Very interesting read. I read it all, and it looks to me none of the German scientists had any clue that you can build a plutonium bomb. They kept talking about 235 (i.e. Uranium-235), about isotope separation, but not a single hint that you could transmute U-238 into Pu-239 and then make a plutonium bomb.
What's not appreciated about the Manhattan project is that not only the US made a bomb, it made two, meaning two completely different designs. And they were aware of a third one: Glen Seaborg (the discoverer of plutonium) has investigated the feasibility of making a bomb from Uranium-233 [1]
> Seaborg viewed uranium-233 as a potential backup to plutonium-239
So the US could have made bombs of three different designs, it just got confident enough that 2 will work out in the end. Of course, 10 years later (in 1955) it did build and test a U-233 bomb just to see that it's possible.
That’s nightmare fuel: finding out that your enemy is making physics bombs out of elements you weren’t aware of. It’s the plot of an X-Files or something.
What's not appreciated about the Manhattan project is that not only the US made a bomb, it made two, meaning two completely different designs. And they were aware of a third one: Glen Seaborg (the discoverer of plutonium) has investigated the feasibility of making a bomb from Uranium-233 [1]
So the US could have made bombs of three different designs, it just got confident enough that 2 will work out in the end. Of course, 10 years later (in 1955) it did build and test a U-233 bomb just to see that it's possible.[1] https://trace.tennessee.edu/utk_gradthes/2758/