Archived posting to the Leica Users Group, 2003/09/09
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]At 02:54 PM 9/9/03 -0400, Saganich, Christopher/Medical Physics wrote: >Heisenberg didn't understand fast neutrons yield and didn't solve the diffusion equation until a few days after Hiroshima. > Chris It is quite a bit deeper than that. The Germans made several mistakes, the most obvious being the choice of deuterium as a damper when graphite was preferable from both availability and engineering reasons. They also grossly over-estimated the amount of Uranium-235 necessary to make a bomb - -- the actual amount is something on the order of 40 or 50 pounds (20 to 25kg) but the estimates prepared by Hahn indicated that the critical amount would have to be around 2000 pounds (1000kg). And there was only one particle accellerator of any capability in all of occupied Europe, as opposed to something like 10 in the US and three in the UK. Heisenberg informed Speer in early 1944 that it would be impossible to produce a bomb within the time necessary to aid Germany in the War, and Speer shut the project down, diverting the accumulated uranium for use in anti-tank shells when the German suppy of tungsten from Spain was cut off following D-Day and the liberation of France. Heisenberg and his cronies were taken into British custody and were held for a year or so after the War at Farm Hill in the UK. Their private conversations were taped, and the transcripts have been published. These make it clear that neither Hahn nor Heisenberg were avid Nazis and that they were both shocked to learn that the US had produced a successful bomb - -- they had thought that their incarceration was to use them to make bombs for use against the Soviet Union. Marc msmall@infionline.net FAX: +540/343-7315 Cha robh bąs fir gun ghrąs fir! - -- To unsubscribe, see http://mejac.palo-alto.ca.us/leica-users/unsub.html