Mechanical Design: Open FEM

Open FEM is a mechanical design program that can help figure out the stresses and strains caused by the magnets in a Bussard Fusion Reactor. It is based on Scilab, a numerical computation program.

H/T Prometheus Fusion Perfection

Free Plasma Physics Book

You can read reviews and buy a hard copy of Plasma Physics and Fusion Energyby clicking on the link.

Or you can get a pdf of the book at this detailed review or by going directly to the download link.

The book is very much tokamak oriented so the calculations have limited value for plasmas that are far from thermal equilibrium. However, the ideas presented are of interest to anyone working with plasmas.

Steampunk Fusion

The picture you see above is a steam driven fusion reactor. I know what you are thinking. This is some kind of joke. It is no joke. General Fusion has a design that I think has an outside chance of working.

I was discussing it with some of the boys at Talk Polywell and I'd say it has no fundamental flaws.

Popular Science also gives some of the details of the machine and its inventors. The drawing at the top of the page shows a schematic of the machine that has 200 pistons. Now to give you some idea of the scale here is a picture of one of the pistons.

Huge sucker huh? Now imagine 200 of them all firing away at the rate of once a second. When the piston hits (and yes it will hit) the end of the cylinder it will be going about 250 mph and it will induce a shock wave into a sort of ball of liquid lithium and lead. But first two rings of counter rotating plasma will be shot into the middle of the rotating metal and then all the steam (yeah steam) driven pistons will fire and hit the molten metal with a timing of better than one microsecond.

Can it be done? My rough calculations at the above Talk Polywell link say yes. Not easy, but possible. So would I put money on it? Not me. But I'm an IEC Plasma Fusion type of guy. However, if the idea excites you (a steam driven fusion reactor) I'd say it has as much a chance of working as anything being done now. Definitely worth a shot. And besides how many of your friends can say they are investing in a steam driven fusion reactor? It has got to be worth some bucks just for the conversation starter value alone.

Rick Nebel Updates The Latest News

From Cosmic Log:

First of all, our work has been peer reviewed. An independent panel of experts has looked at these results. I don’t believe that there was anyone on the panel who has less than 40 years experience working with magnetic confinement. It included senior professors and people who have managed the fusion program. We asked them for their honest opinions and that’s exactly what we got. We are proceeding with our program in line with their recommendations.

Secondly, the talk-polywell blog has a large variety of people who post there. There are Phd plasma physicists as well people from the general public. I think that’s a good thing. Science needs to be accessible to people.

Rick Nebel (Sent Saturday, December 20, 2008 12:08 PM)

and

Yes, there are neutrons and the numbers are consistent with the plasmas we are measuring. However, neutrons can be deceptive. A lot of fusion researchers have gotten in trouble in the past by relying on these types of measurements. You need to know where they come from and that's difficult to measure.

R Nebel (Sent Saturday, December 20, 2008 4:31 PM)

Discussed at Talk Polywell. This is one of the places (among several) at the board where the news is being discussed.

Liquid Cooled Grid IEC Reactor

Roger at Talk Polywell provides a link to experiments done with a liquid cooled grid Farnsworth - Hirsh type IEC Fusion device. The device uses a magnetron type ion injector.

You can read about it at RTF Technologies.

I especially recommend the paper describing the construction [pdf].

IEC 2008 - Kyoto

I just received a report on the IEC Fusion 2008 conference from Joel Rogers - one of the participants. This is a report of the conference schedule which has links to the abstracts of the papers presented. You can also see the poster for the conference [pdf] which has a very nice picture of a temple on the Uji-Campus of Kyoto University.

Uji is surrounded by beautiful landscapes centering on the Uji River with more than a thousand years of history. It is abundant with historical assets including Byodoin Temple and Ujigami Shrine, both of which are registerd in the UNESCO world heritage list. A lot of historical assets and autumn tints in early December attract many visitors to Uji.

The Byodoin Temple was first a villa owned by Fujiwara Michinaga, the model for the hero Genji in the Tale of Genji. Then in 1052 it was converted into a temple by his son. The central hall in the above photo is popularly known as Hoohdo (Phoenix Hall), an image of which is found on 10-yen coins.

Here is the abstract of the talk [pdf] Dr. Rogers gave.

IEC Polywell[2] is a candidate for commercial power generation. Particle-in-cell simulation was used to follow the time sequence of plasma development starting from neutral deuterium gas in a cubic Polywell. The left figure below shows electrons flowing in and out of the core along 8 cusp lines. The 8 rectangles are 1.0kG coil-magnets separated by 30cm (inside core diameter) and biased to 15kV. Electron guns (5A) are centered on the 4 vacuum tank walls, held at 0V. The center figure shows the ion distribution at Beta ≅ 1 density. Bounded by a 2cm thick shell, the interior ion population is uniform inside the shell. The shell is composed of ions that have slowed prior to reflecting at the edge of the potential well. The right figure shows the ion velocity (U) population. The flat top indicates uniform inside magnitude, |U| = 1.3x10E6m/s (18keV). The fusion rate was computed as n2·<σ(v)·v>·a3/2, where n is the ion density (n=1.1x10E11/cm3), σ is the parameterized DD fusion cross section, v is the ions’ relative velocity, and a is the diameter(20cm) of the ~cubic volume inside which the velocity is uniform. Substituting the simulated n, v, and a, resulted in a fusion rate prediction of 9x107 fusions/s, in fair agreement with Bussard's measured WB-6 neutron rate[2]. The simulation predicts the following features of Polywell: (1) Electrons circulate out and in freely along cusp lines. Very few electrons hit the magnets. (2) Ions are trapped in an electrostatic potential well, which maintains a steady state, spatially uniform, monoenergetic ion population long enough for substantial fusion to occur.
(3) The surface density of trapped electrons corresponds to a Beta value on the order of unity.

Particles reaching the tank wall will generate electricity efficiently while particles hitting the magnets will generate electricity less efficiently. The effective power gain factor (Q) can be estimated as the ratio of fusion power output to the portion of electric power input spent to replace ions hitting the magnet boxes. Simulated Q-factor as a function of device size has predicted the size of a steady state, break-even (Q=1) device which needs to be tested.

The pictures mentioned are included in the pdf.

WB-6 Results Confirmed - Continuous Operation The Next Step

Alan Boyle at Cosmic Log announces the results of the WB-7 Bussard Fusion Reactor (BFR) experiments. And the results? No show stoppers so far.

An EMC2 team headed by Los Alamos researcher Richard Nebel (who's on leave from his federal lab job) picked up the baton from Bussard and tried to duplicate the results. The team has turned in its final report, and it's been double-checked by a peer-review panel, Nebel told me today. Although he couldn't go into the details, he said the verdict was positive.

"There's nothing in there that suggests this will not work," Nebel said. "That's a very different statement from saying that it will work."

By and large, the EMC2 results fit Bussard's theoretical predictions, Nebel said. That could mean Polywell fusion would actually lead to a power-generating reaction. But based on the 10-month, shoestring-budget experiment, the team can't rule out the possibility that a different phenomenon is causing the observed effects.

"If you want to say something absolutely, you have to say there's no other explanation," Nebel said. The review board agreed with that conservative assessment, he said.

The good news, from Nebel's standpoint, is that the WB-7 experiment hasn't ruled out the possibility that Polywell fusion could actually serve as a low-cost, long-term energy solution. "If this thing was absolutely dead in the water, we would have found out," he said.

If Polywell pans out, nuclear fusion could be done more cheaply and more safely than it could ever be done in a tokamak or a laser blaster. The process might be able to produce power without throwing off loads of radioactive byproducts. It might even use helium-3 mined from the moon. "We don't want to oversell this," Nebel said, "but this is pretty interesting stuff, and if it works, it's huge."

The next step in my opinion should be a continuously operating version about the size of WB-7. A device I used to call WB-7x and will probably be called WB-8.

Here are some links to what I think a liquid nitrogen (LN2) cooled magnet coil WB-8 (WB-7x) should look like.

Design Issues including laboratory equipment.
Reactor Vessel Requirements.
LN2 Storage
Magnet Power Supplies
Reactor Building And Reactor Controls
Power Supplies Update #1
Reactor Building Sketches
Electron Guns
Lab Tools
Other Instrumentation - Mass Spectrometer
Research Speed
PID Loops And Leak Valves
Orifice Sizing for leak valves.
Thinking About Control
Ionization Pressure Gauges
Detectors
Turbo Pump Ratings
Gas Valve Design
Data Collection
Vacuum Pumping
Transimpedance Amplifiers
The First Wall Problem
WB-6 Shopping List
LC POPS
Standardizing Fusion Test Reactors
Gauging With Intent
CAN Bus And System Control
Magnetic Field Measurement

For those of you not up to speed on the basics may I suggest:
Easy Low Cost No Radiation Fusion
The World's Simplest Fusion Reactor Revisited

And for those of you who would like to join in on the research at a very modest cost may I suggest Starting A Fusion Program In Your Home Town. There is a lot that can be learned from these very simple devices and some simple instrumentation. There is so much we don't know yet.

