EMC2 news

Point out news stories, on the net or in mainstream media, related to polywell fusion.

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crowberry
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Re: EMC2 news

Post by crowberry »

Dr Jaeyoung Park has given a talk Polywell Fusion: 30 years and Ready for Commercialization at the ALPHA 2017 Annual Review Meeting August 29-31, 2017 https://arpa-e.energy.gov/sites/default ... 5_PARK.pdf. The simulation work hinted at by ladajo is mentioned in the presentation.

Which is the second patent application that is mentioned in the talk?

There is a lot of more interesting presentations to read at the meeting site: https://arpa-e.energy.gov/?q=site-page/ ... ew-meeting

Diogenes
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Re: EMC2 news

Post by Diogenes »

krenshala wrote:
Diogenes wrote:I am well aware that many people with computer science degrees are highly concerned about code efficiency. My point here is that while it may be desirable, it isn't essential for this purpose that the code be efficient. What is essential is that it gets the physics right, and if you accomplish that bit, how long it takes to run a simulation is really irrelevant to the problem, isn't it?


Efficient Code is good, but not a necessity. Code that gets the physics accurate is the necessity.
The issue is not "inefficient code is bad", but instead is "inefficient coders can do things wrong with the code, and the results from that aren't obviously incorrect, leading to really bizarre bugs -- some of which aren't even noticeable unless you already know what the correct (physics) answer is before you run it through the computer, and sometimes its not obvious even then."

I find it highly improbable that the people entrusted with this work do not know how to code properly. It never occurred to me that there should be any question regarding their competence. For one thing, the output would demonstrate it if that were the case.
‘What all the wise men promised has not happened, and what all the damned fools said would happen has come to pass.’
— Lord Melbourne —

Diogenes
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Re: EMC2 news

Post by Diogenes »

ScottL wrote:
krenshala wrote:
Diogenes wrote:I am well aware that many people with computer science degrees are highly concerned about code efficiency. My point here is that while it may be desirable, it isn't essential for this purpose that the code be efficient. What is essential is that it gets the physics right, and if you accomplish that bit, how long it takes to run a simulation is really irrelevant to the problem, isn't it?


Efficient Code is good, but not a necessity. Code that gets the physics accurate is the necessity.
The issue is not "inefficient code is bad", but instead is "inefficient coders can do things wrong with the code, and the results from that aren't obviously incorrect, leading to really bizarre bugs -- some of which aren't even noticeable unless you already know what the correct (physics) answer is before you run it through the computer, and sometimes its not obvious even then."
This a hundred fold. Krenshala hit the proverbial nail on the head. Bad coders make simple mistakes. A great and exceedingly common example is choosing the wrong data type. You choose the wrong one and you could be introducing round errors that could have a domino effect across your entire model. As I mentioned before, I'm not saying they don't have some top notch coders, but we honestly don't know. When it comes to work like this though, I can tell you rounding errors should be a legitimate concern.

Do you honestly think these people don't know the difference between data types for a piece of software that is heavily dependent upon high accuracy calculations?


Somehow I think it's all under control.
‘What all the wise men promised has not happened, and what all the damned fools said would happen has come to pass.’
— Lord Melbourne —

ScottL
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Re: EMC2 news

Post by ScottL »

Diogenes wrote:I find it highly improbable that the people entrusted with this work do not know how to code properly. It never occurred to me that there should be any question regarding their competence. For one thing, the output would demonstrate it if that were the case.
Diogenes wrote:Do you honestly think these people don't know the difference between data types for a piece of software that is heavily dependent upon high accuracy calculations?

Somehow I think it's all under control.
Maybe, probably, but...
https://en.wikipedia.org/wiki/Mars_Climate_Orbiter

People make mistakes all the time, including these people.

mvanwink5
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Re: EMC2 news

Post by mvanwink5 »

Scott, I bet the mistake was implemented efficiently and miscalculations were sufficiently accurate. :D
Counting the days to commercial fusion. It is not that long now.

mvanwink5
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Re: EMC2 news

Post by mvanwink5 »

Gruberment projects are always 20 years away. Dark horse projects are always 3-5 years away. Difference is that the Dark Horse projects are getting to the size needed to know and plan for commercial, at the same time that risk and uncertainty justifies the exponential cost for the prototype size test machines.

A big new factor is that simulation is becoming impressive for all companies. Big news for plasma certainty.
Counting the days to commercial fusion. It is not that long now.

Diogenes
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Re: EMC2 news

Post by Diogenes »

ScottL wrote:
Diogenes wrote:I find it highly improbable that the people entrusted with this work do not know how to code properly. It never occurred to me that there should be any question regarding their competence. For one thing, the output would demonstrate it if that were the case.
Diogenes wrote:Do you honestly think these people don't know the difference between data types for a piece of software that is heavily dependent upon high accuracy calculations?

Somehow I think it's all under control.
Maybe, probably, but...
https://en.wikipedia.org/wiki/Mars_Climate_Orbiter

People make mistakes all the time, including these people.

