REALLY Heavy metal work

I'm sure that there are purely mechanical ways of building your gun mechanism that would put some redundancy in. The one that comes to mind first would be load a honkin' big round -- cartridge, primer, powder, and U-235 "bullet" -- that gets automatically loaded into the gun (with interlocks) and won't do s**t outside of it. Perhaps better, have the U-235 in the tube, but keep the explosive physically separate until the minute that it is needed.

But -- the Iranians do appear crazy. Or at least fanatical, which looks like insanity to anyone who doesn't share their particular brand of fanaticism.

Oh, I don't doubt that. I'm not suggesting they just said, "Hey, let's try this by dropping one on Hiroshima!"

I still find it remarkable that they relied on those calculations, when some scientists were still worried that the Earth's entire atmosphere might go up in a conflagration.

It was a lot of predictive science packed into a short time under enormous pressure.

Yes, that's the deal, typical power and research reactors produce

The Manhattan project was truly amazing, they built something that was only a theoretical possibility in just a couple years, in the MIDDLE of a huge war!

Jon

Yes, typically TONS of low-enriched Uranium for a light water moderated reactor. There are some gadgets called water boilers that used really small amounts of dissolved uranium and would go critical on a few kg of it. They made wide pans to store it, and sucked it up into a spherical chamber to make it go critical. If it ever overheated, it would boil off some of the water and drive the fluid back into the wide pan. Well, I'm pretty sure nobody could get one of these licensed to operate today!

Jon

After reading Feynman, Oppenheimer, and others, I find it even more amazing that they built the bomb. So many times they came so close to disaster. And all the number crunching that was done by hand and by primitive calculators. Eric

I've read that they even measured the results of a "Buffon's Needle" trial:

Those primitive calculators were also known as grad students. My aunt Becky was one of them in New York, although they weren't told at the time what the calculations were for.

David

It was done with a high speed switching component that is still restricted.

That's it. i figured that you and maybe Don Nichols would know, but I was waiting to see if anyone else knew. An EE on another group managed to pick up one surplus.

Yes, but krytrons are also a 1940s technology, and far easier to duplicate than say an ultracentrifuge. And I bet one can buy them from non-US sources.

Joe Gwinn

With high speed solid state electronics commonly available who needs ancient tube technology?

The switching time and power levels it can handle still make it a very useful part in trigger applications.

Probably anyone who wants that device to work reliably in a high radiation environment. Ionizing radiation can do all sorts of nasty things to semiconductors. jk

Reading the article about these high speed, high voltage, high current devices tells why semiconductors have not been able to replace the vacuum tube for some applications. I found it very interesting. Not only the vacuum tube technology but the state of the art semiconductor technology too. Eric

No magic there. Still '40s tech. Clearly the Soviet Union, the UK, France, China, India, and Pakistan have managed to produce equivalents. And it's becoming abundantly clear that any information that the Pakistanis hold is accessible to any terrorist who wants it.

It doesn't have to work in a high radiation environment. The high radiation comes _after_ it has worked. And a very short time after the high radiation, it is reduced to vapor.

That's only for soft targets like cities. Hardened bunkers and missile silos rate more than one warhead, also a defensive burst in their path exposes incoming missiles to a very high radiation environment.

v5ddt5

So, you're an expert on building terrorist weapons?