[meteorite-list] Earths core

From: mark ford <markf_at_meteoritecentral.com>
Date: Mon Aug 9 11:45:11 2004
Message-ID: <6CE3EEEFE92F4B4085B0E086B2941B31014591_at_s-southern01.s-southern.com>

Hi

I think the key is that fission is possible because it's not just the
one element involved, you would certainly have a lot of weird physics
going on!

(From D. F. Hollenbach et al)
 
 "At the pressures that prevail in the Earth's core, density is a
function almost exclusively of atomic mass and atomic number. Uranium,
thorium, and other actinides, being high-temperature precipitates and
the densest substances, by the action of gravity, would tend to
concentrate, possibly scavenged by other precipitates, ultimately
forming a fissionable, critical mass (4-6). The same mechanism for
concentrating the actinides (i.e., gravitational separation by density
at high pressure) should cause the lighter fission products to separate
from the heavier actinides, thus helping to maintain a
nuclear-reactor-critical configuration."

Mark



-----Original Message-----
From: mark ford
Sent: 09 August 2004 16:36
To: stan .; meteorite-list_at_meteoritecentral.com
Subject: RE: [meteorite-list] Earths core


Stan,

Looking around, several studies have shown that a self sustaining
fission reaction, is indeed possible in the core of a planet.

See:
 
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=58687


Mark




-----Original Message-----
From: stan . [mailto:laser_maniac_at_hotmail.com]
Sent: 09 August 2004 16:15
To: mark ford; meteorite-list_at_meteoritecentral.com
Subject: RE: [meteorite-list] Earths core


>Well, Half life can't change (otherwise the universe would be in a real

>mess) but who knows what effect very very high pressure, heat and
>gravitational force would have on a fission reaction, maybe at the
earths
>core, a nuclear reaction happens at an accelerated rate due to the much

>higher pressures (i.e the atoms are forced much closer together, and
there
>would be total neutron absorbtion) or maybe even hot fusion? This would

>result in the radioisotopes transmuting into Lead and Iron etc a lot
faster
>than they would under natural decay.


fusion isn to going to be possible in the earth's core- tempertures are
off
by several orders of magnitude..

fission reactions arent affected by high pressure, heat or gravity
(within
sensible limits). as the earth's core is under tremendous pressure it's
density is increased, so the criticle mass of uranium is correspondingly

lowered, making it easier for a blob of uranium to undergo a fission
chain
reaction. this sint going to 'transmute radioisotopse into lead and
iron'
any faster however, since the timespan of the radioactive decay chain is

unchanged.

also, if we were to find a hunk of a heavy (density wise) element iron
meteorite, remeber that it would ahve to come from the core of a body
large
enough to differentiate to a similar extent as the earth (per your
original
question). i dont know if there are any asteroids out there that sample
hundreds if not thousands of miles inside of what used to be a large
body.

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Received on Mon 09 Aug 2004 11:42:06 AM PDT