Yeah... B. Arakatsu, Y. Uemura, M. Sonoda, S. Shimizu, K. Kimura, and K. Muraoka: Paper "Photo-Fission of Uranium and Thorium Produced by the r-Rays of Lithium and Fluorine Bombarded with High Speed Protons," Proc.Phys.-Math. Soc.,Japan, 23, 440-445 (1941)
Not wishing to re-open what looks to have become a bit of an acrimonious thread, but since schoolboy nuclear physics has always intrigued me... I had better qualify that last bit... Since I was a schoolboy, nuclear physics has intrigued me but my knowledge is still that of a schoolboy of thirty odd years ago.... I thought all you needed was to ram two 7 pound (3.5 kilo) pieces of uranium 235 into each other at high speed and the instability in the uranium 235 atom would do the rest. Hey presto, a chain reaction and a dirty bomb (though I might be mistaken and it might have been plutonium.... it was a long time ago now!). I think the design was something like this
I thought all you needed was to ram two 7 pound (3.5 kilo) pieces of uranium 235 into each other at high speed and the instability in the uranium 235 atom would do the rest. Hey presto, a chain reaction and a dirty bomb (though I might be mistaken and it might have been plutonium.... it was a long time ago now!). I think the design was something like this... Yep, a "Uranium Gun" device Such as Little Boy.... Have you noticed the gross error that Heisenberg made that stymied the WHOLE German project? "I thought all you needed was to ram two 7 pound (3.5 kilo) pieces of uranium 235 into each other at high speed " "Hahn: I think it’s absolutely impossible to produce one ton of uranium 235 by separating isotopes." Heisenberg as early as his 1943 discussion with Nils Bohr revealed that he had completely overscaled the amount of fissionables required to sustain a reaction. After the war he claimed he DELIBERATELY made this scaling error to halt the German project ....but mid-war when he hit a wall he went to consult Bohr and it was clear THEN - in an unofficial talk between two now peers and former teacher and pupil - unintentionally revealed this error... THAT'S what drove him to his room at Farm Hall for six hours to work the math after the German scientists there heard about Hiroshima and NAgasaki - they couldn't believe the Americans had exploded bombs containing such small weights/amounts of fissionables. They - NONE of them - had thought it could be done down at that "small" bomb weight.
