On Sat, 17 Nov 2001, Tim May wrote:
I'd guess that the "tall pipe" version is the most buildable of the basement nukes. (In a nutshell: a tall drainpipe, perhaps 40 feet tall. Set up in an apartment building, warehouse, etc. At the base the pipe is reinforced with copious amounts of concrete. The subcritical masses are at opposite ends of the pipe. The mass on top is piled on with several hundred pounds of ballast, to "tamp" the early critical mass action. To explode the bomb, drop the mass from the top of the pipe. The critical mass is briefly contained by the concrete collar around the pipe and the inertial mass above. Is it enough to produce a real chain reaction? Well, it's all relative. Still, not very efficient.)
I very much doubt terrorist would build an efficient bomb. Non of what we discussed is effcient. Your pipe idea is a very interesting example. But I think the point is made that harm can be done. Even if the mass does not go critical - it still means a few city blocks that will be inconvenienced from the resulting radiation. You pipe certainly would not go boom - but it would leave a mess of radioactivity in the area. regards joe -- The dot.GOD Registry, Limited http://www.dot-god.com/