H/T Instapundit

Amateur Nuclear Fusion - The Book

I just came across a book Amateur Nuclear Fusion that is the tale of one guy's efforts to make neutrons in his basement. Here is the blurb from the book:

Here's a look inside an amateur lab that does nuclear fusion. I outline the basic principle of the Farnsworth fusor, and describe my fusor in detail, accompanied with tales of its construction.

The book is not expensive at $12.50 but even better you can get it as a free down load. Both are available at the above link.

H/T Open Source Fusor Consortium

Incoming Energy Secretary On Bussard Fusion

In this Google Tech Talk from about 28 February 2007 you can see Incoming Energy Secretary Steven Chu discussing what he knows about Bussard Fusion about 1 hour 1 minute and 10 seconds into the video. The rest of the talk is about alternative energy, power sources for the future, and how to run a good development program. And what does he know about Bussard Fusion Reactors? Not much. He is looking into it.

I got the heads up from cybrbeast at Talk Polywell.

Tom Ligon To Talk About IEC Fusion Developments

Tom will be at the Philcon Science Fiction convention this coming Saturday, 22 Nov 2008. You can read what Tom has to say about his upcoming talk at Talk Polywell.

New IEC Fusion Experiment Contract

FedBizOpps.gov has a solicitation for a bid for more experiments by EMC2, Doc Bussard's company now being run (at least on the experimental side) by Rick Nebel.

The Naval Air Warfare Center, Weapons Division, China Lake, CA intends to procure on an other than full and open competition basis a service to provide: 1) Research of Electrostatic "Wiffle Ball" Fusion Device. The contractor is to specifically investigate the required instrumentation to achieve spatially resolved plasma densities and spatially resolved particle energies. This requirement is sole sourced to Energy Matter Conversion Corporation, 1202 Parkway Drive, Suite A, Santa Fe, NM 87501, as the only company in the world investigating and developing this type of device.

What does that mean in terms of progress with the Bussard Fusion Reactor? It means that the experiments delineated in the Fusion Report 29 August 2008 had at least enough success to warrant further work.

Dave Price has some thoughts and more details.

Fusion Report 20 October 2008

Alan Boyle brings us up to date on the latest news from the world of fusion. Of course I'm especially interested in what he has to say about Bussard Fusion and their progress to net power. I'll give you the short version:

"We've been pretty busy, but it's the same situation," Nebel told me today. "We're kind of in a holding pattern."

He's been able to keep the five-person team together and "doing a few things" during this holding pattern. There have been some rumblings to the effect that EMC2's results have been encouraging enough to justify pressing forward, but Nebel has declined to make a prediction about the project's future.

Nebel worries about the same kind of budget limbo that the U.S. ITER team is worrying about, even though his budget is an order of magnitude lower. Among the factors on his mind are the change in the White House and the changes in economic circumstances.

"The thing that usually gets hit the hardest is what they call discretionary funding," Nebel said, "and that's what we're looking at here. That'd be the biggest fear everywhere."

So the news is the same as it was at the end of August. No news. Alan Boyle has more on fusion power in general and Bussard Fusion in particular. You can also read my previous Fusion Reports by following the links in: Fusion Report 29 August 2008.

A New Sigma

My friend Tom Ligon has just been inducted into the Sigma Society. Here is what Sigma does:

Many SIGMA members are Ph.D.-level scientists and engineers; all are science fiction writers who have spent careers applying their technical and literary talents in exploring the future of science, technology, society and cultures. SIGMA provides a significant pool of talent for volunteer pro bono consultation with the Federal government and other organizations which need the imagination that only speculative writers can provide.

SIGMA members have each committed to consult with Federal authorities for taskings on vital national issues for several days, for travel and lodging expenses only. For extended effort or research, compensation may be based on individual contracts, as appropriate. Current Federal employees may be available on detailee status.

All SIGMA activities are strictly voluntary, and any member can decline any proposed tasking or meeting for any reason, with no further explanation.

Tom was instrumental in starting the fusor movement (home made experimental fusion reactors) due to the encouragement of Dr. Robert Bussard. He also worked with Dr. Bussard on the Polywell Fusion power reactor (no net power though at the size of current experiments). You can read about that effort at: World's Simplest Fusion Reactor Revisited. There are links on the sidebar to the Fusor Consortium and lots of other good stuff.

You can also read a science fiction story Tom wrote on fusion which had its world premiere here in July of 2007. Getting Tuned Up.

Congrats Tom! And with any kind of luck you can help us to deserve the best future we can get, because if we don't deserve it the getting will be much harder.

ITER vs The Stone Axe

Stephen Strauss takes a look at big science and comes away unimpressed. He talks about two exhibits he saw. One for the $15 billion ITER (pronounced EATER - heh) and another about neolithic technology - mat weaving, pottery making, chipping stone axes.

At the recent European Science Open Forum conference in Barcelona, for example, I was strolling through exhibits aimed at — please don't gag — science outreach. The underlying theme of all these displays seemed to me to be: since their schooling actually teaches many ordinary people to be discomforted by — if not to actually fear and loath — science, let's see if we can't do something in these venues to get people to hate science a little bit less.

And why do people hate science so much? Well it is hard to understand and requires a lot of complicated math and difficult concepts. I'm pretty good with that sort of thing. I understand Einstein but the math is beyond me. String Theory? Fuhgeddaboutit. So how about neolithic technology?

Right across from ITER was an exhibit in which a group of paleo-archeologists had set up a display to show the technology of the past in operation. So you had a guy sitting cross-legged, banging away at a rock to make a hand ax. Chip, chip, and chip. You had someone else weaving plants together to make a mat. Weave, weave, and weave. Someone else was taking clay and making a pot. There was no placard asking: Hand axe making, will it always be 40 years away? There were no critics of the effort calling it a huge waste of national resources.

So what does the juxtaposition of the two very different demonstrations of technology tell us about disbelief?

To begin with, the ITER project and all hugely expensive big science efforts — think the International Space Station, think Large Hadron Collider, which recently has received a tonne of press — aren't like making hand axes. I looked at the man diligently chipping away and realized that the price of his failure wasn't very high. So what if it turned out the rock type you made axes from wasn't strong enough to chop wood? You simply went back and made axes from something else until you got an ax that worked.

And you, in this case, would simply be some intrepid carver and not some large part of the Paleolithic science world.

On the other hand, if ITER fails, it is massively unlikely there is going to be another effort to correct its errors. Research on its level is simply too big and expensive and time-consuming. But what if it succeeds — but only kinda? What if its results show that you can produce energy, but that it is 10 time times more expensive than energy from other sources? What if figuring out how to make that equation more favorable will require at least three iterations of ITER?

So how should we be thinking about such projects? A little differently to be sure.

What you put in place with these vastly expensive research efforts is a "can't afford to fail" paradigm. Unlike trying to find the best plant material to weave into a mat, ITER, the Large Hadron Collider, etc., must succeed on first go-round. With ITER, there is no second kind of rock to be chipped away, no other plants to be woven, no different type of clay to be baked into a plate.

And that's what I so disbelieve about it. It's not really experimental science; it's risky, we-can't-fail, all-or-nothing science and I would respond to that paradigm with the wisdom of stone axe makers.

Sometimes your research should be based not on how glorious success might be, but on how little you will have lost if you screw up.

So what should we be doing about fusion? Lots of small "understand the science" and "proof of concept" projects. Say 100 two million dollar efforts. About 10 twenty million dollar efforts based on the successes of the two million dollar jobs. And one or two two hundred million dollar efforts based on the promise of the $20 million efforts. Total cost of around a billion dollars a year when everything is fully ramped up. Nothing that is too big to fail and nothing where testable results are fifteen to thirty years off.

Of course I have my favorites. Here is one that I described in the Fusion Report of 29 August 2008.

Fusion Report 29 August 2008

Alan Boyle has the latest on the EMC2 fusion experiments.

Researchers have finished the first phase of an unorthodox, low-cost nuclear fusion experiment that has generated a megawatt's worth of buzz on the Internet – and they are now waiting for a verdict from their federal funders on whether to proceed to the next phase.

Richard Nebel, leader of the research team at EMC2 Fusion in New Mexico, declined to detail the results of the project, saying that was up to the people paying the bills. But he did said “we have had some success" in the effort to reproduce the promising results reported by the late physicist Robert Bussard.

"It's kind of a mix," he said.

That is a disappointment. However it is not completely negative so maybe further work is warranted.

Nebel said his leave from Los Alamos is due to reach the one-year mark in mid-September, but he doesn't foresee any problem in extending the leave if the second-phase funding comes through. Whether or not the Navy funds the next phase, the past year's effort has been worth it, Nebel said. "We're generally happy with what we've been getting out of it, and we've learned a tremendous amount," he said.

