Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.2 9/18/84; site utastro.UUCP Path: utzoo!linus!decvax!ucbvax!ucdavis!lll-crg!mordor!ut-sally!utastro!ethan From: ethan@utastro.UUCP (Ethan Vishniac) Newsgroups: net.physics Subject: Re: temperature & radioactive decay Message-ID: <68@utastro.UUCP> Date: Sat, 19-Oct-85 16:13:21 EDT Article-I.D.: utastro.68 Posted: Sat Oct 19 16:13:21 1985 Date-Received: Mon, 21-Oct-85 07:14:25 EDT References: <163@ccnysci.UUCP> Organization: U. Texas, Astronomy, Austin, TX Lines: 36 > >From: mikes@AMES-NAS.ARPA (Peter Mikes) > > > > I find it rather natural that temperature would not affect radioctivity > >- after all - if you imagine hotter material as bouncing atoms - then > > at any reasonable temperature only outer electron shells get deformed > > on each collision. There is no effect on the nucleus ( appart fom the > > broadening of lines due to the Doepler shift) and so no effect on the > > radioctivity. > > Sounds reasonable, but I have a question which relates to this: > Does the temperature of a plasma of radioactive atoms > have any effect on the radioactivity (half-life)? > (a plasma is at a temperature such that the electron shells are stripped > off - so in this case, 'collisions' disturb the nucleus) > (My guess is no - but I may be wrong) > > -GDS Atoms that decay by capturing an electron can be affected by their environment because anything that affects the electron orbitals can (theoretically) affect the capture rate. In practice you need to have such a strong environmental effect that the lowest energy level orbit is strongly perturbed, not an easy thing to do. The only way to affect other decays,i.e. beta or alpha emmission, is to reduce the phase space open to decay products. This would require a degenerate sea of electrons or alpha particles extending up to quite high levels. In practice I don't think this is achievable in a terrestrial environment. Neutron stars are made of neutrons that are stabilized in this way against beta decay. -- "Superior firepower is an Ethan Vishniac important asset when {charm,ut-sally,ut-ngp,noao}!utastro!ethan entering into ethan@astro.UTEXAS.EDU negotiations" Department of Astronomy University of Texas