Naked Science Forum

Non Life Sciences => Physics, Astronomy & Cosmology => Topic started by: Atomic-S on 19/12/2009 02:28:51

Title: Can the rate of nuclear decay be controlled by selection?
Post by: Atomic-S on 19/12/2009 02:28:51

If some way could be found to sort those atomic nuclei of a particular isotope that were

about to decay, from those that would not decay until later, one could control the half

life of a sample, a result  that would have many uses. That this might be possible, is

suggested by the fact that we can sort, from a sample of certain atoms that have equal

probability of being found spin up or spin down,those that are "up" vs. those that are

"down", and this sorting remains valid for some time afterward. As to sorting nuclei

according to the likelihood that they will decay soon, the key is to find a process to

do it. One scheme that comes to mind is to exploit the fact that certain nuclei emit

more beta particles toward one rather than the other magnetic pole. This would suggest

sorting them magnetically. However, this actually will not help because this procedure

will determine only what will be the probable direction in which the resultant sample

will decay, not its rate.

Another idea: Inasmuch as E=mc^2, each particle oscillates at a quantum frequency that

is proportinal to its mass-energy. But this invokes the energy-time uncertainty

relationship, which states that if the state of a system exists for a finite length of

time, then the energy of that state cannot be established more precisely than about

h/(delta T). Pursuant to Einstein, neither can its mass be precisely established. The

trick is, then, to exploit the fact that a nucleus that will decay soon has a less

definite mass than one that will decay later. Let be measured the masses very, very

precisely, setting up the process to weed out nuclei whose exact mass differs

significantly from the mean. The leftover nuclei would have a higher chance of lasting

longer than average.

Any other ideas?

Title: Can the rate of nuclear decay be controlled by selection?
Post by: Soul Surfer on 19/12/2009 20:48:04

I do not think that it is possible to do the sorting process that you suggest it is similar to asking someone to sort the faster moving gas molecules from the slower ones in a particular sample of gas you require a Maxwell's demon  (QV  google) this is clearly shown to result in no advantage because the cost of doing the sorting precisely nullifies the benefits from the sort.  It is also worse than this because it is not possible (because of Heisenberg's uncertainty principle)to identify which of the atoms are most likely to decay or when they will.

Title: Can the rate of nuclear decay be controlled by selection?
Post by: Pmb on 20/12/2009 02:29:13

Quote from: Atomic-S on 19/12/2009 02:28:51

If some way could be found to sort those atomic nuclei of a particular isotope that were about to decay, from those that would not decay until later, one could control the half life of a sample, a result  that would have many uses.

Such a think is impossible according to modern quantum theory. No two isotopes have anything which distinguish one from the other and as such inentical in every concievble way. Thus each as the same probability of disintegrating in any given time interval. However when each actually does disintegrate cannot be determined in anyway what soever.

Title: Can the rate of nuclear decay be controlled by selection?
Post by: Farsight on 20/12/2009 16:34:05

Atomic-S: I don't think you can sort nuclei like this. There is however another way to achieve what you're maybe looking for. See http://www2.hud.ac.uk/sas/comment/bc080709.php. Professor Bob Cywinski at Huddersfield University is working on controlled thorium fission:

"The additional neutrons needed to drive the fission process and generate energy are produced by bombarding a metal target within the reactor with high energy particles from a particle accelerator. Some of the electrical energy produced by the reactor (say 5%) is used to drive the accelerator. If the accelerator is switched off, like a light bulb, no further neutrons are produced and the reactor also switches off".

Title: Can the rate of nuclear decay be controlled by selection?
Post by: syhprum on 22/12/2009 23:08:03

There is some evidence that radioactive decay is mediated by Neutrino flux.

http://redshift.vif.com/JournalFiles/V08NO2PDF/V08N2FAL.pdf

Title: Can the rate of nuclear decay be controlled by selection?
Post by: Atomic-S on 13/05/2010 06:30:16

Quote

http://redshift.vif.com/JournalFiles/V08NO2PDF/V08N2FAL.pdf

That is very interesting, albeit preliminry. It seems to call for doing a more rigorous experiment.

Title: Can the rate of nuclear decay be controlled by selection?
Post by: Atomic-S on 13/05/2010 06:32:33

Quote

http://www2.hud.ac.uk/sas/comment/bc080709.php.

That is very interesting; this sounds like a technology that needs to be pursued. (Although it does not answer my actual question).