All that learning won't go away. "Regardless of what happens to it, we're going to get this thing well written up and documented," Nebel said.

Getting the experiment's findings down on paper will help the EMC2 team - or future teams of fusion researchers - advance the legacy left behind by Bussard. And that's a fitting tribute to the unconventional physicist as the calendar rolls toward the anniversary of his death.

"Bob Bussard was a truly innovative person, that's abundantly clear," Nebel said. "I hope he will be remembered for that. I think that will be the case."

You will note that yours truly (IEC Fusion Technology blog) got a link from Mr. Boyle. I'm honored. If you haven't seen the material before read the link he gave Tom Ligon. And if you are interested in following the progress to date read Fusion Report 13 June 008 which has links to previous reports.

I can't wait to read the full report.

Math For Plasma Simulation

I have added Math For Plasma Simulation [pdf] to the sidebar under Fusion Reference.

H/T drmike

Update 2317z 30 Jan 2010

Link broken. H/T AC via e-mail for the notification and the current correct link.

Magnetic Field Measurement

Electronic Design News [pdf] has an overview of instruments and technologies for measuring magnetic fields.

A Certain Reality

"As far as the laws of mathematics refer to reality, they are not certain; as far as they are certain, they do not refer to reality."--Albert Einstein

"If we knew what it was we were doing, it would not be called research, would it?" - Albert Einstein

Critics

Critics are a very valuable resource if the criticism is based on reason. All designs should be thoroughly reviewed by their harshest reasonable critic. You get better designs that way. Or you kill bad investments before they get too big.

I have to say that right now just from an engineering perspective (assuming the physics works) the challenges of building a 100 MWth BFR are daunting. Not all of them have answers at this time.

Students Achieve Fusion

Students at Penninsula College have achieved fusion. I am more than a little proud to say I had a little to do with it. At least in so far as getting them on the right track.


From left to right: Devon, Ivan, Sarah, Chris, Aaron, and Derek.


The Reactor


It glows

Which just goes to show that fusion research need not take big labs and big budgets. There is a lot that can be done in small labs to advance the state of the art. So let me encourage the rest of you: Start A Fusion Program In Your Own Home Town. America needs your help. The world needs your help.

Let me add that the genesis of this report was a bit done by ClassicPenny at Talk Polywell

You Have To Be A Little Crazy

Innovate Like Edison is a book about how to use Edison's system of innovation to improve business practices. Control Engineering discusses the book based on a talk given at the recent Society for Manufacturing Engineers Convention in Detroit, MI.

Detroit, MI – Understanding Thomas Edison’s patterns of thinking can help us be more like the guy who has 1,093 U.S. patents to his name, says co-author of the book, “Innovate Like Edison: The Success System of America’s Greatest Inventor.” Sarah Miller Caldicott, also Edison’s great grandniece, helped a packed room of engineers at the SME Annual Meeting gain insights into Edison’s thought patterns, to improve U.S. competitiveness.

Bearing a family resemblance to her great great Aunt Mina Miller – who married Edison in 1886 – and telling stories of growing up with Edison phonographs in her bedroom, Caldicott offered exercises which seemed to win over SME attendees... along with a promise of an autographed book.

Caldicott, also founder of The Power Patterns of Innovation, noted five best practices based on her 3-year study of Edison: a solution-centered mindset; kaleidoscopic thinking; full-spectrum engagement; master-mind collaboration; and super value creation.

All the points are covered in the review, but I'd like to take up this one:

-Cultivate a solution-centered mindset. Do not seize an answer at the beginning of an initiative. A framework of options and pathways can lead to solutions. Look outward and scan the environment. Lean ahead and hunt for a solution. Combine factual information with what-if or if-then thinking. Envision the solution and “emotionalize” the state that will be experienced upon getting there.

Which could be translated into be patiently crazy. Also note that emotion is considered an important part of rational thinking. In fact emotion may be one of the most critical feedback mechanisms. We have a very good pattern recognition system in our brains. If you train your brain with good patterns, after a while you get a "feel" about the right way and the wrong way to do things. Caldicott also goes into the need for thinking before acting. She even calls it contemplation. Be quiet. Sit Still. Shut up. And good preparation for that contemplation time is to get on the www and start looking around. Go deep. Some times the good stuff is on the 30th page of a search.

I always had a standard which I tried to stick to when it came to development: Five days of planning, two days of work. That is both imperative and descriptive. You must recognize that this method is scary for most management. The typical exhortation is: put in all the time you need to, but meet the schedule. My answer was: I'm not putting in any extra time. I will meet your schedule. In two days I will have a plan. How did that work out? Three months were alloted to get the project on track. I did it in five weeks. Without raising a sweat. Of course once you have proven yourself it is easier the next time.

Some Objections - Some Answers

Art Carlson, who was commenting on an Alan Boyle article about the progress the EMC2 team was making with the Bussard Fusion Reactor tests, had some objections to the whole concept.

It's fun to daydream, isn't it? And it's easy, too, as long as you don't know too much.

There's more reasons than you can shake a stick at that this won't work. For starters, you can forget about aneutronic fusion. It's not just the temperature, Bremstrahlung is almost to certain radiate more energy than you produce by fusion no matter how good your confinement is. Even if you somehow manage to get a decent power balance, for a given plasma pressure and fusion power, a p-B11 reactor would have to be about 1000 times bigger (and more expensive) than a corresponding D-T reactor.

The next thing to worry about is the electrons. The magnetic configuration has not only lines of radial field from the center to the edge, which is bad enough judging from the experience with mirror machines, it also has lines of *zero* field along which the electrons will gush out. The idea of recycling electrons lost through the cusps won't work because they will come out almost parallel to the field but hit the return cusp with a large perpendicular velocity component they picked up going around the bend.

And the ions? The device is conceived to utilize a bi-modal velocity distribution, which will be destroyed very quickly by the two-stream instability. The anisotropy of the velocity distribution is also know to be a big problem, again from experience in the mirror program.

We haven't even started to talk about energy loss to the grids, the consequences of tiny field misalignments, charge-exchange ion losses, energy coupling between electrons and ions, and whether the potential distribution envisioned is even possible at a non-trivial ion density.

Since they managed to sweet talk somebody into giving them money, let them finish and publish their results, but let's not stop looking for ways to save energy and trying to develop other, less sexy but more reliable energy sources.

Art Carlson, Munich, Germany (Sent Friday, June 13, 2008 1:17 PM)

rnebel who is conducting the test and is definitely not day dreaming had a response.

Just a few comments for Mr. Carlson

1. The theory says that you can beat Bremstrahlung, but it's a challenge. The key is to keep the Boron concentration low compared the proton concentration so Z isn’t too bad. You pay for it in power density, but there is an optimum which works. You also gain because the electron energies are low in the high density regions.

2. The size arguments apply for machines where confinement is limited by cross-field diffusion like Tokamaks. They don't apply for electrostatic machines.

3. The Polywell doesn't have any lines of zero field. Take a look at the original papers on the configuration. See :
Bussard R.W., FusionTechnology, Vol. 19, 273, (1991) .
or
Krall N.A., Fusion Technology. Vol. 22, 42 (1992).

Furthermore, one expects adiabatic behavior along the field lines external to the device. Thus, what goes out comes back in. Phase space scattering is small because the density is small external to the device.

4. The machine does not use a bi-modal velocity distribution. We have looked at two-stream in detail, and it is not an issue for this machine. The most definitive treatise on the ions is : L. Chacon, G. H. Miley, D. C. Barnes, D. A. Knoll, Phys. Plasmas 7, 4547 (2000) which concluded partially relaxed ion distributions work just fine. Furthermore, the Polywell doesn’t even require ion convergence to work (unlike most other electrostatic devices). It helps, but it isn’t a requirement.

5. The system doesn’t have grids. It has magnetically insulated coil cases to provide the electrostatic acceleration. That’s what keeps the losses tolerable.

6. The electrostatic potential well is an issue. Maintaining it depends on the detailed particle balance. The “knobs” that affect it are the electron confinement time, the ion confinement time, and the electron injection current. There are methods of controlling all of these knobs.

rnebel (Sent Friday, June 13, 2008 6:17 PM)

One must be wary of a certain kind of dreamer:

All men dream, but not equally. Those who dream by night in the dusty recesses of their minds wake in the day to find that it was vanity: but the dreamers of the day are dangerous men, for they may act their dream with open eyes, to make it possible.

—T. E. Lawrence from "Seven Pillars of Wisdom"

Fusion Report 13 June 008

Alan Boyle has a new report on the goings on in New Mexico at EMC2 Fusion Labs.

Emc2 Fusion's Richard Nebel can't say yet whether his team's garage-shop plasma experiment will lead to cheap, abundant fusion power. But he can say that after months of tweaking, the WB-7 device "runs like a top" - and he's hoping to get definitive answers about a technology that has tantalized grass-roots fusion fans for years.

