Dry-run experiments verify key aspect of Sandia nuclear fusion concept

Sep 17, 2012
Sandia researcher Ryan McBride pays close attention to the tiny central beryllium liner to be imploded by the powerful magnetic field generated by Sandia’s Z machine. The larger cylinders forming a circle on the exterior of the base plate measure Z’s load current by picking up the generated magnetic field. Credit: Randy Montoya

(Phys.org)—Magnetically imploded tubes called liners, intended to help produce controlled nuclear fusion at scientific "break-even" energies or better within the next few years, have functioned successfully in preliminary tests, according to a Sandia research paper accepted for publication by Physical Review Letters (PRL).

To exceed scientific break-even is the most hotly sought-after goal of fusion research, in which the energy released by a is greater than the energy put into it—an achievement that would have extraordinary energy and defense implications.

That the liners survived their electromagnetic drubbing is a key step in stimulating further Sandia testing of a concept called MagLIF (Magnetized Liner ), which will use magnetic fields and laser pre-heating in the quest for energetic fusion.

In the dry-run experiments just completed, cylindrical beryllium liners remained reasonably intact as they were imploded by huge of Sandia's Z machine, the world's most powerful pulsed-power accelerator. Had they overly distorted, they would have proved themselves incapable of shoveling together —deuterium and possibly tritium—to the point of fusing them. Sandia researchers expect to add deuterium fuel in experiments scheduled for 2013.

"The experimental results — the degree to which the imploding liner maintained its cylindrical integrity throughout its implosion—were consistent with results from earlier Sandia computer simulations," said lead researcher Ryan McBride."These predicted MagLIF will exceed scientific break-even."

A simulation published in a 2010 Physics of Plasmas article by Sandia researcher Steve Slutz showed that a tube enclosing preheated deuterium and tritium, crushed by the large magnetic fields of the 25-million-ampere Z machine, would yield slightly more energy than is inserted into it.

A later simulation, published last January in PRL by Slutz and Sandia researcher Roger Vesey, showed that a more powerful accelerator generating 60 million amperes or more could reach "high-gain" fusion conditions, where the fusion energy released greatly exceeds (by more than 1,000 times) the energy supplied to the fuel. See http://phys.org/news/2012-03--simulation-high-gain-energy.html .

These goals—both the near-term goal of scientific break-even on today's Z machine and the long-term goal of high-gain fusion on a future, more powerful machine—require the metallic liners to maintain sufficient cylindrical integrity while they implode.

The liner is intended to contain fusion fuel like a can holds peanut butter, and push it together in nanoseconds like two semicylindrical shovels compacting snow together.

An element of drama is present because the metallic liner doing the compressing is also being eaten away as it conducts the Z machine's enormous electrical current along its outer surface. This electrical current generates the corresponding magnetic field that crushes the liner, but under the stress of passing that current, the outer surface of the liner begins to vaporize and turn into plasma, in much the same way as a car fuse vaporizes when a short circuit sends too much current through it. As this happens, the surface begins to lose integrity and becomes unstable. This instability works its way inward, toward the liner's inner surface, throughout the course of the implosion.

"You might say: The race is on," said McBride. "The question is, can we start off with a thick enough tube such that we can complete the implosion and burn the fusion fuel before the instability eats its way completely through the liner wall?

"A thicker tube would be more robust in standing up to this instability, but the implosion would be less efficient because Z would have to accelerate more liner mass. On the flip side, a thinner tube could be accelerated to a much higher implosion velocity, but then the instability would rip the liner to shreds and render it useless," he continues. "Our experiments were designed to test a sweet spot predicted by the simulations where a sufficiently robust liner could implode with a sufficiently high velocity."

By following the dimensions proposed by the earlier simulations, the physical test proved successful and the liner walls maintained their integrity throughout the implosion.

Radiographs taken at nanosecond intervals depicted the implosion of the initially solid liner through to stagnation—the point at which an implosion stops because the liner material has reached the cylinder's central axis. The images show the outer surface of the imploding liner distorting until it resembles threads on a bolt. However, the more crucial inner surface remains reasonably intact all the way through to stagnation.

