DON'T LOSE time and money around the fusion energy illusion and the lunar-helium-3 dream!!!

On Aug 29, 3:14 am, Ian Parker wrote:
The inherent problem with renewable power is that the Sun does not
always shine. The wind does not always blow. Sure they can make a
contribution.

Upon average, a 40 kw/m2 of a given tower surface footprint is in fact
somewhat limited, at roughly 100 fold better off than the all-
inclusive (aka honest birth to grave) nuclear alternative, and
otherwise totally nontoxic to boot. Go figure.
- Brad Guth

On Aug 29, 4:46 am, "Paul F. Dietz" wrote:
A: the #1 scientific rule states that all theories MUST be confirmed
by FACTS and REAL tests and measurements... until that REAL tests will
be accoplished (in the new moon missions from 2020) the lunar He3
still remanins just a THEORY
of course, the lunar regolith could have some "traces" of He3 and
other gases, but not "ONE MILLION" tons as claimed

Lunar 3He is a pretty safe extrapolation from the physical evidence returned
by the Apollo missions (and the soviet sample return). The exact quantity
needs to be better bounded, but this is more a matter of determining if
there
is even more at high latitudes (where diffusive escape from regolith grains
might be slowed at lower temperatures).

The big if is economic. Extracting 10 ppb 3He is very speculative. If you
need lunar infrastructure handling a sizeable fraction of the energy flow
you'd
get from the helium, just to extract it, the economics cannot make sense.

Paul

You are correct, except for that little NASA/Apollo silly thing about
samples returned, as actually being moon rock obtained from the
surface of Earth rather than directly from the moon itself. BTW,
lunar 3He would actually be a byproduct upon making atmosphere and
various basalt products.

However, do not forget about terrestrial 4He from natural gas. How
many thousand tonnes of 4He has been wasted thus far?
- Brad Guth

On Aug 29, 8:31 am, Ian Parker wrote:
As far as a return to the Moon is concerned. This seems much more
motivated by the dream of manned spaceflight and prestige rather than
on any attempt to extract He3. On any scientific or commercial basis
the wisdom of "back to the Moon" is extremely dubious anyway.

No kidding, to say the least it's "dubious" as all freaking get out,
and then some unless you've got rad-hard DNA plus banked bone marrow,
an actual working fly-by-rocket lander and a few spare tonnes worth of
dumb luck piled on top of all your lucky stars.
- Brad Guth

I have been thinking about this. I will agree that one should have an
open mind about the method of fusion. I think we should understand why
the Tokomak and magnetic containment has such a dominant position. It
is not suficient simply to heat the plasma, the plasma must be hot
long enough for useful power to be extracted. This is where inertial
metods, and as I understand it your method of containment is inertial,
break down.

Nuclear physics/thermodynamics have given us rates of vreaction at
various temperatures.

http://adsabs.harvard.edu/abs/1978trrd.rept.....B You should get a
copy of this is you are serious.

http://www.springerlink.com/content/gkhm317210541p35/ Interesting
paper on a form of "cold" fusion muons. Interesting this is being
investigated as a viable route. Muonic atoms will fuse cold.

http://en.wikipedia.org/wiki/Image:D...on_rxnrate.svg

This gives you the curve. It is NOT a primary source but it seems
fairly reliable. If you are serious what I suggest you do is calculate
a graph of temperature and density against time. Reaction rates will
be linear with density (frequency of collisions) so all you really
need is the temperature curve.

A great deal of research has been devoted to getting a stable plasma
in a tokomak so that the density/temperature/containment parameter
looks good.


- Ian Parker

"Doug" wrote in message
ps.com...

http://physicsworld.com/cws/article/indepth/30679

Comments?

Seems rather flawed. First, his comment

Apart from not even knowing for certain if there is any helium-3 on the
Moon,

is ignorant. Of course we know for certain there's 3He on the moon.
Doesn't he know Apollo returned a lot of lunar regolith, and that
this was analyzed rather heavily? If he had meant 'sufficiently
concentrated' or 'economically extractable', he should have said so.

Then, his discussion about tritium also misses the point. Yes, tritium
is produced, and some will fuse, but since the DD fusion rate is even lower
than D-3He, the total neutron flux per unit of power produced will
still be less than DT fusion. The benefit is not that the system
is aneutronic, but that the neutron flux is low enough that one
can plausibly expect to not have to replace the first wall of
the reactor every year or two, as one would have to do in
a DT reactor.

Overall, the lunar 3He claim is overhyped, but he could have
done a better job critiquing it.

Paul

In article . com,
Ian Parker wrote:

I have been thinking about this. I will agree that one should have an
open mind about the method of fusion. I think we should understand why
the Tokomak and magnetic containment has such a dominant position. It
is not suficient simply to heat the plasma, the plasma must be hot
long enough for useful power to be extracted. This is where inertial
metods, and as I understand it your method of containment is inertial,
break down.

I'm not sure what "your method" you're talking about, but IEC fusion
doesn't depend on heat at all, and that's the key point.

When you're using a thermalized plasma for fusion, you've got two
problems right off the bat:

1. The fuel ions are thermalized, meaning that they have a distribution
of energies. Put another way, at any given moment, most pairs of ions
will not have enough energy to fuse (since generally the temperatures
needed for this approach are so high that we can just barely achieve
them anyway). So this greatly reduces the probability of fusion when
two particles bump into each other.

2. The fuel ions are travelling in completely random directions. This
also greatly reduces the probability of fusion when two particles bump
into each other, since most of the time, you'll have something more like
a glancing collision than a head-on one.