Dr Nebel has been rather quiet lately in the usual forum he frequents, so this update is very welcome to all us grass-roots fusion fans.

"We're kind of a combination of high tech and Home Depot, because a lot of this stuff we make ourselves," Nebel told me today. "We're operating out of a glorified garage, but it's appropriate for what we're doing."

The Emc2 team has been ramping up its tests over the past few months, with the aim of using WB-7 to verify Bussard's WB-6 results. Today, Nebel said he's confident that the answers will be forthcoming, one way or the other.

"We're fully operational and we're getting data," Nebel said. "The machine runs like a top. You can just sit there and take data all afternoon."

Now compare "We're operating out of a glorified garage... with ITER's 30 % cost over run so far.

an independent panel of experts will be coming to Santa Fe this summer to review the WB-7 experiment, Nebel said.

"We're going to show them the whole thing, warts and all," he said.

Because of the complexity, it will take some interpretation to determine exactly how the experiment is turning out. "The answers are going to be kind of nuanced," Nebel said.

The experts' assessment will feed into the decision on whether to move forward with larger-scale tests. Nebel said he won't discuss the data publicly until his funders have made that decision.

"Warts and all now isn't that refreshing.

Nebel may be low-key about the experiment, but he has high hopes for Bussard's Polywell fusion concept. If it works the way Nebel hopes, the system could open the way for larger-scale, commercially viable fusion reactors and even new types of space propulsion systems.

"We're looking at power generation with this machine," Nebel said. "This machine is so inexpensive going into the 100-megawatt range that there's no compelling reason for not just doing it. We're trying to take bigger steps than you would with a conventional fusion machine."

With my typical engineering sensibilities I still think some intermediate steps would be required. Like a continuously operating experiment. It need not be a very big machine but it will require a big power supply. It might need to draw 4 to 6 MW on start up. In fact it might need that for the whole duration of operation. The machine scales in a funny way. Coil power (for a copper coil demo) goes up as the reactor gets large but the accelerator power goes down.

Over the next decade, billions of dollars are due to be spent on the most conventional approach to nuclear fusion, which is based on a magnetic confinement device known as a tokamak. The $13 billion ITER experimental plasma project is just starting to take shape in France, and there's already talk that bigger budgets and longer timetables will be required.

If the Polywell system's worth is proven, that could provide a cheaper, faster route to the same goal - and that's why there's a groundswell of grass-roots interest in Nebel's progress. What's more, a large-scale Polywell device could use cleaner fusion fuels - for example, lunar helium-3, or hydrogen and boron ions. Nebel eventually hopes to make use of the hydrogen-boron combination, known as pB11 fusion.

"The reason that advanced fuels are so hard for conventional fusion machines is that you have to go to high temperatures," Nebel explained. "High temperatures are difficult on a conventional fusion machine. ... If you look at electrostatics, high temperatures aren't hard. High temperatures are high voltage."

Most researchers would see conventional tokamak machines as the safer route to commercial fusion power. There's a chance that Bussard's Polywell dream will prove illusory, due to scientific or engineering bugaboos yet to be revealed. But even though Nebel can't yet talk about the data, he's proud that he and his colleagues at Emc2 have gotten so far so quickly.

"By God, we built a laboratory and an experiment in nine months," he said, "and we're getting data out of it."

By God I hope it works out.

If you want to know what you can do to help have a look at Starting A Fusion Program In Your Home Town.

H/T Instapundit

Literate Programming

Literate Programming

Donald Knuth. "Literate Programming (1984)" in Literate Programming. CSLI, 1992, pg. 99.

I believe that the time is ripe for significantly better documentation of programs, and that we can best achieve this by considering programs to be works of literature. Hence, my title: "Literate Programming."

Let us change our traditional attitude to the construction of programs: Instead of imagining that our main task is to instruct a computer what to do, let us concentrate rather on explaining to human beings what we want a computer to do.

The practitioner of literate programming can be regarded as an essayist, whose main concern is with exposition and excellence of style. Such an author, with thesaurus in hand, chooses the names of variables carefully and explains what each variable means. He or she strives for a program that is comprehensible because its concepts have been introduced in an order that is best for human understanding, using a mixture of formal and informal methods that reinforce each other.

I have always programmed like that once I started writing professionally in Forth. Leo Brodie's book Thinking FORTH [free download] was all about using the literate style. The most important thing after Naming the Parts is good factoring.

CAN Bus And System Control

I like CAN (Controller Area Network) Bus for control systems. It has moderate speed (1 Mbs), it is deterministic., it has priority control for multi-master operation, and because of its use in autos it is robust and low cost. In addition it has been on the market for about 10 years so it is well established with lots of vendors to choose from. In addition there are a number of MCUs with built in CAN.

For test reactor operation I see a hierarchy of CAN buses, each devoted to a given function and then all melded into a master bus. Let me start with the sub nets.

1. Vacuum Gauge/Vacuum Pump Control Bus
2. HV Power Supply Internal Buses
3. Instrumentation Buses (Temp Monitoring, Flow Monitoring, Master Clock, Neutron Counter, Electrical Power Measurement and Control, etc.)
4. Auxiliary Control (Electrical Power Measurement and Control, etc.)

And then a master bus to send messages to/from the sub buses.

I haven't decided on an MCU yet. One of the requirements would be that it is FLASH programmable and have a built in CAN bus. I have been thinking about pressure measurement lately so I'd like to lay out what a CAN bus interface would look like.

The pressure transducers I have in mind (MKS 722 and MKS 626A) have a 0 to 10 V output. I haven't picked any other components yet. So we will just look at functions.

1. Pressure (dependent on transducer - from 1000 torr to .1 torr full scale, 17 bits)
2. Board temperature (0 to 100 deg C, nominal 30 deg C 10 bits nominal - 8 actual)
3. Board power bus voltage (20 to 60V, nominal 48VDC, 10 bits nominal - 8 actual)
4. Board power bus current (0 to 255 mA, nominal TBD, 10 bits nominal - 8 actual)
5. Various internal power supplies (TBD, TBD, 10 bits nominal - 8 actual)
6. Isolated CAN supply, Isolated Pressure transducer supply, Isolated MCU supplies.

Lets start with the transducer front end. It should have an op-amp (fully differential).

For the 24 bit converter I like the AD7767 it has an accuracy of 17 bits which matches the one part in 1e5 resolution of the pressure transducer.

The ADA4941-1 is a nice companion amplifier. And the ADR425 looks like a nice reference. Good specs, not too expensive.

That covers the main parts of the analog side. What about the computing side? I have been looking around and I think I like the Fujitsu CAN bus microprocessors the best. Its architecture is a mixture of a FORTH engine and a Z8 register bank.


Fujitsu 16 bit microcontrollers

Fujitsu 32 bit microcontrollers

Fujitsu microcontrollers

I haven't addressed the CAN interface yet. It is pretty simple: a few high speed optocouplers, a bus driver chip, a separate isolated power supply, some protection components and away we go.

Let me add that Fujitsu has 8 bitters that I have yet to take a serious look at. I'll probably remedy that in the next few days.

The Atmel CAN processors would be a good second choice. The reason I like the Fujitsu stuff better is that it has a very good migration path and I'd like to use one software model for as many of the process tasks as possible.


I also like the Infineon TC1166 32 bit processor with CAN. Digikey sells them for about $39 ea. Quantity one. Since programming and hardware design is going to be the big cost for the initial units I'm going to do what Chuck Moore suggests. Get the biggest fastest processor you can afford to start. Then reduce the foot print if volumes warrant.

The Fujitsu part is more open ended and has a very simple CALL structure. However, there are no automatic register saves with calls. Thus every CALL must have at least one PUSH and one POP if you expect nested calls. The Infineon has a more definite programming model with user space registers and system space registers. They each save registers on a CALL (but different sets). The cost is 2 to 5 clocks. Not a big hit (but they could have done better). The Infineon part also seems like it might be harder to learn due to instruction pipeline flushing requirements in some situations that require an instruction to finish before the following instruction(s) are executed. I do like the floating point and some other features of the Infineon, but I will set it aside for now. Well I read on and find that the Fujitsu Part also has a 5 deep pipeline. I guess when you need to flush it you just do a bunch of no-ops.

The Fujitsu also is more deterministic and can do tail end recursion since the pipeline is only one level deep (actually it is five deep also but it can do tail end recursion.). However the divide routines are not as mechanized as they are in the Infineon. Since I hardly ever use them except with user input to precalculate multiply constants that is not such a big hit.

Update 09 Jun 1534z

I have been looking at the Freescale MPC551x MPUs. I like them. Plus Freescale gives away an assembler good enough to get a FORTH up on the chip.

I like the Atmel ATA6660 CAN bus physical interface. There are later and greater chips out with more functionality , however I like to keep the interface simple and electrically isolated. You can do that with three high speed optocouplers and an isolation supply. A 48 V to 5 V job at about 1 W would be good.

