Print 25 comment(s) - last by CBRworm.. on Feb 20 at 12:40 PM

  (Source: Fusenet)
The output power has been bumped 10x, gains come thanks to improved alpha particle, neutron yields

It will likely be decades before mankind taps into the sun's power source, using fusion to provide cheap, clean power for mankind's ever evolving ambitious.  While some physicists remain convinced that mankind may not ever be able to harvest reliable power from direct nuclear fusion reactions, U.S. national lab researchers took a step down that path, publish a paper in Nature which detailed "fuel gains" -- small bursts in which power produced eclipsed the power consumed to trigger and drive the reaction.
I. Now We're Cooking
The research was conducted at Lawrence Livermore National Laboratory's (LLNL) National Ignition Facility (NIF) -- a site that politicians were complaining just two years ago was the "mother of all boondoggles".  But LLNL has since then silenced most of these detractors by doing what all researchers aim to do -- produce results.
Late last year it announced that its laser-confined fusion chamber had achieved "self-sustaining burning" for a brief period.  During the test the reactor was roughly energy neutral at a pellet level, albeit at a massive energy deficit when all the support equipment (lasers, etc.) were considered.

NIF Hohlraum
Fusion occurs inside a tiny chamber heated by X-Rays. [Image Source: LLNL]

Refining its technique from a "porcupine" or "low-foot" style laser pulsing technique to a so-called "high-foot" implosion, researchers were able to achieve greater stability over the last several months.

Last year's shots pumped 1.7 MJ (1.8e6 J) of laser energy into the hohlraum -- German for "hollow room" -- a small metal vessel that absorbs and transfers heat to the fusion fuel pellet.

NIF Pellet
A cryogenically chilled hydrogen DT isotope fuel pellet [Image Source: LLNL]

In the latest tests, with the new implosion method researchers were able to pump up the energy to 1.9 MJ, of which about half actually heats the fuel, roasting the 2 mm pellet of deuterium and tritium (fusible hydrogen isotopes, respectively) with an insanely hot X-ray bath.  The amount of energy the tiny pellet endures is comparable to the amount of energy of a one-ton car travelling at 100 miles-per-hour (160 km/h).

NIF pellet
A view shows how the lasers heat the outer gold vessel, frying the pellet towards fusion. [Image Source: LLNL/Nature]

That laser power compresses the hot spot of the pellet under 126-152 Gigabar (trillion bar).  The entire construct is heated to 13-15 MeV (million electron-volts) -- around 3.3 million Kelvin.

That fire is preceded by ice.  The tiny pea-sized pellet was chilled for the "shots" down to 18.3 K (-254.8 ºC).

NIF fuel pellet
The fuel pellet is coated in icy isotopes. [Image Source: APS]

The pulse takes about 20 ns, during which roughly 450 Terawatts of power is transferred to the pellet, or roughly 450 times the power transferred during a lightning strike.  The result is a hot spot, followed by an implosion followed, by the generation of fast alpha particles and neutrons.
II. Might as Well be Walking on the Sun
In test shots using the new high-foot method, researchers were able to achieve a roughly 1.2-1.4 times gain in the energy produced by the fusion event over the energy that applied to the pellet.  A second shot, at slightly higher power saw 1.8-2.0 times gain.
That's 10 times better than the best results to date for deuterium and tritium.

NIF yield
The NIF has been steadily bumping its energy gains. [Image Source: Nature/LLNL]

But don’t get too excited; the experiment did not achieve the ultimate goal of fusion research -- ignition (not that it was supposed to).  Ignition is the point at which a reaction produces more power than it consumes over its lifecycle.  It takes a lot of power to get there. 
The capacitors that pump the lasers draw a whopping 422 Megajoules of energy while active.  Less than one percent -- roughly 3 Megajoules -- reaches the infrared stage that directly drives the lasers.  And then roughly another third is lost in transit.

