Startling amounts of stored energy in fully ionized plasmas.

On Oct 28, 6:09 pm, Robert Clark wrote:
...
The problem with the storage of these ions at high density is that
you have to overcome the large electrostatic repulsion between them
when they are close together.
Then what might work would be methods of screening out the electric
field between the ions. I asked about methods of accomplishing this
he

Newsgroups: sci.physics, sci.physics.relativity
From:
Date: 7 Jul 2005 10:42:54 -0700
Local: Thurs, Jul 7 2005 1:42 pm
Subject: Expelling an electric field.http://groups.google.com/group/sci.p...d/thread/aff52...

One suggested solution was the Faraday Cage:

Faraday cage.http://en.wikipedia.org/wiki/Faraday_cage

I had thought that the Faraday cage wouldn't prevent the electric
field from escaping but as described in the wikipedia page if the cage
is grounded then effectively the charge and the field inside would be
contained. Would the ground though eventually drain off the charge
inside?
If this works we could have a highly conducting metal, ideally a
"perfect" conductor, surrounding a group of charges thus reducing the
electrostatic repulsion that had to be restrained. We would have to
have a ground wire connected to each cage around the group of
charges.
Since we want high density each metal cage would have to be
nanoscopically thin. Is there a limit to how well the cage can work
dependent on its thickness? We would also have to have a method of
accessing the ions to be able to extract the electron recombinationenergyin the case of ion storage or the matter-antimatter conversionenergyin the case of positron storage.

Bob Clark

Hmm. An interesting question: would you have to have the electric
fields prevented from exiting the Faraday cages? Would simply having
the electric fields from the charges being prevented from entering the
cages of the other charges be sufficient? In that case you wouldn't
need to have the cages be grounded.
Another question: could you have the cages contacting each other to
save even more space? In this case it would be like having a 3-
dimensional metal lattice of hollow little cubes with a charge or
group of charges inside each cube.

Bob Clark

I found this report that fullerenes can act as Faraday cages at the
nanoscale:

C60 as a Faraday cage.
Appl. Phys. Lett. -- January 19, 2004 -- Volume 84, Issue 3, pp.
431-433.
"Endohedral fullerenes have been proposed for a number of
technological uses, for example, as a nanoscale switch, memory bit and
as qubits for quantum computation. For these technology applications,
it is important to know the ease with which the endohedral atom can be
manipulated using an applied electric field. We find that the
Buckminsterfullerene (C60) acts effectively as a small Faraday cage,
with only 25% of the field penetrating the interior of the molecule.
Thus influencing the atom is difficult, but as a qubit the endohedral
atom should be well shielded from environmental electrical noise. We
also predict how the field penetration should increase with the
fullerene radius."
http://titus.phy.qub.ac.uk/group/Pau...2004_43 1.pdf

This discusses though that the electric field is screened down only
to 25% of its external value. This is probably because carbon is not
normally the best of conductors. If a similar nanoscale cage could be
produced of better conducting metals it should result in near 100%
screening.
This also quite likely would work with carbon nanotubes formed into
cylindrical cages since the nanotubes can be formed with end caps. It
is known that nanotubes can be conducting or semiconducting according
to the orientation of the carbon atoms:

Carbon nanotube.
"Electrical
Because of the symmetry and unique electronic structure of graphene,
the structure of a nanotube strongly affects its electrical
properties. For a given (n,m) nanotube, if n - m is a multiple of 3,
then the nanotube is metallic, otherwise the nanotube is a
semiconductor. Thus all armchair (n=m) nanotubes are metallic, and
nanotubes (5,0), (6,4), (9,1), etc. are semiconducting. In theory,
metallic nanotubes can have an electrical current density more than
1,000 times greater than metals such as silver and copper."
http://en.wikipedia.org/wiki/Carbon_nanotube#Electrical

How metallic are metal nanotubes?
By Kimberly Patch, Technology Research News
May 30, 2001
http://www.trnmag.com/Stories/053001...es_053001.html

Another possibility comes from the fact that the spherical fullerenes
can come in nested form:

CARBON ONIONS.
Number 101 (Story #1), October 30, 1992
http://www.aip.org/pnu/1992/split/pnu101-1.htm

Bonding Bucky-Onions.
13 November 2001
http://focus.aps.org/story/v8/st27

The fullerene "onions" can come in up to 70 shells.

Then if a single shell fullerene reduces the electric field inside by
1/4, five layers should reduce it by a factor of about 1/1,000 and ten
layers by about 1/1,000,000.