Said McBride's manager Dan Sinars, "When Magnetized Liner Inertial Fusion was first proposed, our biggest concern was whether the instabilities would disrupt the target before fusion reactions could occur. We had complex that suggested things would be OK, but we were not confident in those predictions. Then McBride did his experiments, using liners with the same dimensions as our simulations, and the outcomes matched. We are now confident enough to take the next steps on the Z facility of integrating in the new magnetic field and laser preheat capabilities that will be required to test the full concept. Consequently, we intend to take those first integration steps in 2013."

Slated for December are the first tests of the final two components of the MagLIF concept: laser preheating to put more energy into the fuel before magnetic compression begins, and the testing of two secondary electrical coils placed at the top and bottom of the can. Their magnetic fields are expected to keep charged particles from escaping the hot fuel horizontally. This is crucial because if too many particles escape, the fuel could cool to the point where fusion reactions cease.

Sandia researchers intend to test the fully integrated MagLIF concept by the close of 2013.

"This work is one more step on a long path to possible energy applications," said Sandia senior manager Mark Herrmann.

The liner implosion experiments also served to verify that simulation tools like the popular LASNEX code are accurate within certain parameters, but may diverge when used beyond those limits—information of importance to other labs that use the same codes.

McBride will give an invited talk on his work this fall at the American Physical Society's annual Division of Plasma Physics meeting in Providence, RI. He is also preparing an invited paper for Physics of Plasmas to explain the PRL results in greater depth.

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Shootist
2.6 / 5 (5) Sep 17, 2012
Bussard's Polywell, for the win.
wealthychef
not rated yet Sep 17, 2012
Wow! Breakeven in 2013? Go Sandia! Now after break-even, what is next? Given the size constraints, how does one scale up the process?
jalmy
1.6 / 5 (7) Sep 17, 2012
Well, at that point does it even matter? The one-shot process involved here is worthless for energy generation. The only thing this thing is good for is as a tool for making measurements to aid in better computer simulations of plasma and fusion.
GSwift7
3.7 / 5 (3) Sep 17, 2012
Now after break-even, what is next? Given the size constraints, how does one scale up the process?


The next step will depend on how this goes. They need to know if it's worth building the 60 million amp z-machine or not. If it looks possible, then they seek funding to do it.

Well, at that point does it even matter? The one-shot process involved here is worthless for energy generation


Not really. You capture the heat in some material surrounding the core, such as liquid salts. Then you pump that through a heat exchange to drive high-efficiency multi-phase turbines, just like they do in a common nuclear power plant.

That doesn't matter unless they get it to work though.
GSwift7
3.7 / 5 (3) Sep 17, 2012
Note: The National Ignition Facility is attempting a similar approach with lasers only, and they are a lot farther along in their work than the one above. They don't plan to try fusion for a while yet, but their machine is big enough that they have a chance to reach high gain fusion. A European team managed to get theirs working for half a second, but they were using a different method, which may be too hard to maintain.
ValeriaT
1 / 5 (6) Sep 17, 2012
The cost of single experiment at Sandia is probably higher, than the whole year of cold fusion research. I just impressed with the obstinacy, in which mainstream science ignores the apparent progress in cold fusion. Scientists are like the politicians: both they're payed from mandatory fees and nobody wants to lose his job prematurely here - no matter, how useless it really is.
Moebius
1 / 5 (2) Sep 17, 2012
So they are designing a reactor that has to be fed a steady supply of tin cans? lol
wealthychef
not rated yet Sep 17, 2012
The cost of single experiment at Sandia is probably higher, than the whole year of cold fusion research. I just impressed with the obstinacy, in which mainstream science ignores the http://www.e-catw...t-niweek in cold fusion. Scientists are like the politicians: both they're payed from mandatory fees and nobody wants to lose his job prematurely here - no matter, how useless it really is.

Mainstream science obstinately insists in reproducible and reliable results. If the story reported in your link is correct, it sounds like it will be simple to reproduce and create cold fusion devices within a few months that you can sell to people. I won't hold my breath, because I'm skeptical, but if it works, "mainstream science" will welcome it.
Grallen
5 / 5 (2) Sep 17, 2012
High energy fusion will be capable of greater returns than predicted by cold fusion. Also, Cold Fusion has no provable research yet. If you mean LENR(Low Energy Nuclear Reaction) then say LENR.

