Path: utzoo!attcan!uunet!know!zaphod.mps.ohio-state.edu!usc!ucsd!pacbell.com!att!cbnews!cbnews!military From: ntaib@silver.ucs.indiana.edu (Nur Iskandar Taib) Newsgroups: sci.military Subject: Re: Question about Nuclear Weapons Keywords: MRVs Message-ID: <1990Oct25.151832.2153@cbnews.att.com> Date: 25 Oct 90 15:18:32 GMT References: <1990Oct23.190943.7623@cbnews.att.com> <1990Oct24.114913.4072@cbnews.att.com> Sender: military@cbnews.att.com (William B. Thacker) Organization: Indiana University, Bloomington IN. Lines: 40 Approved: military@att.att.com From: ntaib@silver.ucs.indiana.edu (Nur Iskandar Taib) >>My question >>is as follows: Are not nuclear weapons detinated buy compressing the core of >>highly radioactive material until the mass is critical? If so couldn't (at >>least theoretically) the pressure of the water on the warhead at deep depths >>cause the warhead to ge critical? I always thought the fissionable material is stored in the bomb in several sub-critical mass pieces, which are slammed together by explosive charges. I wonder if the explosives are really necessary: if one simply moves all the pieces together into a big lump (do neutrons really care if there is 0.1mm of air in the way?) won't it ex- ceed critical mass and go off? I heard that the first atomic bomb scientists determined the critical mass for ^235 U by dropping various size spheres through donuts, and watching for neutrons. This was supposedly very risky.. if the two together exceeded critical mass, the whole thing could have gone off. Now, whether or not deep sea pressures are enough to squeeze the pieces of Pu together depends on many things: 1) How strong is the case 2) does it leak 3) will the pieces fit together even if forced together, or are they made so that they do not interlock, and one would need high explosive to force it into a spherical shape? If the case is too strong, the pressures will not crush it. If it leaks, the pressure inside will be the same as outside, so the pieces stay stationary. If the pieces don't fit together, it may end up with a big empty space in the middle. I don't think pressures even six miles down match what is produced by the triggering high explosives in the bomb. ------------------------------------------------------------------------------- Iskandar Taib | The only thing worse than Peach ala Internet: NTAIB@AQUA.UCS.INDIANA.EDU | Frog is Frog ala Peach Bitnet: NTAIB@IUBACS !