The Current State Of Fusion

Alan Boyle at Cosmic Log has the latest broad look at the state of Fusion. He discusses the state of laser fusion. The the $3.5 billion American National Ignition Facility seems to be doing well. But what excites me is that he has some indirect news on The Polywell Fusion Reactor experiments.

The dark horse in the fusion race is an approach known as inertial electrostatic confinement fusion, or Polywell fusion. This method, pioneered by the late physicist Robert Bussard, involves designing a high-voltage cage in such a way that atomic nuclei slam into each other at high speeds, sparking fusion.

That is the hope. Now what about some news?

In September, EMC2 Fusion was awarded a Navy contract, backed by $7.9 million in stimulus funds, to develop a scaled-up version of a Polywell fusion reactor. Development and testing of the device is expected to take two years, and there's an option to spend another $4.4 million on experiments with hydrogen-boron fuel (known as pB11).

In the past, EMC2 Fusion's Richard Nebel has been able to describe the team's progress in general terms, saying that he was "very pleased" with the performance of an earlier test device. But now, with more Navy money on the line, Nebel has been constrained from saying anything about the project. The fact that the research is continuing, however, appears to indicate that the results have been promising enough to keep the Navy interested.

My sources on the project have dried up as well. No one is talking. I am running on unsupported rumors and conjecture. Some think that the silence is a cover up for failure. Being a fanboy I'm more inclined that they are so wildly successful that the Navy doesn't want to let the cat out of the bag any sooner than they can help. Reality is probably some where in the middle or worse. The design is so simple that if the Navy gets it to work no country is more than 5 years behind in producing a working model from scratch (given a crash program).

As you know I have been closely following the progress of the WB-X contracts at EMC2. If you want to get deeper into them:

WB-8 Contract Progress

Polywell Gets The Dough

The Boys At Talk-Polywell Have Struck Paydirt

WB-8 In The Works

Polywell Gets In On The Act

You can learn the basics of fusion energy by reading Principles of Fusion Energy: An Introduction to Fusion Energy for Students of Science and Engineering

Polywell is a little more complicated. You can learn more about Polywell and its potential at: Bussard's IEC Fusion Technology (Polywell Fusion) Explained

The American Thinker has a good article up with the basics.

And the best part? We Will Know In Two Years

H/T rschaffer8 at Talk Polywell

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

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.

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.

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