NIF laser positioning
Modern lasers are as much as 15 times more efficient than the capacitor pumped ones used by the NIF. [Image Source: LLNL]

At best the researchers observed around 3.8 MJ -- recovering just under a hundredth of the energy they put into the device, not counting measuring equipment and other indirect power expenses.
III. Fast Helium Nuclei Excite, Hint at Future Ignition
But as the old saying goes, you have to spend money to make money.
While researchers expected the inertial confinement fusion (ICF) to be imperfect, they struggled for much of the last several years with why they were getting results inferior to what their simulations had predicted.  The answer seemed to lie in a flawed firing technique, which gave rise to so-called hydrodynamic instabilities during the implosion, preventing the pellet from reaching its maximum compression.
Using the new high-footed firing method researchers appear to have mostly overcome that roadblock.  Their neutron and fast alpha particle radiation has risen substantially, at last approaching the results predicted by theory.  For the first time these particles had sufficient energy to see so-called "bootstrap" effects, enhancing the energy output of the reaction.
Fusion reaction
Bootstrapping is critical to achieving "runaway" long-burn fusion and ignition.

Researchers consider that a crucial step on the road to fusion.  In the researchers journal article abstract they stated optimistically:

We also see a significant contribution to the yield from α-particle self-heating and evidence for the ‘bootstrapping’ required to accelerate the deuterium–tritium fusion burn to eventually ‘run away’ and ignite.

The results are forcing physicists to take ICF -- long regarded as the inferior counterpart of magnetic confinement fusion (MCF) -- seriously.  Even as work continues on the world's biggest MCF fusion project to date, International Thermonuclear Experimental Reactor (ITER), the NIF is showing it has what it takes to steal the spotlight.

Solar storm
Fusion indirectly provides most of the Earth's chemical stored energy, via the Sun.
[Image Source: NASA]

That's in many regards a vindication of LLNL researcher John Nuckolls, who was first allowed to publicly reveal the compression and heating effects in 1972.  Mr. Nuckolls' theories had been in the crosshairs following earlier tests' inability to produce significant amounts of high-energy atomic particles.  Now some skeptics are becoming more receptive to the idea of ICF as a potential alternative to complement the MCF path.
Researchers expect to next cross another critical milestone by pushing the apparatus a bit harder.  Currently the bootstrap heating is narrowly eclipsed by the heating energy from the shot.  If it can surpass that total, the NIF will take another bold step towards making the dream of nuclear fusion power a reality.

Sources: Nature, LLNL, Physics Journal

Comments     Threshold

This article is over a month old, voting and posting comments is disabled

The Sun's power.
By drycrust3 on 2/15/2014 2:52:00 PM , Rating: 2
It will likely be decades before mankind taps into the sun's power source

I do wonder whether the sun's heat is a consequence of it's huge gravitational strength, not the consequence of nuclear reactions deep inside the sun.
For example, we know that Jupiter produces more heat than it receives from the sun, and it has the most mass of any planet in our solar system.

RE: The Sun's power.
By BRB29 on 2/15/2014 3:21:50 PM , Rating: 4
the sun is made of plasma. Plasma is caused by its huge gravitational force and extreme heat on hydrogen gas. Nuclear fusion is also caused by its huge mass and gravity.

Heat is made from the friction of atoms. Almost all the heat is made from nuclear fusion that takes a very long time to get to the surface. It is calculated that it takes 1500 years for a photon to get from the nucleus, where nuclear fusion occurs, to the surface. Another 8.5 mins to get to earth.

Jupiter is nothing more than a really small sun as it is a gas giant. Some even call it a failed dwarf star as it is too small to become a real star. Jupiter does have its own heat but it also get energy from the sun. Think of it as a planet sized failed star.

RE: The Sun's power.
By wordsworm on 2/15/14, Rating: 0
RE: The Sun's power.
By Reclaimer77 on 2/16/14, Rating: -1
RE: The Sun's power.
By wordsworm on 2/16/2014 11:23:52 AM , Rating: 3
Jupiter is mostly made up of hydrogen--the same as what we have from the sun. That might be why he said what he did. The formation of Jupiter and the sun would be roughly the same: dust clouds pulling together to form an entity such as a star or planet. The precise nature of Jupiter's formation is a matter for speculation at best since we'll never be able to travel back in time or even take a close look.