FORTH Is Back

The FORTH programming system is one of my favorites. The language is simple, compact, and extremely powerful, and almost dead. It has been kept alive over the years by a few fanatics including myself. Well, it looks like it is coming back in a big way. A lot of big names are now into the game.

By INQUIRER staff: Friday, 07 December 2007, 2:40 PM

PATRIOT SCIENTIFIC, which jointly owns a microprocessor related patent porfolio, said that Taiwanese firm Lite-On has bought a licence, becoming the third firm in a week to do so.

According to the firm, it's the first Taiwanese system company to buy a licence. Daewoo and a US manufacturer said they'd buy a licence earlier this week.

The firm's "Moore Microprocessor Patent Portfolio" that holds IP including seven US patents covering microprocessors, system on chip stuff, and microcontrollers.

This lot have also signed up for licences already. AMD, Intel, Hewlett Packard, Casio, Fujitsu, Sony, Nikon, Seiko Epson, Pentax, Olympus, Kenwood, Agilent, Lexmark, Schneider Electric, NEC Corporation, Funai Electric, Sandisk, Sharp Corporation, Nokia, Bull, Lego, DMP Electronics, Denso Wave, Philips, TEAC, Daewoo Electronics. And now Lite-On.

Now that looks like a rush. Why? Well, a dual stack architecture is pretty well fitted to C. Although C is no near as efficient as FORTH with such an architecture. EE Times Asia has more on the story.

06 Mar 2006

Alliacense announced that Fujitsu Ltd has licensed its intellectual property protected by the Moore Microprocessor Patent (MMP) portfolio. Alliacense is the subsidiary created last year to administer the portfolio on behalf of owners Patriot Scientific Corp. and TPL Group Financial terms of the licensing arrangement were not disclosed.

Fujitsu becomes the third system manufacturer to publicly disclose licensing of the MMP portfolio, following Hewlett-Packard (HP) in January and Casio Computer Co. Ltd last week. In announcing the Casio deal last week, Patriot Scientific revealed that semiconductor makers like Intel Corp. and Advanced Micro Devices (AMD) are not being required to pay royalties on MMP licenses.

Note the earlier date. About a year and a half before the Dec 007 announcement. Also note that I have a friend who works for the TPL Group. I'll have to ask him what happened.

In any case a little more background from the March 006 article:

Patriot and TPL came together in June 2005 to settle a long-standing patent dispute so they could jointly pursue licensing revenue from third parties. The TPL Group has been granted full responsibility and authority for the commercialization and licensing of a unified portfolio of 10 patents.

The MMP portfolio is named after inventor Charles H. Moore, chief technology officer of TPL Group, who is known for inventing the Forth software programming language and for his work in the 1980s on stack-based microprocessors.

It looks like FORTH as a chip architecture is back big time. I wonder if the language will come back as well.

In any case I really like the Fujitsu 16 bit and the Fujitsu 32 bit versions of the architecture.

The Infineon TC1166 32 bit processor looks nice. Digikey sells them for about $39 ea. Quantity one. Since programming and hardware design is going to be the big cost for the initial units I'm going to do what Chuck Moore suggests. Get the biggest fastest processor you can afford to start. Then reduce the foot print if volumes warrant.

Gauging With Intent

We are going to have to read pressures both for experimental purposes and to decide when to turn pumps off and on. Of course first start with minimalist education available on page 7 of this [pdf]. The first critical piece of data is that only capacitance gauges are gas independent. The second critical bit is that the output is linear with pressure and they can cover a 10,000 to 1 pressure range. i.e. 1 millivolt to 10 Volt output.

The Adixen Capacitance Vacuum Gauges come in four models.

1100 to 1e-1 torr
110 to 1e-2 torr
11 to 1e-3 torr
1.1 to 1e-4 torr

Two is probably the minimum for a system. One (1100 torr to 1e-1 torr) to monitor the backing pump inlet pressure. Plus one other chosen for the chamber operating pressure. The 110 to 1e-1 torr model would be good for most current fusor experiments. The minimum output to realize the inherent accuracy of the instruments is around 20 to 50 mV.

Here are some more capacitance gauges.

MKS 722 which has some really nice specs but only comes in a KF 16 flange. Which means an adapter. It covers the 1 torr to 1000 torr full scale range. Around $900 with flange mount. Add about $100 for a flange adapter.

MKS 626A can be ordered with a CF40 (2 3/4") flange. Full scale ranges from .1 torr to 1,000 torr. Around $950 with flange mount.

What if you want to go to lower pressures? I'll go into that in another post.

Fusor Vacuum Pump Choice

I have been neglecting general education on vacuum pumps. So here is Technical Notes on Various Vacuum Pump Types. And of course the wiki on Vacuum Pumps. All for the purpose:

I'm trying to decide on a vacuum pump set up and have come up with two candidates based on their compression ratios for H2:

Adixen ATH31+. 1E11 N2, 1E5 H2 Compression Ratio
Aprox Prices:about $4,700 pump, about $1,700 controller, about $600 required accessories. 4 1/2" CF High Vacuum connection.

Pfeiffer TMU 071YP >1E11 N2, 1E5 H2 Compression Ratio
Aprox Pricesabout $5,200 pump, about $1,300 controller. 4 1/2" CF High Vacuum connection.

	l/s	CR	TU	Wt	IF	OF	FP	FPS	$Pmp	$Cnt
ATH 31+	14	1e5	5e-10	2.7	4.5" CF	KF16	45	1	$4,700	$1700
TMH071P	42	1e5	5e-10	8.4	4.5" CF	KF16	18	2.5	$5,208	$1,298

Abreviations:
l/s = Pump Speed in liters per second For H2
CR = Compression Ratio H2
TU = Ultimate pressure in mbar
Wt = weight lbs
IF = Input (High Vacuum) Flange
OF = Output (Fore Pump) Flange
FP = Max Foreline Pressure mbar
FPS = Min Foreline Pump Speed m^3/hr
$Pmp = Cost of the Pump
$Cnt = Cost of the Controller

The Pfeiffer looks like a better pump for the money. A lot will depend on the fore pump. I'm leaning to a roots blower or some other oil less type pump. So let us look at some. First some education: Scroll vs Rotary Lobe Pumps.

IDP-3, technical [pdf], dry scroll, 3 m³/hr rate, 2.5e-1 torr. ultimate, $2,650

ACP15, technical [pdf], rotary lobe, 14 m³/hr rate, 3.8e-2 torr. ultimate, $5,134

1 torr = 1.33 mbar

Vacuum Flanges

DN	NW	Tube ID. mm	CF Flange O.D. mm	CF Flange O.D. (inches)
DN16	16	16	34	1 1/3"
DN25	25	22	-54	(2 1/8")
DN40	35	35	70	2 3/4"
DN50	50	47	-86	(3 3/8")
DN63	63	57	114	4 1/2"
DN100	100	98	150	6"
DN150	150	146	203	8"
DN200	200	197	254	10"

Taken from 5Pascal [pdf]

Fusor Vacuum Pumps

I'm going to start with turbo pumps and then add roughing pumps later. I'm going to add some compression ratio numbers which will determine final pressure. Plus prices for pumps and controllers if I can find them.

Adixen ATH31+. 1E11 N2, 1E5 H2 Compression Ratio
Aprox Prices:about $4,700 pump, about $1,700 controller, about $600 required accessories. 4 1/2" CF High Vacuum connection.

Varian Turbo V81M. 5E8 N2, 7E3 H2 Compression Ratio
Aprox Prices $5,900 Pump + Controller. CF 63 High Vacuum connection

Pfeiffer TMU 071YP >1E11 N2, 1E5 H2 Compression Ratio
Aprox Pricesabout $4,700 pump, about $1,200 controller,

Oerlikon Leybold TURBOVAC 50 2E6 N2 Compression Ratio
Aprox Prices:about $3,300 pump, about $1,500 controller. CF 63 High Vacuum connection

Fusor Power Supplies

I think a supply in the 15KV to 30KV range with an available current of 30 mA would be good for general purpose experimentation and neutron generation. It should be adjustable, regulated, and current limited. It should be immune to the usual lab accidents such as shorts and current bursts. It should have an emergency fast trip.

I have some candidate mfgrs:

Glassman High Voltage Inc.
Spellman High Voltage
Universal Voltronics

Fusor Vacuum Vessel

The Kimball Physics spherical cube and expanded spherical cube seem like very good designs for the project and the price is right.

I like the 4.8", 6.5" and 8.4" sizes. The prices run from $1,700 to $9,600 depending on size and features desired.