The important differences:
High Energy Fusion fuel will cost less/is more abundant.
A High Energy Fusion facility would produce more energy than a cold fusion or LENR facility of Equivalent size.
For High-Energy Fusion. Per energy produced. Equipment will be less expensive (lower cost materials).

There is great investment here because of the potential for unparalleled returns.

If LENR or Cold Fusion research suddenly show promise and was developed through to commercialization. It will likely only be used as an energy alternative stepping stone until High Energy Fusion is realised...

So to make my point very clear to cold fusion enthusiasts: As we approach viable High Energy Fusion, Cold Fusion (whether real or not), becomes less and less relevant...
Grallen
5 / 5 (1) Sep 17, 2012
If the above was too complex. I'm making it clear that Cold Fusion Enthusiast seem not to realise that they are essentially saying: "Why make cars? It's it easier to design bicycles?" Except replace bicycle with something conceptually simple, but as of yet unprovable.
MrVibrating
1 / 5 (2) Sep 17, 2012
Thing is, the energy density of hot fusion has to allow for the more complex apparatus, esp. if radioactives are involved. In LENR all the radiation is thermalised, with no hazardous sources or products. This makes an LENR plant a fraction the size of an equivalent hot plant, not to mention safer, and thus that much more practical, not least with regards to domestic and transportation markets..
Grallen
3.5 / 5 (2) Sep 17, 2012
Fusion is just as safe. As long as people are not stupid enough to touch the steam pipes.
Grallen
1 / 5 (1) Sep 17, 2012
Also >>>per foot<<< of space used and >>>Per dollar invested<<< High Energy Fusion will Produce energy of at least a magnitude more(10x or more).
Egleton
1 / 5 (2) Sep 18, 2012
Grallen, your enthusiasm is encouraging. One technology does not preclude the other. We can walk and chew gum.
How do you think hot fusion would go in auto mobiles? Would a single unit be cheap enough and transportable enough to power Joe Sixpac's urban battle wagon?
The problem we have is the petro-dollar. If that goes then the USA's paper will drop like a stone. Which will be a good thing because it's strength is a handicap to the economy.
BSFusion
1 / 5 (2) Sep 18, 2012
DOES ANYONE KNOW IF THERE IS A NUCLEAR FUSION POWER PLANT HAVING A LIQUID REACTOR CORE OF MOLTEN GLASS THAT IS MADE LASERACTIVE AND FUNCTIONS AS A TRITIUM BREEDING BLANKET WHICH IS CAPABLE OF ACOUSTICLY COMPRESSING/CONFINING FUEL SO THAT IT RADIATES AND TRIGGERS OUTGOING LASER CASCADES THAT WILL REFLECT FROM THE BLAST CHAMBER'S SPHERICAL INSIDE WALL AND RETURN LIKE PHOTONIC TSUNAMIS, CRUSHING, HEATING, AND CAUSING THERMONUCLEAR IGNITION OF THE FUEL SO THAT HEAT ENGINES AND PIEZOELECTRIC HARVESTERS CAN CONVERT THE RELEASED ENERGY INTO ELECTRICITY?
GenesisNemesis
4.7 / 5 (3) Sep 18, 2012
DOES ANYONE KNOW IF THERE IS A NUCLEAR FUSION POWER PLANT HAVING A LIQUID REACTOR CORE OF MOLTEN GLASS THAT IS MADE LASERACTIVE AND FUNCTIONS AS A TRITIUM BREEDING BLANKET WHICH IS CAPABLE OF ACOUSTICLY COMPRESSING/CONFINING FUEL SO THAT IT RADIATES AND TRIGGERS OUTGOING LASER CASCADES THAT WILL REFLECT FROM THE BLAST CHAMBER'S SPHERICAL INSIDE WALL AND RETURN LIKE PHOTONIC TSUNAMIS, CRUSHING, HEATING, AND CAUSING THERMONUCLEAR IGNITION OF THE FUEL SO THAT HEAT ENGINES AND PIEZOELECTRIC HARVESTERS CAN CONVERT THE RELEASED ENERGY INTO ELECTRICITY?


