He3 from Moon regolith

On May 24, 2007, at 03:31 UTC, Chris Smyth wrote:

> I watched a program on The Learning Channel entitled "Moon for Sale".
> The main thrust of the justification for returning to the Moon with a
> permanent presence, according to the show, is the relative abundance
> of He3 in the lunar regoloith.

That's a big giant hairy red herring, IMHO.

> He3 will purpotedly enable the development
> of fusion reation power plants (on Earth) without the substatial
> neutron flux that hydrogen fusion produces (and which constitutes a
> significant loss of power production eficiency and greatly increases
> the deterioation of the confining vessle sidewalls).

Using what technology? The only approach to fusion I've seen that has
even a reasonable chance of working is the Bussard polywell reactor,
and that doesn't need He3 -- it'll burn hydrogen and boron, which are
literally dirt-cheap right here on Earth. For more info, see:
http://www.strout.net/info/science/polywell/

> Leaving aside for now the aruments about the relative benefits and
> disadvantages of He3 fusion reators versus Spaced based Solar Power

You mean like, space-based solar power uses existing technology and He3
fusion is a pipe dream? :)

> I'm curious about how sure researchers are about the do-ability of He3
> fusion reactors.

Good for you. That is indeed the key question. And the answer is,
most researchers are pretty certain that it'll never be practical, even
if it ever becomes possible. Certainly not with currently popular
approaches to fusion (e.g. tokamak reactors).

> Specifically, I wonder how much research, development,
> and construction time might be required the build a He3 power
> producion fusion reator here on Earth if sufficient He3 were
> available.

We've been pouring billions into fusion research over the course of
decades. There's no evidence that any amount of research, development,
and construction time would actually make it work with conventional
approaches.

Conversely, Bussard figures he needs about $5M and a couple years to
build his next subscale demo reactor, confirming results obtained with
WB-6 just before one of the magnets shorted out and destroyed the
machine; and maybe $200M-$300M and 5-10 years to build a full-scale,
net-positive fusion plant. But it won't have any need of He3.

(It will, however, open up the solar system pretty much overnight,
because a fusion reactor makes an extremely powerful rocket motor.)

> Anyone have any thoughts on this?

Not me. :)

Cheers,
- Joe

Joe Strout -- joe@...
Strout Custom Solutions