Here is what I think are useful sizes and prices:

MCF450-SC60000 4.8" ID; 57.91 cu inches, .95 liter Volume; 6 - 4 1/2" CF (DN63) Vacuum Ports; $1,700

MCF450-ESC60800 6.5" ID; 143.79 cu inches 2.36 liter Volume; 6 - 4 1/2" CF (DN63), 8 - 2 3/4 CF (DN40) Vacuum Ports; $3,550

MCF600-ESC600000 8.4" ID; 310.34 cu inches 5.09 liter Volume; 6 - 6" CF (DN63) Vacuum Ports; $6,800

Boron Vapor Pressure

This question of Boron vapor pressure has come up a number of times in various discussions so I think a reference post is a good idea.

From Boron Properties:

Vapor Pressure: 4.6 x 10-4 to 8.5 x 10-3 mm @2200K

From Boron - Yahoo Answers:

Temperature/Vapor pressure:

2348K 1 Pa
2562K 10 Pa
2822K 100 Pa
3141K 1 k Pa
3545K 10 k Pa
4072K 100 k Pa

Constructing a Fusor - Joseph Zambelli

Joseph Zambelli has built a fusor. He starts out with a very nice picture of his device.

This Inertial Electrostatic Confinement Fusion (IECF) fast neutron generator is a complete, easy-to-operate tabletop system. As presently configured, it produces up to 6.75E5 2.5 MeV neutrons per second with an acceleration voltage of 42 KV and a current of 18mA, at a pressure of 11.5 mTorr, with a start-up time of 10 minutes or less. It can easily be upgraded to yield even higher neutron production rates if so desired. This design has extremely low operational costs, and requires only a single 120V outlet for power. It features an 8” UHV Stainless Steel spherical, multi-port chamber evacuated with turbo-drag and rotary backing pumps.

He has another picture and link page here. The link page has links to the following the following sections:

Theory
Construction
Operation
Demonstration System
Further Links

Constructing a Fusor - Longwood University

I just came across this interesting report on the construction of a Farnsworth Fusor by Andrew Grzankowski at Longwood University, Farmville, Virginia.

Over the Summer of 2007, physics major Andrew Grzankowski worked with Longwood faculty member Keith Rider (Chemistry) to construct a Farnsworth Fusion Reactor. Here’s a breakdown of the project.

In the end notes there are a series of links which I am going to reproduce here.

Fusor.net

Original patents (H-M Fusor)[pdf]

Thesis – Carl Dietrich 2007 (MIT)[pdf]

Tom Ligon – The world’s simplest fusion reactor, and how to make it work[pdf]

Todd Rider – Is there a better route to fusion? (MIT)[pdf]

Prof. Kim Molvig – Fusion without neutrons using p-B11 (MIT Fusion Seminar)[pdf]

EMC2 Fusion Development Corp. – Inertial Electrodynamic Fusion: The answer to interplanetary space travel? - Tom Ligon's Presentation, 26th International Space Development Conference, May 2007 [ppt]

Small Vacuum Vessel Suppliers

Here is a handy list of vacuum vessel suppliers suitable for Fusor Construction. I will be adding to the list from time to time.

Meyer Tool and Manufacturing Oak Lawn, Illinois

Kimball Physics Wilton, New Hampshire

Kurt J. Lesker Company Clairton, PA

MDC Vacuum Products, LLC Hayward, California

Nor-Cal Products Yreka, CA

Trinos Vacuum Systems, Inc. Chicago, Illinois

A&N Corporation Williston, FL

Atlas Technologies Port Townsend WA

Sci Quip - Used Eqpt.

Oerlikon Leybold Flanges and Fittings

Link Added To Sidebar

I have added IEC Fusion Web Ring to the sidebar. It links to amateur fusion efforts.

Fusion Report 15 May 008

In Picture Of WB-7 Bussard Fusion Test Reactor Available I reported that there was a picture of the WB-7 Fusion Test Reactor available. (Well duh). I must sadly report that it is no longer available. Instead EMC2 Fusion has replaced it with a picture of a plasma test of the fusion reactor using Helium gas. Yeah! We are another small step on the way to fusion power. Or to proving you can't get there from here. Depending.

Reactor Size

I was rereading Sekora's paper on POPS [pdf] and came across this gem.

It is very difficult to achieve field strength approximately 50-100 kV/cm without causing arcing.The maximum field strength is governed by the Paschen curve.

So let us look at what a decelerator BFR might look like. Reaction volume 1 meter radius. That is a given. Let us assume 200 KV drive voltage. If we assume a voltage of 20KV/cm that gives 10 cm to zero voltage. Then assume 2 MV decelerator voltage. That is 1 meter. So the total radius is 2.1 meter. At 40" per meter (roughly) That is 84" radius or 168" diameter. About 14 ft in diameter for a 100 MWth reactor. Suppose we go to 40KV/cm (about the limit). That would be 1 meter reaction space. About 5 cm to zero voltage. And 50 cm for the decelerator. That would be 1.55 m radius. 3.1 m diameter. About 124" or a little over 10 ft in diameter. So odds are the reactor will be between 10 ft and 15 ft in diameter for a design with direct energy conversion. That would fit on all but the smallest ships.

Standardizing Fusion Test Reactors

In my recent post Starting A Fusion Program In Your Home Town I talked about expanding the fusion design and testing environment to increase the rate of progress in the development of a power producing reactor.

The lead Bussard Fusion Reactor (BFR) experimenter, rnebel, has read that article and has chimed in here with his thoughts.

One of the things we have been considering is selling a "turnkey" version of the WB-7. In this case we would design, build, license and deliver an operating Polywell, probably on the scale of the present machine. Operator training and tech support would also be part of the deal. The model is to use a plug and play concept where the user could substitute their own parts (electron sources, for instance) in an open architecture system. This is similar to what IBM did with the PC in the early 80s. It would give people who are interested in Polywells a chance to develop their own new patentable concepts and new companies without having to go through the entire learning curve that we have been on for the past several years. This struck us as a way to jumpstart the industry and get a lot of new ideas and people involved in Polywells. These devices could be funded through government grants (we have found a mechanism) or privately. I think we could do a turnkey machine for a ~ $500k-$1000k depending on how many people are interested. The idea would be for the government to make grants to institutions and then we would be able to competitively bid on providing the hardware. Ideally, I would like to see at least one Polywell in every Congressional district in the US. Since the cost is cheap, this is a tractable. Is this something you might be interested in?

My reply went as follows:

Sign me up.

I think it might also be useful to do a $10K to $100K fusor type device for those on a more limited budget. Jr. Colleges etc. There is a lot that can be learned from such a device that would help with more efficient (Pollywell) devices.

BTW in other places (fusor forum) I have made the evolution of the computer hobby argument.

Great minds etc.

Also a range of devices and power supplies. i.e. 25KV, 50KV and 100KV pulsed supplies. Then the same range of continuous operation supplies. Same for the reactors. Pulsed and continuous operation. The equipment should be standardized as much as possible - at least for the starter kits so we could get the efficiencies of mass production. Also standardized test equipment. Standardized control.

If we had 435 tests going on at once in each district that would cause the Congress critters to all get behind the fusion push. Very astute. That was sort of my idea.

Again - contact me and tell me how I can help. I'm rarin' to go.

Simon

Any venture capital people who would like to start something - contact me.

Reaction Rate and Drive Voltage Spread Sheet

You can down load it at Reaction Rate and Drive Voltage.

Starting A Fusion Program In Your Home Town

It is getting to the point that to make advances in the field of IEC Fusion collaborative efforts will be required due to the range of knowledge required and the cost. The individual with the home built fusor is not a thing of the past by any means, but it is not the wave of the future. I have been contacted by people from Jr. Colleges who are interested in doing fusion research so that is probably the place to go. Get your local Jr. College or College interested.

Here is one College doing work in the field that I have provided some advice and direction to: Peninsula College Fusion experiments. Here is another link with more details to the Peninsula College Fusor Project. There is also this link describing the genesis of the project, the cost in materials ($3,000), and the educational benefits. They also have a very nice Resources Link page.

In that vein I have contacted Rock Valley College and Rockford College (in Rockford, Illinois) to see if I couldn't get something started. We shall see if anything comes of it.

Here are some links to get those interested started:

IEC Fusion Technology blog
Open Source Fusor Research Consortium II
The World's Simplest Fusion Reactor Revisited
Disciplines and areas touched upon in fusor construction

Standardized Fusion Test Reactors.

I'm going to add a list of Colleges and Universities that are working on small fusion (budgets under $100,000 - places like The University of Wisconsin at Madison which has a rather well funded IEC program - well above $100,000 - will not be on the list). If you get something going in your home town send me some info. I'll add you to the list.

UMass Lowell.
A Community College - no name given

Fusion Report 06 May 008

Richard Nebel tells about plans for commercializing the Bussard Fusion Reactor (BFR) at Talk Polywell. Richard starts off discussing who owns the BFR technology and patents. DOD is The Department of Defense. Currently the US Navy is funding the research.

...EMC2 owns the patents and the commercialization rights. DOD retains the right to use the technology free of charge. That's a pretty standard arrangement.