RE: The Sun's power.
By lexluthermiester on 2/18/2014 7:48:25 PM , Rating: 2
It is calculated that it takes 1500 years for a photon to get from the nucleus, where nuclear fusion occurs, to the surface.

Not even close. It takes aprox 50,000 years for a photon of light[or any other type of energy] to reach the surface from the core of the Sun.

Another 8.5 mins to get to earth.

It is actually more like 8.3 minutes.

Jupiter is nothing more than a really small sun as it is a gas giant.

VERY incorrect. Jupiter would need aprox 22 times more mass to even have a slight chance of becoming the smallest of red dwarf stars. Jupiter is not even close to being a "failed" star. It is, in fact, just a gaseous planet.

You need to do some fact checking before making such statements.

RE: The Sun's power.
By lexluthermiester on 2/18/2014 7:59:25 PM , Rating: 2
And before anyone argues;

Time of light from creation to emission as calculated by NASA is nearly 1 million years but other sources gives the average of 50,000;

Distance of Earth from Sun/Speed of light per second/60 seconds per minute;

Mass of Jupiter and various pieces of information.

RE: The Sun's power.
By delphinus100 on 2/16/2014 7:37:00 PM , Rating: 2
It was calculated long ago how much/how long the Sun could radiate energy from simple gravitational contraction...and it just wouldn't be long enough to be consistent with what we know of the age of the Earth:

RE: The Sun's power.
By nafhan on 2/17/2014 11:12:24 AM , Rating: 2
There's not really much doubt regarding whether or not nuclear fusion is actually occurring in the Sun (or at least that it was occurring about 8 minutes ago :)).

The wiki synopsis of this is a nice read:

And, being Wikipedia, there's references listed and links if you want to look into it further.

um no
By Umgar on 2/14/2014 6:41:19 PM , Rating: 5
roasting the 2 mm pellet of deuterium and tritium (fusible hydrogen and helium isotopes, respectively)

deuterium and tritium are both hydrogen isotopes with one and two neutrons, respectively.

RE: um no
By HoosierEngineer5 on 2/14/2014 7:06:44 PM , Rating: 2
"The amount of power the tiny pellet endures is comparable to the amount of energy of a one-ton car travelling at 100 miles-per-hour (160 km/h)."

Power <> Energy. Energy = Power x Time

RE: um no
By HoosierEngineer5 on 2/14/2014 7:16:20 PM , Rating: 2
"At best the researchers observed around 3.8 MJ -- recovering just under a hundredth of the power they put into the device, not counting measuring equipment and other indirect power expenses."

And, again. Should be, "of the energy they put". A tiny amount of power over a very long time is a lot of energy. A lot of power over a very short time is a little energy.

A 1000 watt light bulb turned on for 1 second requires very little energy. A 10 watt light bulb burning for 1000 years uses a lot more energy. Just look at your electric bill if you don't believe me.

RE: um no
By HoosierEngineer5 on 2/15/14, Rating: 0
RE: um no
By Mint on 2/15/2014 7:54:32 AM , Rating: 2
Looks like he fixed that now, but here's another blip:

126-152 Gigabar (trillion bar)

Giga is billion and tera is trillion.

Fission and Fusion are different
By Floorbit on 2/15/2014 3:36:02 PM , Rating: 4
How is this contained if and when there is success ?

The sun continues. However without oxigen . In the midst of space,alone within its own contribution to mass,and space.

The space would not ignite a surrounding exposurer ?

Also the idea of having the atoms super cooled at the start is good. I've often thought about friction contents where solid and gas have none. But at the nano level,if scaling was possible. Where that scale is actually for the microcosm.

RE: Fission and Fusion are different
By Floorbit on 2/15/2014 3:38:30 PM , Rating: 2
edit:where you wanted controlable leverage on that scale. (supercooling,and properties,theories,yeilds etc.)