No.
BSFusion
1 / 5 (2) Sep 18, 2012
I'm looking for a nuclear fusion power plant having a spherical blast-chamber filled with a liquid coolant that breeds tritium, absorbs neutrons, and functions as both an acoustical and laser medium. Fuel bubbles up through the sphere's base and is positioned using computer guided piezoelectric transducers that are located outside the blast-chamber. These generate phase-shifted standing-waves that tractor the bubble to the center. Once there, powerful acoustic compression waves are launched. Shortly before these reach the fuel, an intense burst of light is pumped into the sphere, making the liquid laser-active. When the shockwaves arrive, the fuel temperature skyrockets and it radiates brightly. This, photon-burst, seeds outgoing laser cascades that return, greatly amplified, from the sphere's polished innards. Trapped within a reflecting sphere, squeezed on all sides by high-density matter, the fuel cannot cool or disassemble before thorough combustion. Does anyone know where to look?
Torbjorn_Larsson_OM
5 / 5 (1) Sep 18, 2012
@ ValenciaT:

"I just impressed with the obstinacy, in which mainstream science ignores the apparent progress in cold fusion."

Don't be daft, it is precisely because there is no progress - and little expected - that it is ignored. Been there, done that. If it was easy, it would have made progress long since.

@ Grallen:

Exactly. "Why make cars? It's it easier to design witch brooms?"

@ natello:

Conspiracy theories are daft, because they are the least likely pathway by construction as conspirationists doesn't want their bullshit tested. Untestable means unlikely.

Meanwhile, in the real world, the Market Of Ideas in science means everything that works will eventually rise to the surface and be harvested by scientists interested in their own success (and so more $$$). The MOI is a well tested theory of science on science, because few useful ideas has been found to languish in obscurity.
GSwift7
3 / 5 (2) Sep 18, 2012
I'm looking for a nuclear fusion power plant having a spherical blast-chamber filled with a liquid coolant that breeds tritium, absorbs neutrons, and functions as both an acoustical and laser medium. Fuel bubbles up through the sphere's base and is positioned using computer guided piezoelectric transducers that are located outside the blast-chamber... blah blah


Have you checked Craig's List and EBay? You can avoid sales tax that way. :|

As for cold fusion; if only I wasn't so busy working on my transmogrifier... (Calvin and Hobbs reference)
Torbjorn_Larsson_OM
5 / 5 (1) Sep 18, 2012
Ha! I checked on LENR, and it is cold fusion by a new name. It is like when creationists renamed "christian science" to "intelligent design", and took it out for a new spin around the world.

In other words, it is *worse* than cold fusion, because decades of no progress has forced them to rename their scam. Last high time scammer, Rossi, has finally been forced to show a failed demonstrator. Apparently the old "make a faulty electric power measurement, that will fool enough investors" still works.

Wonder what scam LENR will parade around next...
rubberman
1 / 5 (1) Sep 18, 2012
Nat- I have to assume you subscribed to the LENR news letter that was supposed to be a monthly release and stopped several months ago, do you know why they stopped sending it?

GSwift- In the Z machine the magnetic field also helps to control energy the fusion reaction generates, do you know how they would control the reaction if they are initiating it with lasers?
GSwift7
3 / 5 (2) Sep 18, 2012
GSwift- In the Z machine the magnetic field also helps to control energy the fusion reaction generates, do you know how they would control the reaction if they are initiating it with lasers?


As I understand it, the Nat Ignition Fac device is just a bunch of lasers focused at the same point from all sides. They intend to place a spherical fuel pellet in the middle and use the shockwave of the outer shell of the fuel pellet vaporizing to create enough internal velocity in the fuel to achieve fusion. It would be a pulsed reaction rather than a continuous one. You don't really want to contain anything in this setup. You just need heat sinks surrounding it, to collect the heat of the reaction and eventually boil some liquid for turbine generators. If they can get it to work, then they'll worry about repeating it fast enough to be useful and designing a method to change the energy into a useful form. That's really the easy part though.
bger
not rated yet Sep 18, 2012
Beryllium is pretty nasty stuff, biologically speaking -- so in any practical application, there'd have to be a 100% guarantee that it couldn't escape containment. I know that's merely a mundane engineering problem, but a similar flaw doomed the Sodium (fission) Reactor Experiment, years ago.

