RE: Decay properties change at temperature extremes?

["Boyce, Dale" <DBoyce@intiso.com>]

I don't think it works that way a BEC of neutrons would still be made up of
neutrons more massive than a proton added to the BEC.  The decay enegetics
should still prevail.  I see where you are coming from in that a neutron
star is also a Fermi gas, but in that case gravity has worked to make a
proton electron combination more massive than the neutron.

Dale
dboyce@intiso.com

> -----Original Message-----
> From:	Franta, Jaroslav [SMTP:frantaj@aecl.ca]
> Sent:	Monday, November 15, 1999 1:12 PM
> To:	Multiple recipients of list
> Subject:	RE: Decay properties change at temperature extremes?
> 
> 
> Radsafe colleagues,
> 
> I'm not sure whether this strays too much from permitted RADSAFE topics,
> but
> your question is one that's been puzzling me a little as well --
> especially
> since last year's announcement of the famous experiment of super-cold Bose
> Einstein Condensation (BEC) of atoms, using laser trapping & cooling. 
> The experiment involved neutral atoms (magnetic traps do work for neutral
> particles - the field
> interacts not with the charge but with the magnetic dipole moment), so it
> should, in theory be possible to condense a bunch of neutrons also (the
> laser frequency would probably have to different ??).
> The point is that "free" neutrons have a half-life of ~ 12 minutes,
> whereas
> neutrons inside (stable) atomic nuclei and in neutron stars are stable (or
> extremely long-lived). So, one would expect that a BEC made of neutrons
> would behave like an atomic nucleus or a piece of neutron-star-stuff  --
> with unlimited life span. Wonder whether the transition would be sudden,
> or
> whether there would be a gradual increase in life as the BEC state (the
> neutron wavefunctions will start to interact with each other) is
> approached
> ? Presumably, a BEC made of atoms with radioactive nuclei would also
> result
> in lifetime increases (?) - and would be easier to do experimentally than
> the pure neutron version... maybe someone's even tried to do this already
> ?
> 
> Jaro
> frantaj@aecl.ca
> > ----------
> > From: 	Langenegger, Armin[SMTP:alang@allsaintshealthcare.org]
> > Reply To: 	radsafe@romulus.ehs.uiuc.edu
> > Sent: 	Monday, November 15, 1999 11:56 AM
> > To: 	Multiple recipients of list
> > Subject: 	RE: Decay properties change at temperature extremes?
> > 
> > Hello Bob,
> > 
> > There was a physics today article a few years back that showed
> > polarization
> > of beta decay at ultra low temps, that is the directions of the ejected
> > beta
> > was in preferential directions as I recall.
> > 
> > Try going to the www.aip.org <http://www.aip.org>  web site and
> searching
> > the archives of physics today for the article.
> > 
> > Armin Langenegger MS DABMP
> > 
> > 
> > 		-----Original Message-----
> > 		From:	Zoon, Robert (OD) [mailto:razoon@exchange.nih.gov]
> > 		Sent:	Monday, November 15, 1999 9:53 AM
> > 		To:	Multiple recipients of list
> > 		Subject:	Decay properties change at temperature
> > extremes?
> > 
> > 		Dear Radsafer's:
> > 
> > 		One of our scientists has posed the question below and I
> > said that, although I
> > 		believe the answer is no from everything I have been taught
> > about radioactive
> > 		decay, I would try to see if any research has been done in
> > this area:
> > 
> > 		The question is:  Is there any change in the decay
> > properties of alpha or beta
> > 		emitters at extremes of temperature, either high or low?
> > His specific range of
> > 		interest was 0 - 500 degrees Kelvin.  I wouldn't expect any
> > change at 500 K,
> > 		which is only about 227 degrees C.  However, a lot of
> > strange things happen as
> > 		materials approach absolute zero.
> > 
> > 		Any help would be greatly appreciated, even a contact at a
> > university or
> > 		research laboratory.
> > 
> > 		Bob Zoon
> > 		Radiation Safety Officer, NIH
> > 		301-496-2254
> > 
> > 	
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