Or the incident in which the Patriot batteries didn't fire to take out a scud missile in Iraq because someone had used a float when they should have used an int. It showed up as a failure after days of operation. The Scud hit a barracks and killed a lot of our people.


But I think Plasma physics simulation written for a super computer is an entirely different level of programing than that of a weapons system controller or that of a robot.
‘What all the wise men promised has not happened, and what all the damned fools said would happen has come to pass.’
— Lord Melbourne —

mvanwink5
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Re: EMC2 news

Post by mvanwink5 »

Each supercomputer made of thousands of parallel processors takes special coding. I would not be surprised if the machine owner has his own coders that you use to implement your program.
Counting the days to commercial fusion. It is not that long now.

ladajo
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Re: EMC2 news

Post by ladajo »

crowberry wrote:Dr Jaeyoung Park has given a talk Polywell Fusion: 30 years and Ready for Commercialization at the ALPHA 2017 Annual Review Meeting August 29-31, 2017 https://arpa-e.energy.gov/sites/default ... 5_PARK.pdf. The simulation work hinted at by ladajo is mentioned in the presentation.

Which is the second patent application that is mentioned in the talk?

There is a lot of more interesting presentations to read at the meeting site: https://arpa-e.energy.gov/?q=site-page/ ... ew-meeting
A shame the videos aren't posted. Y'all would like them.
The development of atomic power, though it could confer unimaginable blessings on mankind, is something that is dreaded by the owners of coal mines and oil wells. (Hazlitt)
What I want to do is to look up C. . . . I call him the Forgotten Man. (Sumner)

Tom Ligon
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Re: EMC2 news

Post by Tom Ligon »

About this matter of physicists not being good at code and software geeks not being good at physics, why would anyone believe you can't have both on a team and have them learn something about each other's craft?

This is why Dr. Bussard hired Kitty King and later Loren Jameson to work with him prior to me coming aboard.

Kitty was versatile enough that she quit software and is now a lawyer. Loren got tired of unreliable funding and got into writing computer games, including a bitchin' good combat flight simulator he brought by one day and I got to try out.

It does take a while to wrap one's head around the function of the Polywell, but it is all just physics. And physics can be taught to programmers. They get math and hopefully can speak that common language with physicists.

The best way to check their work is to have good experimental results. Dr. Park provided that. When the experiment did not match Dr. Bussard's original suppositions, he revisited the theory, illuminated by good experiments, found the problem, and built the little machine to generate wiffleballs. They now apparently have the models to properly understand what Dr. Bussard, quite honestly, pretty much understood but tended to fill in the unknowns with wishful thinking. Bussard had it generally right but needed to bang the machine much harder to get the holes to close up.

A software glitch such as the one that doomed that Martian lander is revealed by experiment. Alas, uncoveriing it by crashing on another planet is inefficient. No doubt there were mistakes made in generating the present code ... I do recall writing one assembly language driver that worked perfectly on the first try ... total fluke. Most software has bugs and if you're good you find and fix them. They've got a ton of data to work with, so if they ran into some curious and quaint plasma physics units conversion, I'm sure they found them. Leaving out a 2*pi is one I remember catching on an RWB calculation. Oddball units such as measuring plasma pressure and magnetic pressure in atmospheres rather than Pascals are endemic to the field. After a couple of years banging the code and comparing it to test results, I have to suspect that's pretty well dealt with. The crashes to the surface to Mars were done quietly in a computer, found, and fixed.

At this point the wishful thinking is in the projections for getting larger machines built. The wish here is that money and support be forthcoming, steady and adequate. 10 years? If the conditions above are achieved, why not. If there were a war on and this were essential to the effort, it could probably be done in four (see the Manhattan Project). The big unknown is the quality of the support.

ladajo
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Re: EMC2 news

Post by ladajo »

The quality of support is very high.
What has been learned from the lab and the sim work has been significant, and has advanced the theory.
More to follow, be patient.
Any comments on the presentation (albeit sans videos)?
The development of atomic power, though it could confer unimaginable blessings on mankind, is something that is dreaded by the owners of coal mines and oil wells. (Hazlitt)
What I want to do is to look up C. . . . I call him the Forgotten Man. (Sumner)

Tom Ligon
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Re: EMC2 news

Post by Tom Ligon »

Part of my last post was informed by the slides. Slide 3 is an update of images Dr. Bussard used since back in the 90's, the WiffleBall. It appears to be fresh art, and has simplified the explaination (RWB showed two paths to the WiffleBall). In slide 7 we can see "Breakthrough: Wiffle-Ball", together with a first principle plasma simulation using a supercomputer. This suggests that the original concept holds, at least if you can get the plasma conditions right.