Personally, I like the fusion reactor we ALREADY have, conveniently located 93 million miles away! Even at that distance, it presents a radiation hazard to us humans ;-)...
Vendicar Dickarian
1 / 5 (2) Sep 22, 2012
If the above was too complex. I'm making it clear that Cold Fusion Enthusiast seem not to realise that they are essentially saying: "Why make cars? It's it easier to design bicycles?" Except replace bicycle with something conceptually simple, but as of yet unprovable.


True, though you're missing one important element: the cold fusion "philosophers" also claim that cold fusion is extremely cheap, and thus available to all for the cost of an ice cream sandwich. Whereas hot fusion is ridiculously expensive.
TylerH
not rated yet Sep 22, 2012
Personally, I like the fusion reactor we ALREADY have, conveniently located 93 million miles away! Even at that distance, it presents a radiation hazard to us humans ;-)...


The problem there being that we don't actually have it in the context of this conversation. At least not until we can harness energy at near-perfect efficiency with solar energy solutions. I wouldn't complain were that to happen, though.
Vendicar Dickarian
1 / 5 (2) Sep 22, 2012
DOES ANYONE KNOW IF THERE IS A NUCLEAR FUSION POWER PLANT HAVING A LIQUID REACTOR CORE OF MOLTEN GLASS THAT IS MADE LASERACTIVE AND FUNCTIONS AS A TRITIUM BREEDING BLANKET WHICH IS CAPABLE OF ACOUSTICLY COMPRESSING/CONFINING FUEL SO THAT IT RADIATES AND TRIGGERS OUTGOING LASER CASCADES THAT WILL REFLECT FROM THE BLAST CHAMBER'S SPHERICAL INSIDE WALL AND RETURN LIKE PHOTONIC TSUNAMIS, CRUSHING, HEATING, AND CAUSING THERMONUCLEAR IGNITION OF THE FUEL SO THAT HEAT ENGINES AND PIEZOELECTRIC HARVESTERS CAN CONVERT THE RELEASED ENERGY INTO ELECTRICITY?


Yes, it is sold by Andrea Rossi. And, he also promises that it will cut your grass, wax your car, and do your dishes.
ValeriaT
1 / 5 (2) Sep 23, 2012
Andrea Rossi is actually quite insignificant in proof of real existence of cold fusion. He never wrote any reproducible report about it. It's hundred of serious scientists like the Hagelstein from MIT, Cellani, Piantelli and Focardi from Italy, Zawodny from NASA etc. All these people are claiming the excess of energy, which gives the sense to the cold fusion research. You cannot ignore the existence of all these people. Actually when someone tries to deny the existence of old fusion just with doubting of Andrea Rossi (who is the most visible, but the weakest member in the chain of evidence), then it's clear for me, he is pathological skeptic, who doesn't care about any real evidence and whose only motivation is to simply deny the existence of cold fusion as such. It's a demagogy of cold fusion opponents.
ValeriaT
1 / 5 (2) Sep 23, 2012
The whole problem is actually as simple, as follows: If we can be perfectly sure, that the cold fusion effect is real at least a bit and if we know, that the fusion may lead to release of immense energy corresponding the thermonuclear fusion, then the cold fusion research should have absolute priority before all alternative ways of energy productions, because we know, these methods all have their apparent limit - which is way lower, than the thermonuclear fusion.

I know about it, you know about it - and the opponents of cold fusion - who are usually engaged in alternative ways of energy production, conversion, transport or storage indeed know about it as well. Which is the reason, why they're so hostile against every success of cold fusion. And of course, the Andrea Rossi is easiest target in this moment. They cannot doubt the serious researchers, because their experiments can be repeated any time - which is something, which they cannot admit. So they're doubting the Andrea Rossi.
ValeriaT
1 / 5 (2) Sep 30, 2012