[stylin_geek]

If memory serves correctly, the first A-bomb that was dropped was built around the barrel of a 6" rifle. I think it had two sub-critical masses of nuclear material at either end, which were driven together by explosives to create critical mass.

[okie01]

"the first A-bomb that was dropped was built around the barrel of a 6" rifle. I think it had two sub-critical masses of nuclear material at either end, which were driven together by explosives to create critical mass."

There was a donut shaped mass of uranium at one end. The gun propelled a disk of uranium, that served to fill the donut hole. An elegant solution...

[Imal]

If memory serves correctly, the first A-bomb that was dropped was built around the barrel of a 6" rifle. I think it had two sub-critical masses of nuclear material at either end, which were driven together by explosives to create critical mass.

Yes. They even used cordite for the explosive trigger, I believe. A very crude, but obviously effective weapon, yielding about a 15-kiloton blast.

Looking at this bomb, Little Boy, and its Nagasaki follow-on, Fat Man, reveals how straightforward basic nuke construction can be if the materials are available. It also shows that you don't need a fancy spherical explosive lens to get results with 90% enriched U-235, although the implosion-type bombs such as Fat Man are definitely much more efficient and require less material for a chain reaction.

The most significant problems facing prospective nuclear club nations have been storing, containing and handling nuclear materials. By contrast, converting U-238 (which is the most common natural form of uranium) into Pu-239 can be accomplished with a low-tech breeder reactor (for a bizarre example of how low-tech fissionable materials projects can turn out, read the Tale of the Radioactive Boy Scout). Take away the concern for the health and well-being of the technicians, and a lot of radiological problems go away.

Thus it all comes down to keeping the goods out of the wrong hands. If our effort is at all as effective as the War on Drugs has been, duck and cover.

Imal

[secretagent]

Or if you don't care about this life, you could just slap the two sub-critical masses together with your hands, I guess.

A different kind of thunderclap.