Talk-Polywell.org

http://news.sciencemag.org/scienceinsid ... ion-o.html

How much will the international fusion experiment called ITER really cost? That's what four U.S. senators want to know, and today they sent a letter to the U.S. Government Accountability Office (GAO) requesting an investigation of the current cost and schedule for the gargantuan experiment, under construction in Cadarache, France. They're also interested in possibilities for reducing the cost of the United States' share of the hardware, in part because of worries that ITER's ballooning costs are consuming the U.S. domestic fusion program.

"At a time when federal budgets for research are likely to be constrained for the foreseeable future, concerns have been raised that funding for other U.S. fusion energy science programs and user facilities have [sic], and may continue to be, cut to pay for increasing ITER costs," write Dianne Feinstein (D-CA) and Lamar Alexander (R-TN), the chair and ranking member of the Senate Appropriations Subcommittee on Energy and Water Development, and Ron Wyden (D-OR) and Lisa Murkowski (R-AK), the chair and ranking member of the Senate Committee on Energy and Natural Resources. GAO is Congress's investigative arm, and lawmakers frequently ask it to review projects that have raised budgetary flags.

Are there aspects of ITER that will yield data of use to other fusion projects? So maybe ITER (or similar) will never become commercially viable, but maybe there is valuable data that will help polywell or tri-alpha or whatever?

A better way to ask might be, is ITERs design capable of yielding data of use to other fusion projects. And to the extent that it just may be worth the cost?

rj40 wrote:Are there aspects of ITER that will yield data of use to other fusion projects? So maybe ITER (or similar) will never become commercially viable, but maybe there is valuable data that will help polywell or tri-alpha or whatever?

A better way to ask might be, is ITERs design capable of yielding data of use to other fusion projects. And to the extent that it just may be worth the cost?

There is no way to answer that question in advance. All you can say is that the odds are against it.

One way to visualize the issue is... how many stars have you seen that are known to be toroidal?

Does everything man made have to mimic nature?

KitemanSA wrote:One way to visualize the issue is... how many stars have you seen that are known to be toroidal?

Dear Kiteman, for your reference, geometrically spherical is a vacuous case of toroidal when minor radius is equal to nil.
The second question is how correct is to compare gravitational confinement geometry with magnetic? May be or not that what is good for gravitational is not obligatory good for magnetic.

I have to agree that the "no toroidal stars" argument against the tokomak and other toroidal devices is weak. Unfavorable field curvature is a much stronger argument.

hanelyp wrote:Unfavorable field curvature is a much stronger argument.

Please prove that TOKAMAKs have "Unfavorable field curvature".
I am afraid that you can quote nothing more than Bussard's reasonings.
Once again, if to compare two toroidal devices TOKAMAKs and Stellarators and to follow to Bussard's reasonings about advantage of convex fields, Stellarators should provide better confinement.
But reality is that namely TOKAMAKs provide better.

Stubby wrote:Does everything man made have to mimic nature?

Certainly not. But neither is it wise to refuse to learn from it. Nature has a way of finding the simplest way to do something within the bounds of the possibilities open to it. The simplest way for fusion seems to be spherical.

hanelyp wrote:I have to agree that the "no toroidal stars" argument against the tokomak and other toroidal devices is weak. Unfavorable field curvature is a much stronger argument.

Which is what you get with toroids.

KitemanSA wrote:

hanelyp wrote:I have to agree that the "no toroidal stars" argument against the tokomak and other toroidal devices is weak. Unfavorable field curvature is a much stronger argument.

Which is what you get with toroids.

Toroids are problematic because of the field curvature they produce, not because there are no toroidal stars.

Joe, how someone that knows so much about plasma physics to not know about so call good curvature and bad curvature is beyond me.

Robthebob wrote:Joe, how someone that knows so much about plasma physics to not know about so call good curvature and bad curvature is beyond me.

continuous (infinite) toroidal is worse than full of holes (casps)? If to recall that always casp losses in all earlier built machines were exceeded expected values.
Or do you think that Polywell is the first casp machine in history of fusion research?

If you again are repeating the popular in middle years of last century myth about "advantage" of convex fields what can you say about the so called "twist" provided by both Stellarator and TOKAMAKs? Did you know about twist’s role? Bad role?

Flat "convex" there is a special case of spatial "the minimum B principle" as analytically both these cases can be described by positive field gradient. TOKAMAK provides negative gradient, while Stelarator - positive. Nevertheless TOKAMAKs always provided better confinement. That is proven and well known fact.
So, your beloved advantage of convex fields is only the non-proven myth.

Robthebob wrote:Joe, how someone that knows so much about plasma physics to not know about so call good curvature and bad curvature is beyond me.

I've long since concluded that Joe is a literal bird brain in relation to the tokomak, parroting articles he's read without really understanding what he's reading.

hanelyp wrote:

Robthebob wrote:Joe, how someone that knows so much about plasma physics to not know about so call good curvature and bad curvature is beyond me.

I've long since concluded that Joe is a literal bird brain in relation to the tokomak, parroting articles he's read without really understanding what he's reading.

Thanks. Please answer if you understand better on these 4 questions:

1. I am really do not understand what is better: better confinement or worse confinement?

2. I am really do not understand what is better: is flat plane "convex" analitically similar to "minimum-B principle" (as in both cases dB/dr>0)?

3. I am really do not understand what is better: Stellarator - the typical "minimum-B" macine or TOKAMAK with dB/dr<0 but nevertheless providing better confinement?

4. I am really do not understand what is better: endless power lines or full of holes?

Please show your understanding and explain instead of speaking common but meaning nothing phrases "bad curviture" or "parroting articles he's read without really understanding what he's reading".
Please show what I do not understand and you do.