[extropy-chat] Nuclear batteries for hand-helds

[Mike Lorrey]

For the same reason that terrorists don't try to do the same thing with
smoke detectors or tritium exit signs, both products which are widely
used and are found in most people's homes and workplaces....

--- Adrian Tymes <wingcat at pacbell.net> wrote:

> Ah, but even if these are easily shielded, how to
> prevent people from cracking open the batteries,
> removing the radioactive bits, and concentrating them
> into the warhead of a dirty nuclear bomb?
> 
> The members of this list know how ridiculous the
> chances of that are, and how minimal the threat would
> be.  But try selling that to the luddite public who
> would want to ban this.
> 
> --- Mike Lorrey <mlorrey at yahoo.com> wrote:
> 
> >
> http://www.spectrum.ieee.org/WEBONLY/publicfeature/sep04/0904nuc.html
> > 
> > "Nuclear batteries can pack in energy at densities
> > THOUSANDS OF TIMES
> > greater than those of lithium-ion batteries"
> > 
> >
>
http://www.spectrum.ieee.org/WEBONLY/publicfeature/sep04/0904nuct1.html
> > 
> > " For these batteries, which we call radioactive
> > piezoelectric
> > generators, the radioactive source is a
> > 4-square-millimeter thin film
> > of nickel-63 [see illustration, "Power From
> > Within"]. On top of it, we
> > cantilever a small rectangular piece of silicon, its
> > free end able to
> > move up and down. As the electrons fly from the
> > radioactive source,
> > they travel across the air gap and hit the
> > cantilever, charging it
> > negatively. The source, which is positively charged,
> > then attracts the
> > cantilever, bending it down.
> > 
> > A piece of piezoelectric material bonded to the top
> > of the silicon
> > cantilever bends along with it. The mechanical
> > stress of the bend
> > unbalances the charge distribution inside the
> > piezoelectric crystal
> > structure, producing a voltage in electrodes
> > attached to the top and
> > bottom of the crystal.
> > 
> > After a brief period—whose length depends on the
> > shape and material of
> > the cantilever and the initial size of the gap—the
> > cantilever comes
> > close enough to the source to discharge the
> > accumulated electrons by
> > direct contact. The discharge can also take place
> > through tunneling or
> > gas breakdown. At that moment, electrons flow back
> > to the source, and
> > the electrostatic attractive force vanishes. The
> > cantilever then
> > springs back and oscillates like a diving board
> > after a diver jumps,
> > and the recurring mechanical deformation of the
> > piezoelectric plate
> > produces a series of electric pulses.
> > 
> > The charge-discharge cycle of the cantilever repeats
> > continuously, and
> > the resulting electric pulses can be rectified and
> > smoothed to provide
> > direct-current electricity. Using this
> > cantilever-based power source,
> > we recently built a self-powered light sensor [see
> > photo, "It's Got the
> > Power"]. The device contains a simple processor
> > connected to a
> > photodiode that detects light variations. "
> > 
> > " For example, with 10 milligrams of polonium-210
> > (contained in about 1
> > cubic millimeter), a nuclear microbattery could
> > produce 50 milliwatts
> > of electric power for more than four months (the
> > half-life of
> > polonium-210 is 138 days). With that level of power,
> > it would be
> > possible to run a simple microprocessor and a
> > handful of sensors for
> > all those months.
> > 
> > And the conversion efficiency won't be stuck at 4
> > percent forever.
> > Beginning this past July we started working to boost
> > the efficiency to
> > 20 percent, as part of a new Defense Advanced
> > Research Projects Agency
> > program called Radio Isotope Micro-power Sources. "
> > 
> > =====
> > Mike Lorrey
> > Chairman, Free Town Land Development
> > "Necessity is the plea for every infringement of
> > human freedom.
> > It is the argument of tyrants; it is the creed of
> > slaves."
> >                                          -William
> > Pitt (1759-1806) 
> > Blog:
> > http://www.xanga.com/home.aspx?user=Sadomikeyism
> > 
> > 
> > 		
> > _______________________________
> > Do you Yahoo!?
> > Express yourself with Y! Messenger! Free. Download
> > now. 
> > http://messenger.yahoo.com
> > _______________________________________________
> > extropy-chat mailing list
> > extropy-chat at lists.extropy.org
> >
> http://lists.extropy.org/mailman/listinfo/extropy-chat
> > 
> 
> _______________________________________________
> extropy-chat mailing list
> extropy-chat at lists.extropy.org
> http://lists.extropy.org/mailman/listinfo/extropy-chat
> 


=====
Mike Lorrey
Chairman, Free Town Land Development
"Necessity is the plea for every infringement of human freedom.
It is the argument of tyrants; it is the creed of slaves."
                                         -William Pitt (1759-1806) 
Blog: http://www.xanga.com/home.aspx?user=Sadomikeyism


		
__________________________________
Do you Yahoo!?
Yahoo! Mail - 50x more storage than other providers!
http://promotions.yahoo.com/new_mail