RE: Fission and Fusion are different
By Floorbit on 2/15/2014 3:42:12 PM , Rating: 2
example:instead of lasers (or with same construct). Shoot a supercool atom,at a superhot one. Or superhot atom,at a supercool one. Looking for that kind of result.

By Floorbit on 2/15/2014 3:53:22 PM , Rating: 2
May need a certain amount of space'for the suns energies to occur. Since its compression creates gravity,via mass (I'm thinking of Maxwells rules of thermodynamics).

The ideas of just how 'cold'space is may not be as a self serving model.

Wonder if Voyager has some tempurature readings out on the edge of suns effects.

By superPC on 2/14/2014 10:36:06 PM , Rating: 2
Laser is only one way of fusing atoms. Meanwhile DailyTech never bother writing about this :


By Mint on 2/15/2014 7:48:36 AM , Rating: 2
There's a lot of new fusion and fission concepts out there. Another example is fusion by dense plasma focus, which in theory is far better than what you linked to due to using aneutronic fusion and not even needing thermal to electric conversion.

DT can only write about so many in one piece, and the links you gave show that Lockheed-Martin is very secretive about this. That's understandable given the implications of this technology, but it would make for a rather useless tech article. He talks about a high beta, stronger field away from the center, and low leakage, but gives no details about the geometry used to achieve such a feat.

On top of that, there's no peer reviewed research on their techniques. I'm a skeptic until I see more information.

By Jeffk464 on 2/15/2014 1:42:34 PM , Rating: 3
If you ask me this is to important for money to play a factor, all fusion research should be available to every engineering group around the world.

By Captain Orgazmo on 2/15/2014 4:40:54 PM , Rating: 1
The impetus for just about every major scientific breakthrough came from the promise of personal gain. Competition for prestige and money are far better drivers of innovation than abstract and questionable socialistic ideals. Accidental discovery and nationalist-military need are the other mothers of invention.

It all comes down to human nature, the thing that the liberal-socialist rulers exploit, and liberal-socialist followers can't even comprehend.

In any case, why share with say China? They plan everything for their gain at the detriment of everyone else. National-level altruism is an entirely new, and solely Western affliction.

50 years from now...
By typicalGeek on 2/15/2014 4:06:32 PM , Rating: 2
50 years from now Tesla Motors will put a miniature one of these in their cars in place of the battery pack. And when Daily Tech announces it the first half dozen comments will be noise about how it's much better for the environment to refuel an ICE vehicle every 500 miles than having one that requires a few grams of hydrogen isotopes every 10 years.

RE: 50 years from now...
By CBRworm on 2/20/2014 12:40:58 PM , Rating: 2
...and the next few comments will be asking why DT is doing car reviews...

By Amiga500 on 2/15/2014 8:58:08 AM , Rating: 2
"While some physicists remain convinced that mankind may not ever be able to harvest reliable power from direct nuclear fusion reactions"

Not slighting on the author, but I'd be interested to see who these people are?

[more or less to slight on them!!]

A couple of examples where very well educated people reasoned that things couldn't be done:

In the early 1940s, some physicists believed the sound barrier to be just that... a barrier through which no human could go.

Others (notable) people believed (in the 1930s) you could never put a jet engine on an aircraft... it would weigh thousands of tons.

"There is a single light of science, and to brighten it anywhere is to brighten it everywhere." -- Isaac Asimov

Most Popular Articles5 Cases for iPhone 7 and 7 iPhone Plus
September 18, 2016, 10:08 AM
Automaker Porsche may expand range of Panamera Coupe design.
September 18, 2016, 11:00 AM
Walmart may get "Robot Shopping Carts?"
September 17, 2016, 6:01 AM
No More Turtlenecks - Try Snakables
September 19, 2016, 7:44 AM
ADHD Diagnosis and Treatment in Children: Problem or Paranoia?
September 19, 2016, 5:30 AM

Copyright 2016 DailyTech LLC. - RSS Feed | Advertise | About Us | Ethics | FAQ | Terms, Conditions & Privacy Information | Kristopher Kubicki