Here is the original article
http://arxiv.org/pdf/0808.3283v1
Here is a follow-on article looking for any variations in decay rates
of Pu 238.
http://arxiv.org/pdf/0809.4248v1
"Data from the power output of the radioisotope thermoelectric
generators aboard the Cassini spacecraft are used to test the
conjecture that small deviations observed in terrestrial measurements
of the exponential radioactive decay law are correlated with the
Earth-Sun distance. No significant deviations from exponential decay
are observed over a range of 0.7 - 1.6 A.U. A 90% Cl upper limit of
0.84 x 10^-4 is set on a term in the decay rate of Pu-238
proportional to 1/R^2 and 0.99 x 10^-4 for a term proportional to 1/R."
It may not be distance that is the primary factor. It certainly is
known that various factors affect decay rates. For example, here are
some whopping statements from:
http://www.newscientist.com/article/mg20327190.100-nuclear-decay-
puzzle.html
"... a previous New Scientist article (21 October 2006, p 36) ..."
reported "they could modify the radioactive decay of certain
radioisotopes by encasing them in metal and chilling them close to
absolute zero." "... (11 November 2006, p 26)..." , Otto
Reifenschweiler "found that the radioactive decay of tritium absorbed
in titanium particles could be reduced by 40 per cent at temperatures
between 115 °C and 275 °C (Physics Letters A, vol 184, p 149)". "The
most dramatic change in radioactive decay has, however, recently been
observed by Fabio Cardone and others on the decay of thorium-228 by
using ultrasonic cavitation in water (Physics Letters A, vol 373, p
1956). In this case, the radioactive decay rate was increased by a
whopping factor of 10,000."
Here is an antineutrino theory:
http://www.mindandmuscle.net/forum/index.php?showtopic=38667
"Nuclei such as silicon-32 undergo beta decay, during which a neutron
in the atomic nucleus decays into the slightly less massive proton.
As it does so, it emits an electron and a near-massless particle, an
antineutrino. As antineutrinos are notoriously difficult to detect,
beta decay is signalled simply by a nucleus spontaneously emitting an
electron."
"Fischbach and Jenkins suggest that another reaction would, in
theory, have the same signature. If a neutrino - a sister particle to
the antineutrino - knocked into a neutron in an atomic nucleus, it
would produce a proton and an electron. The nuclear fusion reactions
that power the sun's core are spewing neutrinos equally in all
directions. The further away from that source you go, the more spread
out those neutrinos are. The higher flux of neutrinos through the
Earth when it is close to the sun would therefore bump up nuclear
decay rates"
Other related URLs:
http://physicsworld.com/cws/article/news/36108
http://www.blog.thecastsite.com/?p=95
http://findarticles.com/p/articles/mi_m1200/is_11_174/ai_n31179075/
http://www.sciencenews.org/view/feature/id/38341/title/Half-life_
(more_or_less)
http://maurol.com.ar/decay_rates/velocity_distance.png
Best regards,
Horace Heffner
http://www.mtaonline.net/~hheffner/