Bob Clark

On Oct 12, 3:56 am, Craig Markwardt
wrote:
This is not really a good method for storing energy. The losses are
too rapid.

In order to maintain (say) Xenon in a fully ionized state, a Boltzmann
equilibrium must be achieved. Removing the last two electrons of
Xenon takes ~40 keV each (ref. X-ray Data Book, xdb.lbl.gov). Thus,
the temperature must be (kB T 40 keV) where kB is the Boltzmann
constant. Let's say kB T = 100 keV, or a temperature of 1 billion Kelvins.
That is hot.

Your assumption is flawful. Screw Boltzmann equilibrium: Do you
discount the storing of a bomb by the equilibrial states of its decay
products? Hydrogen plasma is permanent in interstellar vacua, yet
they're too cold to ionize ground-state hydrogen.

The Bremsstrahlung emissivity of a plasma scales approximately as,
W = 1.4e-34 ne nZ Z^2 T^(0.5) in Joule / s / cm^3
where ne is the electron density, nZ is the ion density, Z
is the atomic number of the ion. (ne and nZ must be in cm^{-3}).
Compare this to your quoted energy density of (200 keV / ion)
= (3.2e-14 Joules / ion), or an energy density of E = 3.2e-14 nZ Joules / cm^3.

No, emissivity scales with a ~, not a =, and hangs on emissanse, which
can lie between 0 and 1.

Even your "low" density of 4e14 ions/cm^3, the ratio of W / E
is 1/(0.11 msec). In other words, all the internal (and ionization)
energy of the plasma will leak out in less than 1 millisecond by
bremsstrahlung radiation. This is radiation that can't be contained
by any magnetic field or trap, so it is unavoidable.

Not to mention the danger of carrying around a tank of 1 billion
degree plasma...

A lightning bolt cannot be contained, yet its charges obviosely can
and are. You suck.

-Aut

On Nov 20, 11:19 pm, Robert Clark wrote:
This discusses though that the electric field is screened down only
to 25% of its external value. This is probably because carbon is not
normally the best of conductors. If a similar nanoscale cage could be
produced of better conducting metals it should result in near 100%
screening.
This also quite likely would work with carbon nanotubes formed into
cylindrical cages since the nanotubes can be formed with end caps. It
is known that nanotubes can be conducting or semiconducting according
to the orientation of the carbon atoms:

3D chain-links of nanotubular rings: start with cubes, then go for
Borromean tetrahedra

The fullerene "onions" can come in up to 70 shells.

Then if a single shell fullerene reduces the electric field inside by
1/4, five layers should reduce it by a factor of about 1/1,000 and ten
layers by about 1/1,000,000.

Shielding drops off with size, remember?

On Nov 21, 8:58 pm, "Autymn D. C." wrote:
On Nov 20, 11:19 pm, Robert Clark wrote:

This discusses though that the electric field is screened down only
to 25% of its external value. This is probably because carbon is not
normally the best of conductors. If a similar nanoscale cage could be
produced of better conducting metals it should result in near 100%
screening.
This also quite likely would work with carbon nanotubes formed into
cylindrical cages since the nanotubes can be formed with end caps. It
is known that nanotubes can be conducting or semiconducting according
to the orientation of the carbon atoms:

3D chain-links of nanotubular rings: start with cubes, then go for
Borromean tetrahedra

The fullerene "onions" can come in up to 70 shells.

Then if a single shell fullerene reduces the electric field inside by
1/4, five layers should reduce it by a factor of about 1/1,000 and ten
layers by about 1/1,000,000.

Shielding drops off with size, remember?

Yes the paper I referred to does mention they *calculated* the
shielding should become worse with large size buckyballs:

C60 as a Faraday cage.
Appl. Phys. Lett. -- January 19, 2004 -- Volume 84, Issue 3, pp.
431-433.
"Endohedral fullerenes have been proposed for a number of
technological uses, for example, as a nanoscale switch, memory bit and
as qubits for quantum computation. For these technology applications,
it is important to know the ease with which the endohedral atom can be
manipulated using an applied electric field. We find that the
Buckminsterfullerene (C60) acts effectively as a small Faraday cage,
with only 25% of the field penetrating the interior of the molecule.
Thus influencing the atom is difficult, but as a qubit the endohedral
atom should be well shielded from environmental electrical noise. We
also predict how the field penetration should increase with the
fullerene radius."
http://titus.phy.qub.ac.uk/group/Pau...2004_43 1.pdf

This might be because carbon is not normally a good conductor, much
less the "perfect conductor" required for the Faraday cage do to
complete screening.
Ideally, though a Faraday cage does complete screening regardless of
the size.
BTW, here's a nice animation of how the electric field lines bend
around a conducting cage:

Isolated Cylinder
http://socrates.berkeley.edu/~fajans...iles/frame.htm

The applet showing this for some reason does not show up on my
computer using the Firefox browser, but shows up well using IE.
How well the nested buckyballs could do screening would have to be
determined by experiment. Also, carbon can become superconducting at
very low temperatures.
I mentioned that you would get better screening using metal
buckyballs. I don't know if this has been done but I found a report
showing that it should be possible with boron (also not a metal):

Bucky's brother -- The boron buckyball makes its debut.
Published: 12:29 EST, April 23, 2007
http://www.physorg.com/news96550194.html

Another consideration for space based applications is the mass of the
cage compared with the mass of the charged particle it contained. If
the particle was uranium, with an atomic mass of 238, contained in a
single layer carbon fullerene C60, the ratio of the container to the
ions would be 60x12 = 720 to 238, or 3 to 1.
Ideal would be a light metal that could be formed into a single
atomic layer cage. Lithium for example is classified as an alkali
metal with a conductivity more than 100 times that of carbon:

Lithium.
http://www.chemicool.com/elements/lithium.html

Carbon.
http://www.chemicool.com/elements/carbon.html


Bob Clark

On Nov 22, 10:47 am, Robert Clark wrote:
On Nov 21, 8:58 pm, "Autymn D. C." wrote:

...
The fullerene "onions" can come in up to 70 shells.
Then if a single shell fullerene reduces the electric field inside by
1/4, five layers should reduce it by a factor of about 1/1,000 and ten
layers by about 1/1,000,000.

Shielding drops off with size, remember?

Yes the paper I referred to does mention they *calculated* the
shielding should become worse with large size buckyballs:

C60 as a Faraday cage.
Appl. Phys. Lett. -- January 19, 2004 -- Volume 84, Issue 3, pp.
431-433.
"Endohedral fullerenes have been proposed for a number of
technological uses, for example, as a nanoscale switch, memory bit and
as qubits for quantum computation. For these technology applications,
it is important to know the ease with which the endohedral atom can be
manipulated using an applied electric field. We find that the
Buckminsterfullerene (C60) acts effectively as a small Faraday cage,
with only 25% of the field penetrating the interior of the molecule.
Thus influencing the atom is difficult, but as a qubit the endohedral
atom should be well shielded from environmental electrical noise. We
also predict how the field penetration should increase with the
fullerene radius."http://titus.phy.qub.ac.uk/group/Paul/publications/2004/Delaney_Greer...

This might be because carbon is not normally a good conductor, much
less the "perfect conductor" required for the Faraday cage do to
complete screening.
Ideally, though a Faraday cage does complete screening regardless of
the size.
BTW, here's a nice animation of how the electric field lines bend
around a conducting cage:

Isolated Cylinderhttp://socrates.berkeley.edu/~fajans/Teaching/cartoons/Shielding/Test...

The applet showing this for some reason does not show up on my
computer using the Firefox browser, but shows up well using IE.
How well the nested buckyballs could do screening would have to be
determined by experiment. Also, carbon can become superconducting at
very low temperatures.
I mentioned that you would get better screening using metal
buckyballs. I don't know if this has been done but I found a report
showing that it should be possible with boron (also not a metal):

Bucky's brother -- The boron buckyball makes its debut.
Published: 12:29 EST, April 23, 2007http://www.physorg.com/news96550194.html

Another consideration for space based applications is the mass of the
cage compared with the mass of the charged particle it contained. If
the particle was uranium, with an atomic mass of 238, contained in a
single layer carbon fullerene C60, the ratio of the container to the
ions would be 60x12 = 720 to 238, or 3 to 1.
Ideal would be a light metal that could be formed into a single
atomic layer cage. Lithium for example is classified as an alkali
metal with a conductivity more than 100 times that of carbon:

Lithium.http://www.chemicool.com/elements/lithium.html

Carbon.http://www.chemicool.com/elements/carbon.html

Bob Clark

Just did a web search and found "buckyballs" have been made of gold,
which of course is an excellent conductor:

Buckyballs Make Room For Gilded Cages.
ScienceDaily (May 16, 2006) -- "Scientists have uncovered a class of
gold atom clusters that are the first known metallic hollow
equivalents of the famous hollow carbon fullerenes known as
buckyballs."
....
"The fullerene is made up of a sphere of 60 carbon (C) atoms; gold
(Au) requires many fewer--16, 17 and 18 atoms, in triangular
configurations more gem-like than soccer ball. At more than 6
angstroms across, or roughly a ten-millionth the size of this comma,
they are nonetheless roomy enough to cage a smaller atom."
http://www.sciencedaily.com/releases...0516075733.htm

Gold though is quite heavy at an atomic weight of nearly 200. So even
with the gold cage containing 16 atoms it still would be heavier than
the C60 cage. Still it would be interesting to find out how good the
gold cages are at screening electric charge.