As for DOD taking control of the technology, I think that's pretty unlikely. The most similar parallel to this that I can think of was the development of fission power. Both nuclear fission propulsion and commercial power were developed in parallel. It isn't a coincidence that both systems are LWRs. I expect a similar situation here. Everyone that I have talked to at the DOD understands that energy supply is a major national security issue. It's not in the national interest of the US to keep this technology from going commercial. Furthermore, this project has never been classified. Fusion research world-wide was declassified in 1958 by international treaty.

Finally, I appreciate your concern about research being slowed down by the lack of dialogue. My previous research at LANL (POPS for instance) was always public domain. The reason we did it that way is because we figured that the patents would run out before we could commercialize it and the benefits of having it critiqued outweighed the drawbacks of getting "scooped". I still feel that way, but I have a little different responsibilities at EMC2. We have a responsibility to get this technology developed in a timely manner and I also have a responsibility to look after the interests of our employees and the corporation.

From the way he is talking he seems pretty confidant of success. I sure hope he is right. Dr. Nebel also reports that the EMC2 contract with the Navy runs through August. So that gives some idea of when we might know the answer.

To get an idea of what success would mean check out:

Easy Low Cost No Radiation Fusion also check out the IEC Fusion Technology blog.

The side bar at IEC Fusion Technology blog has links to various discussion groups. They can be found under the heading Working Groups.

A good tutorial and a history of the project before the US Navy resumed funding can be found at: World's Simplest Fusion Reactor Revisited.

Fusion Report 05 May 008

Richard Nebel reports at Talk Polywell that the EMC2 contract with the Navy runs through August.

Fusion Report 02 May 008

Here is a progress report from MSNBC's Cosmic Log about the status of the Bussard Fusion Experiment, WB-7.

Currently, the most promising path toward electrostatic fusion runs through Santa Fe, N.M., where a team at EMC2 Fusion Development Corp. is currently trying to validate Bussard's results. The team's leader, Richard Nebel, told me this week that it's still too early to gauge how promising the Bussard fusion device could be.

"We're getting high-power plasma," he said. "We don't have answers ... [but] we're far enough along that we know we're going to get answers."

If you want to learn more about Bussard's IEC Fusion here is a good place to go:

Easy Low Cost No Radiation Fusion

The side bar here has links to various discussion groups. They can be found under the heading Working Groups. You might be especially interested in the Talk Polywell discussion group where Richard Nebel can often be found commenting and answering questions.

The World's Simplest Fusion Reactor Revisited

Tom has graciously provided a pdf of his most recent Analog article The World’s Simplest Fusion Reactor Revisited for your edification and enjoyment. Please read the following and then click on the link provided for your own copy. Tom sends his regards to all. Enjoy!

Copyright 2007, 2008, by Tom Ligon. This article was first published in the January- February 2008 edition of Analog Science Fiction and Fact. Special edition with postscript for iecfusiontech.blogspot.com and fusor.net. This document may be downloaded, printed out, or linked from other sites, but please do not re-post it on other websites, or re-publish it, without the author’s permission. If corrections or updates are needed, I’d like a limited number of copies to track down.

The World’s Simplest Fusion Reactor Revisited

For All Mankind

A lot of people have been asking me publicly and privately, if the Bussard Fusion Technology is successful, can it be bottled up by special interests? I think the we have an answer from Dr. Richard Nebel who is now running the experiments in New Mexico.

Your concern is something that EMC2 has thought about. The Polywell is what is generally described as a "disruptive technology". Namely, it is a technological surprise that changes everything. A lot of people have/are investing a lot of money in energy technologies. The Polywell is their worst nightmare. Consider for a moment who isn't going to like the Polywell:

1. The fusion people. They've already gone ballistic (but we're not going to go there).
2. The fission people. They're working on a "nuclear renaissance".
3. The solar people.
4. The wind people.
5. Big oil.
6. The gas and coal companies
7. The biofuels people.
8. A few of the environmentalists.

As you can see, we are pretty much an equal opportunity irritant. We are very well aware that any number of people would like to sit on this technology and keep it out of the market. This is one of the primary reasons that Dr. Bussard chose to have this project funded by the Navy rather than privately funded (where we probably would have had a much easier schedule). With the Navy contract, we retain the rights to the intellectual property for commercialization.

Dr. Bussards's desires for this technology were very clear: he wanted it developed and used by the public ASAP. We intend to honor those wishes.

Dr. Nebel, if the latest experiment (WB-7) works out and you read this, I want you to know that if you can use my help I'm good to go. I'm willing to sweep the floors if that is the way you think you can best use me.

Cross Posted at Power and Control

Picture Of WB-7 Fusion Test Reactor Available

There is a picture up at EMC2 Fusion showing the WB-7 Test Reactor vessel. All polished stainless steel with a nice logo.

H/T Tom Ligon

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I do believe plasma physics has gone astray by the unfortunate use of the term instability to describe how a plasma reacts on itself. I think the term reaction would help to open up people's mindset. A plasma is not a stable thing. It reacts to everything including itself.

Plasma kinking is not an instability, plasma kinking is a reaction.

LC POPS

A resonant circuit at the natural POPS frequency might be a way to generate POPS energy without an RF supply.

It should go in series with the DC supply and be just before the grid input connection to the reactor.

This would make any RF generated naturally synchronized with the internal oscillations of the reactor. Phasing could be adjusted some by detuning the tuned ckt.

A good low impedance capacitor from the HV input to the LC circuit to the ground side of the supply would be a very good idea.

This is beginning to look a lot like Tesla Coil country. In fact this Tesla Coil CAD program might be of some use for coil winding and calculating resonant frequencies. Or formulas if you want to check the prepackaged calculators or roll your own. A list of Tesla CAD programs. A self resonance coil calculator.

You can check them against this equation as long as the coil desired is at least as long as its diameter.

Fmhz = (29.85 x (H/D)^1/5)/(N*D)

F= self resonant frequency in Mhz of an 'isolated' coil
H= coil height in meters
D= coil diameter in meters
N= total number of turns

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Update: 03 Feb 008 0714z



If the coils are made close to self resonance then a very small capacitor can be used to resonate the coil. That means the unit could be tuned over a small range by putting a sheet of dielectric between the capacitor plates.

The first thing to do is to get your fusor operating properly and then use a spectrum analyzer or 100KHz to 30 MHz radio receiver to find out what the natural frequency is.

A high frequency capacitive voltage divider with a diode detector hooked to the HV between the LC and the grid would be a good idea for tuning the coil. Tune for maximum RF.

The HV side could be from .5 to 2 pF (depending on frequency). With the low side capacitance on the order of 50 to 200pF (dependent on the high side capacitance). What you want is 100:1 divide ratio. Roughly. To start. If you use a 1N4148 diode as a detector. You should be able to go from about 100 VAC to 3000 VAC (diode limit is 3750 VAC - actually 1/2 of 75 PIV guaranteed*100). If the voltages you get are outside that range adjust your divider accordingly. The exact range is not too important as you are using it for tuning and not measurement. A voltage in the range of 5 to 10 V at peak output should give plenty of margin and yet give good tuning indication.

A lot is going to depend on lead dress. Keep everything as short as possible. The leads and everything that they contact is now part of your tuned circuit. As much as possible on the HV DC go for a single point ground.

What I'm thinking is that we have a Q multiplier here. If we use Q multiplication to raise the RF at the grid that should enhance the production of RF further raising the RF drive.

It will be interesting to see if it has any effect on fusion output. And what it does to losses.

Any way there is something like a 10% or 20 % chance we will do it this way. If it works you could control the feedback by adjusting the tuning.

Another way to tune it to start would be to use a fluorescent tube in the vicinity and tune for maximum brightness. That should be good enough to start.

Let me add one minor word of caution. We may not use this on the initial test devices until we are sure of the stability and frequency of POPS. For testing it would be more useful to have a power amplifier driven system with octave band output filters.

I have put a bit up at fusor.net about this and it seems there is an interested party. If he gets results I might change my attitude.

A while back some folks were fantasizing about how to use a Tesla coil to run a fusion machine. It looks like it might be the other way around.

Update:

Here is another design idea for how to do POPS that will be a little safer. The coil and tuning capacitor both have one end grounded. Again. A star ground for the HV will tend to reduce common mode voltages and currents.

Note that C includes coil self capacitance.


If the output of POPS is low a good rough indicator would be a NE-2 neon lamp [pdf]. Get the ones with leads. You can also raise the sensitivity by applying an AC voltage (mains power) to the lamp.

I built one of these 50 years ago when I was in the process of getting my my first Amateur license, K0NMR. They work pretty good.

Update: 04 Feb 008 0521z

Have a look at the wiki on Klystron Tubes. It uses the natural bunching of electrons to create microwave frequencies. Since we will be using ions which weigh 3600 times as much as an electron (D-D) the frequencies will be 60 times lower.

