Helium-3 Article in USA Today

"Christopher M. Jones" wrote:

Derek Lyons wrote:
It's equally hard to see how progress is going to be made if you never
progress beyond tons of small scale, limited goal experiments either.

I find it utterly fascinating that anyone could describe
projects costing hundreds of millions to billions of
dollars as "small scale".

Scale is determined by goals, not the size of the pile of dollars.

We don't know just how well tokomaks are going to be work with any
degree of certainty, and we won't know until we build one.

I think that maybe, just maybe, there have been more than
one or two tokamaks built over the years. I think you
maybe meant to make a different point there.

I meant "we don't know how suitable tokomaks are for long sustained
burns and potential power extraction".

D.
--
Touch-twice life. Eat. Drink. Laugh.

-Resolved: To be more temperate in my postings.
Oct 5th, 2004 JDL

"Paul F. Dietz" wrote:

The goal of all this is a commercially viable reactor. If tokamaks
can't deliver on that goal, continuing with the development is, at
some point, stupid, even if they are in a more advanced stage of
development than the alternatives.

Very true. But you and Christopher seems to claiming that we
shouldn't perform the very experiment that will validate or invalidate
tokomaks. Instead, we should be chasing after other systems less well
developed that may or may not themselves work.

D.
--
Touch-twice life. Eat. Drink. Laugh.

-Resolved: To be more temperate in my postings.
Oct 5th, 2004 JDL

Derek Lyons wrote:
"Paul F. Dietz" wrote:


The goal of all this is a commercially viable reactor. If tokamaks
can't deliver on that goal, continuing with the development is, at
some point, stupid, even if they are in a more advanced stage of
development than the alternatives.


Very true. But you and Christopher seems to claiming that we
shouldn't perform the very experiment that will validate or invalidate
tokomaks. Instead, we should be chasing after other systems less well
developed that may or may not themselves work.

Derek, what you are ignoring is that we already have a great
deal of experience with tokamaks. And we already have detailed engineering
designs of tokamak power reactors (PULSAR, STARLITE, the ARIES
series of designs). These designs have been heavily cost optimized.

And what do these detailed studies reveal? That getting tokamaks
to be competitive is going to be difficult. They need advanced
physics (better than what will be demonstrated in ITER, the current
conception of which doesn't even reach ignition, but is planned
to operate at Q ~ 10), they need to be big (2 GW(e)) and even then
they're only just competitive. The tokamak concept is just inherently
marginal, due to its topology, size, and its inefficient use of
magnetic fields.

Paul

Derek Lyons wrote:
"Christopher M. Jones" wrote:
Derek Lyons wrote:

No, it's a fact. Regardless of the machine chosen, you'll eventually
have to steel your courage, build a full size one, and hope.
Christopher on the other hand is advocating continuing small
experiments in the hope that one will produce cheap results.

I asked you kindly to not grossly mischaracterize my
position. Perhaps that was too much to ask of you,
Derek?

That's the position that you seem to be espousing.

It is not and never has been. I advocate cheaper experiments
because they seem to explore more useful parameter spaces,
because they provide more science return for their cost, and
because they are the appropriate direction to take at this
time, in my estimation. Moreover, as I said, characterizing
state of the art, billion dollar experiments as "small" or
"cheap" is erroneous at best and disingenuous at worst. You
have things completely backward, I wish to explore the best
routes to commercial fusion power sooner and more efficiently
while ITER purposes to gamble the majority of fusion research
funding on a questionable and outdated design.

Derek Lyons wrote:
"Paul F. Dietz" wrote:
The goal of all this is a commercially viable reactor. If tokamaks
can't deliver on that goal, continuing with the development is, at
some point, stupid, even if they are in a more advanced stage of
development than the alternatives.

Very true. But you and Christopher seems to claiming that we
shouldn't perform the very experiment that will validate or invalidate
tokomaks. Instead, we should be chasing after other systems less well
developed that may or may not themselves work.

I'm sorry Derek, but you appear to be grossly in error on
many points in your post. Firstly, you misdescribe ITER
as "the very experiment" when in reality it is merely one
experiment. Should we not expend our efforts on the
best experiment rather than simply the most ambitious or
expensive experiment?

Take a look at page 7 of this summary:
http://fire.pppl.gov/ARIES_FIRE_ITER_nrc.pdf

Or read this summary of the Fusion Ignition Research
Experiment (FIRE) he
http://fire.pppl.gov/bpac_fire_091802f.pdf

Then tell me why ITER is the best choice to explore fusion
reactor designs?

Secondly, you claim that I am advocating chasing after
"less well developed" systems, when the opposite is the
case. FIRE represents less extrapolation from currently
explored plasma regimes, period.

Thirdly, I am not advocating abandoning tokamak designs,
FIRE is precisely a tokamak design and I am in favor of
building it. I do think we ought to be exploring other
design alternatives at a level of funding appropriate
for pure science research (i.e. much less than what we
spend on tokamaks but still significant), but that's a
separate issue.

Fourthly, ITER is not an expriment capable of validating
or invalidating the tokamak design for fusion power
production. No individual experiment can be, though
results can be suggestive. Since ITER does not explore
the areas of most interest with regard to plasma
conditions in power production fusion reactor designs,
it is particularly ill suited to rule in or rule out
such designs.


My estimation (and I admit to being far from an expert
in these matters) is that ITER is more risky, will
provide less useful data, and will be much more expensive
than alternatives such as FIRE. Which is why I believe
ITER to be a waste of money. If it were the only option
on the table it might, perhaps, be worth building, but it
is not. We have better options now, we need to exploit
them.

I wrote:

And what do these detailed studies reveal? That getting tokamaks
to be competitive is going to be difficult. They need advanced
physics (better than what will be demonstrated in ITER, the current
conception of which doesn't even reach ignition, but is planned
to operate at Q ~ 10), they need to be big (2 GW(e)) and even then
they're only just competitive. The tokamak concept is just inherently
marginal, due to its topology, size, and its inefficient use of
magnetic fields.

To expand on this further: they are only possibly just
competitive for generation of electric power, when compared
against other *current* technologies. For other uses of energy,
such as in transportation fuels or smelting of ores, they are even
less competitive. To displace fossil fuels in those markets
requires even cheaper energy.

Moreover, 40+ years from now, when tokamak-based reactors
might come onto the market, the competition for electric
power will not have stood still. Renewables and fission
reactors will have advanced down their learning curves
(renewables particularly so), and will also be much less
risky to potential investors.

What this all means is that for fusion to be taken seriously,
it has to be more than competitive, it has to decisively
beat the current alternatives. Tokamaks don't.

Paul