Spasers for Solar Energy Intensification?
EdV
development of a material that would soak up solar energy without
focusing mirrors for some period of time . . . all day for instance.
The material would be "pumped up" so to speak. It could then be
"spas'd"(surface plasmon amplification by stimulated emission'd) to
release stored energy at a higher rate than it was pumped.
Can anyone direct me to an easy introduction to plasmons? I mean like
a "Beyond the Mechanical Universe" type of treatment. I had no idea
they were bosons until yesterday. I am sure there all sorts of
efficiency losses that would make this sort of optical battery/
capacitor impracticable but it looked like a fun thought experiment to
get me looking at bosons again. I need to do something besides take
walks and play the piano during my lay off.
Best,
Ed Vogel
Uncle Al
>
> I have often wondered if nano technology
warning strobe
> might allow for the
> development of a material that would soak up solar energy without
> focusing mirrors for some period of time . . . all day for instance.
> The material would be "pumped up" so to speak. It could then be
> "spas'd"(surface plasmon amplification by stimulated emission'd) to
> release stored energy at a higher rate than it was pumped.
Cu-, Ag-, and Mn-doped ZnS latch from visible radiation. You can
diddle quantum well depth to slowly decay phosphorescence, or go deep
and wait until triggered by IR input. Storing 12 hrs of average 1.37
kW/m^2 as stable solid state excitation is silly. That is why we have
batteries.
Focus is wholly unnecessary. Take three fluorescent dyes in toto
absorbing across the solar spectrum, wrap each around a suitable
lanthanide ion plus a couple more ligands to a coordination number
around 10, preferably as an anion. Blue, yellow, red light goes into
the dye, near-IR is emitted from the ion at silicon's absorption
maximum. Metal-ballasted dyes don't fade. Cast a dye-doped sheet of
Plexiglas. Commercial Plexiglas is supplied 72"x96"x3/8". One-side
face area is 6912 in^2. Total edge area is 63 in^2. It is a 110X
solar concentrator via total internal reflection. Works fine on
cloudy days for it is not imaging.
Total internal reflection loses fluorescence inside the cone angle.
One therefore desires a clear plastic with higher refractive index and
a narrower loss cone.
critical
RI angle Stuff
================================
1.4896 42.2 poly(methyl methacrylate)
1.591 38.9 poly(styrene)
1.633 37.8 polysulfone
1.71 35.8 poly(pentabromophenyl)methacrylate
2.022 29.6 LASF35 top and bottom plates
(29.6/42.2)^2 = 49% the cone loss for a sandwich: doped Plexiglas
core; top anti-reflection coated LASF35 coverslip, bottom LASF35
coverslip; both optically bonded. No "nano" hornswoggle.
> Can anyone direct me to an easy introduction to plasmons? I mean like
> a "Beyond the Mechanical Universe" type of treatment. I had no idea
> they were bosons until yesterday. I am sure there all sorts of
> efficiency losses that would make this sort of optical battery/
> capacitor impracticable but it looked like a fun thought experiment to
> get me looking at bosons again. I need to do something besides take
> walks and play the piano during my lay off.
KISS = Keep It Simple, etc.
--
Uncle Al
http://www.mazepath.com/uncleal/
(Toxic URL! Unsafe for children and most mammals)
http://www.mazepath.com/uncleal/qz4.htm
X-Phy
> I have often wondered if nano technology might allow for the
> development of a material that would soak up solar energy without
> focusing mirrors for some period of time . . . all day for instance.
> The material would be "pumped up" so to speak. It could then be
> "spas'd"(surface plasmon amplification by stimulated emission'd) to
> release stored energy at a higher rate than it was pumped.
Do you mean a plasmon laser? You'll need sort of a resoning cavity,
so an efficent way to reflect plasmon. Have you in mind a specific
technology to do that? I know none.
> Can anyone direct me to an easy introduction to plasmons? I mean like
> a "Beyond the Mechanical Universe" type of treatment. I had no idea
> they were bosons until yesterday.
Bosons are very common, indeed every quanta of a mechanical
oscillation is one, like phonons.
A plasmon is very similar to a phonon. It take place in a plasma,
that is a highly ionized gaz. Thus there are too types of free charged
particles: electrons and positive ions. In first approximation, as
they are much heavier, we can consider the ion fixed. Then, if the
electrons are collectively displaced, a difference of charge appears
that tends to put them back in place, which is an equilibium
position. So there is a force opposit to the displacement, and
therefore an oscillator. A plasmon is the quantum of the
corresponding oscillation, approximated near the equilibrium position
to an harmonic oscillation (the force is proportional to the
displacement, the potential is a parabola, the oscillation is a sine/
cosine function of time.)
As it is a continuous medium, this description must be made at each
point, and in fact the variables to considere are the electron (or
charge) density and the electron flux (or electric current,) under the
constraint that the total charge is conserved. Thus, a wave propagates
in a medium that is described as a collection of coupled harmonic
oscillator at each point. The plasmon is the quantization of this
wave, and in addition to an oscillation at one point, there are many
other modes, among which a propagating plasmon, just like a phonon in
an acoustical wave (sound.)
I don't well know an easy introduction, but I think there is a sketch
in the Berkeley lecture on physics about waves. Anyway that book is a
very good introduction to waves
Dirk Bruere at NeoPax
I doubt that it would work for more than a few milliseconds, given the
energy densities involved.
However, there is a fictional treatment of such a material "slow glass":
http://en.wikipedia.org/wiki/Slow_light
--
Dirk
http://www.transcendence.me.uk/ - Transcendence UK
http://www.theconsensus.org/ - A UK political party
http://www.blogtalkradio.com/onetribe - Occult Talk Show