POPS oscillation is proportional to (Vwell/Mion)^0.5/Rwell according to the POPS paper by Park. For a 30 KV supply voltage POPS should be around 6 MHz in a small Reactor. In any case it has a very high probability of being in the .1 to 30 MHz range.

Note that like a klystron the POPS oscillator frequency changes with operating voltage. Suppose we got an impossibly high Q of 1,000 for the tuned circuit. that would mean we needed to hold the frequency within better than .1% (1 part in 1,000) to get the maximum effect of the tuned circuit. That means holding the voltage steady to better than .2%. Difficult. Not impossible. Of course with lower Qs wider excursions are possible. It means low ripple and low voltage servo variations. Servo variations of under .1 % imply open loop gains in the passband of over 1,000. Some fun.

Say we use 80 stacked 1,000 V @ 10 A supplies. The supplies would have to regulate to better than 1 V at full output and have less than 1 V ripple. At 30 KHz operating frequency that implies an output capacitance of 22 uF @ 1500 V rating. Able to carry 5A 30KHz AC without excessive dissipation.

Since this will effectively be an 80 phase supply due to the sequential firing of the stacked modules there will be some reduction of output ripple due to the stacking. That will come in handy at lower voltages where the allowable ripple becomes less.

The allowable bandwidth of the voltage control servo is in the 1 KHz to 3 KHz range due to the 30KHz operating frequency of the switching supplies.

It may also be possible to mechanically slew the tuned circuit frequency by .2% with a speaker capable of 10 KHz response connected to a small segment of the tuning capacitor. If that was the case, as long as the system was relatively stable in the 100 microsecond time frame the tuned circuit could be kept on frequency. A VSWR detector in the HV line could do that. What you would do is compare the phase of the RF current in the line with the phase of the RF voltage on the tuned circuit and use that to servo the speaker.

Here is how POPS might be done with Amplifiers. We might need to add in an automatic phase adjuster or a PLL to keep things properly tuned up. You can click on the dwg to make it larger.


Back of the envelope calculations say that for a 50 KV DC 50 Amp grid supply (2.5 MW) an RF Amplifier capable of 250 w to 1,000 w should do the trick if using an LC circuit is not practical.

I used the wrong envelope. If the p-p voltage required is 4% of the DC voltage that represents 2,000 V p-p. That would be roughly 1,500 VRMS. Assuming a the real component of the load is 1,000 ohms (same as the DC load) that gives about 25 KW. Doubling the p-p voltage would require about 100 KW.

At those kinds of powers it may be useful to run the RF generators from the HV DC supply.

WB-100 Superconductor Magnet Cooling

I have been working on some of the cooling issues for WB-100 - the 100 MW test reactor using superconducting magnets.

The magnet will consist of a series of concentric pipes. The innermost will contain the superconductor and its coolant at 20K. Next will come a vacuum space and next will come LN coolant. In the vacuum space between the superconductor coolant and the LN coolant the walls will be silvered (or some such) to minimize the radiative heat flow between the superconductor coolant and the LN. Think thermos bottle.

Next space after LN coolant will be another vacuum space. It too will be silvered. Then H2O coolant at around 300K. Another silvered vacuum space. And finally H2O coolant at around 600K.

What we are going to have is a series of concentric vacuum bottles with LHe at 20K at the center and H2O at 600K at the outside. All this plumbed to allow enough flow to keep everything at the proper temperature.

Let me add that any electrons ejected from the surface of this contraption will carry away minimal energy. The alphas will be hitting with 2MeV+. The electrons (those that are not lost due to high energy) will be at 50KeV.

My current plan is to coat the outer surface of the coils with Boron which melts at 2349 K. The purpose is to prevent sputtering of the metallic pipes holding the coolant so the only material sputtered into the reactant space will be a reactant - B11. It has been suggested at Coulter Smithing that an outer sheath for the coil of Titanium might work well since any sputtered atoms would act as a getter. OTOH it might poison the reaction. Lots of unknowns here. We may just have to build one and see what happens.

If we use Boron, we will have to figure out how to balance Boron condensation on the outer magnet structure with Boron sputtering from the reaction.

Below is a picture of a cross section of the superconducting coil.

Update: 06 Feb 008 2046z

I was thinking. Since for a power reactor we will need to water cool the coils. Suppose we made the water jacket thick enough to thermalize neutrons. And then had a B10 layer to absorb them.

It should be possible to cut way down on coil damage and still run superconductors in a D-D machine.

MgB is interesting in that it becomes a better superconductor with some neutron damage

With MgB the resistivity goes up. Critical Field goes up. And critical temperature declines slightly.

The main problem seems to be defects caused by B10 absorbing neutrons.

If B10 was used in shielding and B11 used to make the superconducting wire much longer lifetimes in neutron fluxes should be possible.

The the cross section difference is six orders of magnitude B10 to B11. With B10 @ 10,000 barns at .025 eV and B11 @ .01 barns.

Magnesium has a cross section of about .75 for 2.5 MeV neutrons

Mg is .063 Barns for Thermal Neutrons.

Which says that if we can get an operational life of the superconductors at 10 hours with ordinary Boron, a year should be possible with five to six nines pure B11.

Reduce the Flux another factor of 10 with water moderation and a B10 absorption layer and you are up to 10 years operation. Double that Boron 10 thickness and you are up to 100 years. Which should allow for various inaccuracies and production variations.

10 B has a Maxwellian thermal neutron flux cross section of almost 4,000 barns.

11 B is around .1 barn.

At room temperature Borax B(OH)3 is soluble at about 57 g/ liter. Which is about 9.3 g/ liter of B10.

Maximum properties of MgB occur at 2E18/cm^2 total neutron flux. Let us say 1E18 and have some safety margin.

Typical fission reactor neutron flux is 1E12/second. Let us say because of the lower energy per reaction a D-D reactor would have 50X that flux.

So that is 20,000 seconds at full power with natural boron. Say 4 1/2 hours. If we go to B11 superconductors assume a 1,000 time improvement. That is 4,500 hours. Say 6 months roughly. So we need a B10 shield that can reduce the neutron flux at the coils by a factor of 10. Giving a life of 5 to 7 years continuous operation.

Since MgB is cheap, replacing the coils every 5 to 10 years should not be a big burden. In addition preconditioned coils capable of sustaining 30 T might get a premium.

Update: 07 Feb 008 0414z

revised thicknesses
I think it is worthwhile to look at the B10 thickness required to absorb 1/10th of the incident thermal neutrons. I calculated it and came up with .005 cm. That is right 5 thousandths of a cm. To slow the neutrons from an average of 2 MeV to .025 eV (thermal energy) requires a thickness of water of about 2 1/4 inches (5.7 cm). About what I would expect to need on the basis of heat transfer and pumping considerations alone. It might be possible to include that B10 thickness (or even 3X that) in the construction of the 300K coolant channel. Just deposit it on the interior since there is no heat transfer consideration (except pumping losses from wall roughness) involved.

At a flux of 1E12 neutrons a second per sq cm., 1 sq cm will have a total flux of 3.16E20 in 10 years. To handle that number of disintegrations would require a thickness of .003 cm. Not too tough. Since the actual density required could be cut in half without seriously affecting the required volume of absorber, it might work out to fill an extra layer with boron powder. That way any break up of "structure" from radiation damage would have little effect on the absorbing properties compared to initial conditions. A layer .1 cm thick could be adequate if you recompressed it from time to time. Certainly a cm or two would be overkill.

I forgot that a D-D reactor with the same thermal power out as a fission nuke will produce about 50X as many neutrons. The 1E12 factor is based on a fission nuke. Still not a show stopper.

Update:

I have a show stopper. Each neutron absorbed produces 2.8 MeV. In a D-D reactor there is no way to carry the heat away without adding more water layers. At best a very thin layer might buy us some operational time for a test reactor. The advantage may go to using a B11 superconductor even with its lower Tc. That still only gets us months of operation. Probably good enough for experimental work.

BTW the neutron flux in a D-D reactor with a coil radius of 2 m at the coil radius is on the order of 3E14 neutrons a second at 100 MW fusion output.

Further Update:

With an intermediate layer filled with borated water to absorb 99% of the neutron energy, or 99.9%, you might get the flux down to where powdered boron could handle the rest. Great idea. At 9.3 g/l that is 9.3E-4 g/cc. Compared to 2 g/cc that would require about 10 cm - vs .005 cm for a factor of 10 reduction. Not going to work. So it still looks like MgB11 superconductors with B11 at 4 nines or better. That still only buys you a total of 1,000 hours - probably enough for initial experimental work at 100 MW.

If you could maintain a slurry of boron particles and still keep the whole contraption cool - it might work.

The trouble is that it almost doubles the neutron thermal load (1.75X). The neutrons lose 3.65 MeV thermalizing and then the B10 adds a 2.8MeV alpha. Which increases the total heat load by about 40% in what was already a marginal situation.