative, from any scientist or historian’s point of view, are the intense technical discussions that consumed the subsequent hours and days as the captive scientists tried to puzzle out how their Allied counterparts could have managed to do what they had concluded was beyond reach. Of particular interest, is Heisenberg's informal estimate of the amount of uranium required for a bomb, the critical mass.

Throughout the war Heisenberg continued to believe that many tons of the rare isotope uranium-235, or of plutonium (an impossible quantity for any country to obtain in his estimate) would be needed for a bomb, rather than the tens of kilograms actually required.
"I consider it perfectly possible that they [the Allies] have about ten tons of enriched uranium," Heisenberg says, "but not that they can have ten tons of pure U-235." (the separated isotope)

This faulty estimate, apparently made early in the war and reiterated at Farm Hall, was an error of far-reaching consequence. With an exaggerated notion of the task, the Germans ruled out the possibility that a bomb could be built during the war and instead focused on reactors, which could also be used to generate plutonium for an eventual bomb. A further effect of the mistake was to encourage a false sense of security, which deprived the German project of the kind of urgency that drove the Allies.

To get a chain reaction in natural uranium you need a moderator to slow down the neutrons that are generated from fission. This was widely known in the world of physics. Two moderators were believed to be possible: carbon or "heavy water" (D2O, Deuterium) . Walter Bothe, the leading experimental nuclear physicist in Germany, did the crucial experiment and concluded that carbon in the form of graphite would not work. In America, Enrico Fermi did a similar experiment and concluded that graphite was marginal.

He suspected that an impurity in the graphite was responsible for the problem. Leo Szilard, who was working alongside Fermi, and had actually "patented" the concept of a fission bomb in the mid-thirties, had studied chemical engineering before going into physics. He remembered that electrodes of boron carbide were commonly used in the manufacture of graphite. It was known that one atom of boron absorbs about as many slow neutrons as 100,000 atoms of carbon. Very small boron impurities would "poison" the graphite for use as a nuclear reaction moderator. Szilard therefore went around to the American graphite manufacturers and convinced one of them to make boron-free graphite.

Using this pure graphite as the moderator, the American group achieved a chain reaction on December 2nd, 1942.
The German team, however, felt they needed to use heavy water (Deuterium). Ordinary water contains heavy water at a rate of about 1 part in 5,000 to 10, 000. The two can be separated by repeated electrolysis, which requires large amounts of electric power in close proximity to a water source. The Germans had this at the Hydro Norsk hydroelectric plant in occupied Norway, since that plant had been the first (and only at the time) commercial producer of the Deuterium.

The British alerted the Norwegian underground that heavy water was useful for the war, without telling them why. The Norwegians had already suspected as much, and had smuggled their own "stockpile" of deuterium to France when the German orders multiplied exponentially. When the British SOE altered the underground, courageous Norwegians sabotaged production as best they could, by such diverse methods as adding cod liver oil to the process which cause excessive "foaming" in the plant and delayed the produciton. As a result the Germans had only about half the heavy water they needed by the end of the war.

Despite the shortage of heavy water, Heisenberg continued to work toward a chain reaction to the very end of the war. What else could he have done? Graphite was not an alternative; he had no reason to doubt Bothe's measurement. Bothe was the recognized authority in the field and Germans believed strongly in authority. Even if another German had repeated the experiment, the result would have been unchanged. No German physicist would have consulted a chemical engineer! The barrier between the two disciplines was too large and respect for "authorities" in the field too great. It would have been equally impossible to accelerate heavy water production. To do so would have required additional electric power sources in an already power-constrained economy. Germany's final attempt to build a nuclear reactor failed to go critical for lack of enough materials and time.

This was why he could say with a straight face; "For the present I believe that the war will be over long before the first atom bomb is built." (Heisenberg, statement to Hitler in 1939)

As the head of German research (Heisenberg) could honestly report to Hitler later, in July of 1943 that; "though our work will not lead in a short time towards the production of practical useful engines or explosives, it gives on the other hand the certainty that in this field the enemy powers cannot have any surprise in store for us."

(OPPS)

one can find these excerpts in:

"The Farm Hall Transcripts: The German Scientists and the Bomb."(Aug. 1992).

Or "Hitler's Uranium Club: The Secret Recordings at Farm Hall." [US]: American Institute of Physics, 1995.

ALSOS: The Failure of German Science. London: Sigma, 1947;"Goudsmit, Samuel A. New York: Henry Schuman, 1947


As a cute sidebar, the atomic team sent to Germany to find the atomic efforts and material of the Nazis called themselves ALSOS. It was named that as it is the Greek word for Groves. i.e. the lead-man of the Manhattan Engineering District. Groves=ALSOS. It was picked without the knowledge of General Groves himself however, and on the QT as a sort of joke.

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Happy Trails,
Clint.

On Niels Bohr (Nobel Prize 1922):

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