This, by the way, proves Grad's Conjecture, the underlying idea that makes this thing work that RWB somehow managed to never credit.

http://fire.pppl.gov/FPA14_IECM_EMC2_Park.pdf

His earlier talks after the WB Mini machine achieved beta = 0.7 on a single injector (thus almost certainly beta = 1 with six injectors) went into the importance of beta in considerable detail. This is the ratio of plasma pressure to the magnetic confinement pressure. Because of the stable convex field configuration (which I believe is also a factor in Tri-Alpha's FRC machine and probably the LM effort), it should be possible to push all the way to Plasma Pressure = Magnetic Pressure. Compare this to tokamaks, which, assuming the same magnetic field strength using comparable superconducting magnets in a final design can only be pushed to beta of about 0.05, maybe 0.1 if you are feeling really brave, before instability in their concave configuration puts plasma into the walls. Most experiments seem to run at about 0.01.

From slide 24 in the talk linked above:

Teller’s Comment on Beta

“ The qualitative properties of the plasma depend on the ratio of
pressures in the plasma and the magnetic field. The former is
the plasma pressure p, the latter B^2/8π. The ratio of the two
quantities is known as β. In general, the plasma behavior
is most simple for low-β values and most interesting for high-
β values.”
Teller, page 13-14, “Fusion ,Volume 1, Part A: Magnetic
Confinement, edited by Edward Teller, 1981

Why did Teller think high beta is interesting? Because fusion reactions are expected to scale as plasma pressure squared. So given the same magnetic pressure, increasing beta from 0.05 to 1, means plasma pressure can increase by a factor of 20, and fusion rate by a factor of 400.

I presume the talk delivered this part verbally. The Polywell, and other high beta approaches, should whip the pants off tokamaks, which we are assured by The Authorities will one day work. Hence the huge level of optimism among the people pursuing high beta.

ladajo
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Re: EMC2 news

Post by ladajo »

A key statement is made on Slide 8. Don't overlook what it means. It also couples back to Slide 7.
I just noticed a couple of typos. Makes me sad. I should have caught them long ago.
The development of atomic power, though it could confer unimaginable blessings on mankind, is something that is dreaded by the owners of coal mines and oil wells. (Hazlitt)
What I want to do is to look up C. . . . I call him the Forgotten Man. (Sumner)

Tom Ligon
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Re: EMC2 news

Post by Tom Ligon »

ladajo wrote:A key statement is made on Slide 8. Don't overlook what it means. It also couples back to Slide 7.
Indeed. I did not mention this slide because, as stated, it lacks some supporting images that tell the real story. "The holes are closed." The WiffleBall does indeed form. One presumes there was some mention of the Lawson Criterion about this point in the talk and the benefits of boosting confinement time by closing the holes.

So multiply that increase of 400 by some additional factor.

The factor of 400 I calculated supposes one runs a Tokamak at beta = 0.05. Another number I find for tokamak beta is 0.03. I just found a very specific calculation of 0.028. So let's turn the crank on that one. Increasing from 0.028 to 1.000 improves plasma pressure by 35.7. Square that and get an increase in fusion rate of 1275.

That's just back-of-envelope stuff, of course. The point of the latest presentation is that they now have the model supporting experiment and they're pushing it to larger scales. The whole point of this work has been to determine how this system will scale in order to lay out the following steps intelligently and have a good chance of not pissing off the investors with a miss. Park really hates doing that, and tends to make conservative estimates.

You will now appreciate slide 9 better, and the ones that follow it. I met Nebel and Park when they first took this on, and they discussed their views as we shared a meal after RWB's wake. They found the concept interesting, and promising if they could replicate the experiments and prove it, first to their satisfaction and then to the fusion community. They had their reservations. Those reservations are now, um, greatly reduced. Park seems to think he's got this. And from what I know of him, he's very cautious until he is absolutely sure. Unless the sulfur hexafloride fumes have affected him and changed his nature, what we're seeing here is "give me the resources and watch this."

ladajo
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Re: EMC2 news

Post by ladajo »

There is an inherent circulation of (e-)s which generates additional fields and interactions beyond the machine magnets. It is, in my mind, and very much chicken/egg process as the standing fields, electron motion (dependent initially on static fields), electron generated fields, and electron density (functions of dynamic plasma pressure changes due to leakage, fields, and containment factors) work with and against each other. All of this complexity has been seen (and shown) to lead to increased containment as the cusps, in effect, self plug as plasma pressure builds. This is a really good thing. I don't think it is my place to spit out numbers. However, I am very interested to see how scaling of various factors, independently and together, works out. If things work as they are understood currently, some interesting days indeed lay ahead. That said, "if it was easy, everyone would do it."

I agree with your assessment regarding Dr. Park and his conservatism. A very careful man, who prefers to undersell, as he does not wish to attest to things which are not proven. A true scientist in my opinion.
The development of atomic power, though it could confer unimaginable blessings on mankind, is something that is dreaded by the owners of coal mines and oil wells. (Hazlitt)
What I want to do is to look up C. . . . I call him the Forgotten Man. (Sumner)

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