On Mon, 2 Dec 2002, Bruce Moomaw wrote:
> On Dec 2, 2002, James McEnanly wrote: > > Is there a stable plutonium isotope? > > Nope -- the highest atomic-number element to have any stable isotopes is > bismuth (# 83). According to the Handbook of Chemistry and Physics, the most stable Pu isotopes appear to be: - Pu-242 with a half-life of ~3.8 x 10^5 years; and - Pu-244 with a half-life of ~8.7 x 10^7 years. The RTG's use Pu-238 with a half-life of 88 years. Weapons use Pu-239 with a half-life of 24,110 to 24,360 years (Google results vary). There are something like 16 isotopes. Webelements might list the lifetimes for more of them or you could probably ask Google as I think I've seen a table on the net. (Though the government may have taken or forced it to be taken down.) A very nice history of radioactive power in space satellites is "Nuclear Powered Space Missions - Past and Future" by Regina Hagen, located here: http://www.globenet.free-online.co.uk/ianus/npsmfp.htm Another good article seems to be "Nuclear Power in Space": http://www.nuc.umr.edu/nuclear_facts/spacepower/spacepower.html For an interesting, perhaps biased, discussion of the "Cassini Controversy" see: http://www.motherjones.com/news_wire/cassini.html A short essay on the radiation hazards of Pu is here: http://www.umich.edu/~radinfo/introduction/pluto.html It isn't clear to me whether it has been determined that all of the isotopes are superconducting. I would doubt it. Robert == You are subscribed to the Europa Icepick mailing list: [EMAIL PROTECTED] Project information and list (un)subscribe info: http://klx.com/europa/