Bob Clark

On Nov 22, 10:47 am, Robert Clark wrote:
On Nov 21, 8:58 pm, "Autymn D. C." wrote:



On Nov 20, 11:19 pm, Robert Clark wrote:

This discusses though that the electric field is screened down only
to 25% of its external value. This is probably because carbon is not
normally the best of conductors. If a similar nanoscalecagecould be
produced of better conducting metals it should result in near 100%
screening.
This also quite likely would work with carbon nanotubes formed into
cylindrical cages since the nanotubes can be formed with end caps. It
is known that nanotubes can be conducting or semiconducting according
to the orientation of the carbon atoms:

3D chain-links of nanotubular rings: start with cubes, then go for
Borromean tetrahedra

The fullerene "onions" can come in up to 70 shells.

Then if a single shell fullerene reduces the electric field inside by
1/4, five layers should reduce it by a factor of about 1/1,000 and ten
layers by about 1/1,000,000.

Shielding drops off with size, remember?

Yes the paper I referred to does mention they *calculated* the
shielding should become worse with large size buckyballs:

C60 as aFaradaycage.
Appl. Phys. Lett. -- January 19, 2004 -- Volume 84, Issue 3, pp.
431-433.
"Endohedral fullerenes have been proposed for a number of
technological uses, for example, as a nanoscale switch, memory bit and
as qubits for quantum computation. For these technology applications,
it is important to know the ease with which the endohedral atom can be
manipulated using an applied electric field. We find that the
Buckminsterfullerene (C60) acts effectively as a smallFaradaycage,
with only 25% of the field penetrating the interior of the molecule.
Thus influencing the atom is difficult, but as a qubit the endohedral
atom should be well shielded from environmental electrical noise. We
also predict how the field penetration should increase with the
fullerene radius."http://titus.phy.qub.ac.uk/group/Paul/publications/2004/Delaney_Greer...

This might be because carbon is not normally a good conductor, much
less the "perfect conductor" required for theFaradaycagedo to
complete screening.
Ideally, though aFaradaycagedoes complete screening regardless of
the size.
BTW, here's a nice animation of how the electric field lines bend
around a conductingcage:

Isolated Cylinderhttp://socrates.berkeley.edu/~fajans/Teaching/cartoons/Shielding/Test...

The applet showing this for some reason does not show up on my
computer using the Firefox browser, but shows up well using IE.
How well the nested buckyballs could do screening would have to be
determined by experiment. Also, carbon can become superconducting at
very low temperatures.
I mentioned that you would get better screening using metal
buckyballs. I don't know if this has been done but I found a report
showing that it should be possible with boron (also not a metal):

Bucky's brother -- The boron buckyball makes its debut.
Published: 12:29 EST, April 23, 2007http://www.physorg.com/news96550194.html

Another consideration for space based applications is the mass of thecagecompared with the mass of the charged particle it contained. If
the particle was uranium, with an atomic mass of 238, contained in a
single layer carbon fullerene C60, the ratio of the container to the
ions would be 60x12 = 720 to 238, or 3 to 1.
Ideal would be a light metal that could be formed into a single
atomic layercage. Lithium for example is classified as an alkali
metal with a conductivity more than 100 times that of carbon:

Lithium.http://www.chemicool.com/elements/lithium.html

Carbon.http://www.chemicool.com/elements/carbon.html

Bob Clark

Notably boron becomes a superconductor at ever increasing
temperatures according to pressure at the megabar pressure range:

Newsgroups: sci.materials, sci.astro, sci.physics, sci.energy,
sci.chem
From: Robert Clark
Date: Thu, 22 Nov 2007 15:29:03 -0800 (PST)
Local: Thurs, Nov 22 2007 6:29 pm
Subject: A route to room-temperature superconductivity?
http://groups.google.com/group/sci.m...6b68f22afdc0c/


Bob Clark

Thanks for the interesting topic. Endofullerene is quite an exotic molecule and you have a lot of room to fiddle with it. In this context it really looks promising. Iam really excited about fast development of these materials.. For example check this one out: http://mstnano.com/products/endofullerene/