One of the key insights of the IEC approach is that it is NOT using heat
to make ions fuse; instead, it is accelerating them together, much like
any other particle accelerator. Rather than flying around randomly,
fuel ions are accelerated electrostatically towards the focus at the
center. So whenever two ions bump into each other, they have the right
energy to fuse (curing problem 1); and because they're all being
accelerating towards the center, there is a higher probability of a
direct collision (partially curing problem 2).

So when referring to IEC fusion, don't talk about the temperature of the
plasma -- that's an inappropriate measure. Talk about the ion energy
(or velocity) instead.

A great deal of research has been devoted to getting a stable plasma
in a tokomak so that the density/temperature/containment parameter
looks good.

Yes, and a great deal more research will be done for decades to come, no
doubt. I'm not trying to take down tokamaks; some great physics comes
from them. But they're taking a very difficult approach to the problem,
and are unlikely to have much relevance to actual energy production. If
we'd spent even 10% of what's been spent on tokamak research on more
sensible approaches, we probably would have fusion power by now.

--
"Polywell" fusion -- an approach to nuclear fusion that might actually work.
Learn more and discuss via: http://www.strout.net/info/science/polywell/

On 29 Ago, 15:45, Doug wrote:

Comments?

EXCELLENT ARTICLE, INDEED

however, the main problem of (earth or lunar fueled) fusion is that it
(simply) doesn't work

we need more energy NOW and we have just three alternatives:

COMMERCIAL FUSION REACTORS:
- don't exist and will not exist for several decades (or could never
exist if its problems can't be solved)
- very expensive infrastructures
- mid/long time to build each power plant
- mid/low price (earth) "fuel" (or high price lunar He3)

OIL, METHANE, COAL, NUCLEAR POWER PLANTS:
- they exist now
- mid/high priced infrastructures
- mid/long time to build each power plant
- high/growing priced "fuels"

RENEVABLE SOURCES:
- they exist now and the energy already is price-competitive
- mid/low priced infrastructures
- mid/low time to build each power plant
- VERY LOW or ZERO priced "fuels" (sun, wind, waves, heat)
- ZERO chemical pollution and ZERO nuclear waste

of course, all renevable energies will play a role in future, but wind
energy is the fastest way to have more energy NOW

if a country needs an extra GW of installed power, they must only buy
200 wind turbines and put them on an unused land

then, within a few months, the extra-GW will be ready to be connected
to the electric net

On 30 Ago, 13:29, "Paul F. Dietz" wrote:

"...we know for certain there's 3He on the moon...Apollo returned a lot of lunar regolith..."

do you have an official NASA source about this? (with the exact amount
of He3 found in the Apollo samples)
all sources I've found don't talk of any He3 in the Apollo lunar
regolith samples
maybe, they are just a few "ATOMS"

"...the lunar 3He claim is overhyped..."

this is exactly the point, a few He3 "atoms" could be in the lunar
regolih, but not "ONE MILLION TONS" as claimed by lunar-He3 fans!

..

..

IF small amounts of Helium-3, Deuterium and Tritium will be found on
the Moon and, of course, IF the fusion reactors will give electric
energy, someday, they could be used to for LUNAR outposts/cities'
power generators and/or (maybe) to develop a fusion-based engine (if
possible) for Mars travels (however, these options are just sci-fi
now...)

..

On 30 Aug, 15:46, Joe Strout wrote:
In article . com,
Ian Parker wrote:

I have been thinking about this. I will agree that one should have an
open mind about the method of fusion. I think we should understand why
the Tokomak and magnetic containment has such a dominant position. It
is not suficient simply to heat the plasma, the plasma must be hot
long enough for useful power to be extracted. This is where inertial
metods, and as I understand it your method of containment is inertial,
break down.

I'm not sure what "your method" you're talking about, but IEC fusion
doesn't depend on heat at all, and that's the key point.

When you're using a thermalized plasma for fusion, you've got two
problems right off the bat:

1. The fuel ions are thermalized, meaning that they have a distribution
of energies. Put another way, at any given moment, most pairs of ions
will not have enough energy to fuse (since generally the temperatures
needed for this approach are so high that we can just barely achieve
them anyway). So this greatly reduces the probability of fusion when
two particles bump into each other.

2. The fuel ions are travelling in completely random directions. This
also greatly reduces the probability of fusion when two particles bump
into each other, since most of the time, you'll have something more like
a glancing collision than a head-on one.

One of the key insights of the IEC approach is that it is NOT using heat
to make ions fuse; instead, it is accelerating them together, much like
any other particle accelerator. Rather than flying around randomly,
fuel ions are accelerated electrostatically towards the focus at the
center. So whenever two ions bump into each other, they have the right
energy to fuse (curing problem 1); and because they're all being
accelerating towards the center, there is a higher probability of a
direct collision (partially curing problem 2).

So when referring to IEC fusion, don't talk about the temperature of the
plasma -- that's an inappropriate measure. Talk about the ion energy
(or velocity) instead.

A great deal of research has been devoted to getting a stable plasma
in a tokomak so that the density/temperature/containment parameter
looks good.

Yes, and a great deal more research will be done for decades to come, no
doubt. I'm not trying to take down tokamaks; some great physics comes
from them. But they're taking a very difficult approach to the problem,
and are unlikely to have much relevance to actual energy production. If
we'd spent even 10% of what's been spent on tokamak research on more
sensible approaches, we probably would have fusion power by now.

It would seem that what you are advocating isd a single pass. You
cannot get an appreciable percentage of atoms fusing on a single
encounter. If you have a hot plasma the atoms are travelling in random
directions - true, but they have a large number of collisions per
second. If you have 2 directed beams you cannot be certain of a hit,
still less of a square on hit.

You must vusualize an array of skittles placed a distance apart and me
aiming at them! Certain to miss.


- Ian Parker