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Two-Laser Boron Fusion Lights the Way To Radiation-Free Energy
ananyo writes "Fusion unleashes vast amounts of energy that might one day be used to power giant electrical grids. But the laboratory systems that seem most promising produce radiation in the form of fast-moving neutrons, and these present a health hazard that requires heavy shielding and even degrades the walls of the fusion reactor. Physicists have now produced fusion at an accelerated rate in the laboratory without generating harmful neutrons (abstract). A team led by Christine Labaune, research director of the CNRS Laboratory for the Use of Intense Lasers at the Ecole Polytechnique in Palaiseau, France, used a two-laser system to fuse protons and boron-11 nuclei. One laser created a short-lived plasma, or highly ionized gas of boron nuclei, by heating boron atoms; the other laser generated a beam of protons that smashed into the boron nuclei, releasing slow-moving helium particles but no neutrons. Previous laser experiments that generated boron fusion aimed the laser at a boron target to initiate the reaction. In the new experiment, the laser-generated proton beam produces a tenfold increase of boron fusion because protons and boron nuclei are instead collided together directly."
Hooray! Fusion power is now only 20 years in the future! The absence of fast neutrons really is a breakthrough, though: the less radioactive a reactor itself becomes over time, the easier the cleanup at the end of its life.
Socialism: a lie told by totalitarians and believed by fools.
This experiment sounds like the first step in the practical small scale direction since Farnesworth's fusor was developed into a commercial neutron source for hospitals and oilwells.
Well, nuclear reactions that we can turn off like laser-initiated fusion are a lot nicer than the alternatives. The inside of your car engine is a raging inferno shot with electric sparks and compressed with inexorable steel cylinders. That doesn't keep you from going on a nice drive with your sweetie.
Bruce Perens.
Robert Bussard's fusion project at Energy Matter Conversion Corporation was aimed at investigating Proton-Boron fusion, because it is clean and produces no high-energy neutrons. I was really hoping this was a follow-on to that work. The device Bussard called a Polywell actually shows some serious potential to revolutionize nuclear power globally. It even shows enough promise that the US Navy has been funding some small-scale experiments. It's unfortunate that Bussard died before he could see the potential of the Polywell realized, but it would be nice to see it succeed none the less.
Reinvent the wheel only at either a lower cost, greater effectiveness, or your own personal enrichment and satisfaction.
There was something called "focus fusion" that utilized boron-hygrogen fusion but I'm not sure it did work out well. Regardless, I'm less and less confident if it makes sense. Solar cells and wind turbines are becoming cheaper every year and have passed nuclear energy cost (in $/kWh) some time ago (was it 2010? I don't remember...). Like computers, those devices are becoming cheap commodity and are on their way to take carbon in terms of dollars per kWh. In other worlds, renewables (along with smart grids and energy conservation techniques) are on their way to become new "traditional" energy sources. Bucky Fuller was right after all: nuclear energy (in all its forms) is only marginally better than fossil fuels, renewables take the play to whole new level. We've just missed it for some time because fossil was too cheap (to be frank - partly thanks to stealing fossil fuels from 3-rd world countries by western powers)
Having said that, it does not mean we shouldn't do any research in this area. Basic research is THE basis of achievements of our civilization but please call spades the spades. Don't think it will magically solve our energy problems but there is a chance it will become breakthrough in many ways we don't expect.
When Boron releases a helium nuclei, isnt it fision then?
The lack of neutrons in this reactions is nice, but the protons and boron nuclei still need to overcome the Coulombe barrier. Generating practical fusion power still needs a combination of pressure, temperatures and containment times that have not yet been achieved in fusion machines. Accelerator base fusion works (for p-B, or hydrogen, but too many of the particles scatter rather than reacting so you can't reach break even.
This scheme sounds nice for R&D, but not at all clear that it can lead to break-even
Almost certainly what the summary/title is trying to say is that the new technique does not make its surrounding radioactive, i.e. that once the fusion reaction stops, so does the radiation.
This is the popular / layman's idea of 'radiation' - an inimical influence that cannot be removed from its host material.
I thought collecting interstellar hydrogen atoms with giant magnetic scoops while accelerating to near lightspeed and using them in a fusion ramjet was what Bussard was working on...
The guy was profligate! He had at least two ideas over the span of his career!
[End sarcasm] I wish I didn't believe that was needed.
Sure I'm paranoid, but am I paranoid enough?
... then its even higher pressures involved, where the fuel explodes instead of burns.
For anyone that wonders: french research agency CNRS has thousands of small research teams, which are each commonly led by a research director. A CNRS research director is like a university professor, except he/she is not in charge of any teaching.
It's not a problem, it's an advantage.
You get a 3X +2 Helium nucleus (aka alpha) at 8.7 GeV. Since the particles are charged, you can convert their energy to a usable electrical current directly. (Think field windings of a generator, except there is no winding, just a moving charge.) Neutrons have the disadvantage of _requiring_ a thermalization process to capture their energy.
The disadvantage of the alpha is that it is _easily_ thermalized. You need to keep everything out of it's way until you can extract its energy. This implies super deep vacuum, or a super tiny machine so that the energy conversion device is within the slowing down length of the alpha. The slowing down length of an alpha in air is on the order of a centimeter, IIRC.
Of course, I'm assuming that direct conversion is superior to thermal conversion. If thermal conversion is superior, then just thermalize the alpha just like a neutron, in a big tub of water. Just make sure your tub is grounded to prevent charge buildup.
Almost certainly what the summary/title is trying to say is that the new technique does not make its surrounding radioactive
I agree, but it's worth mentioning that it's not that huge of a problem with the existing systems. If you've ever been to a tokamak, the inside is lined with copper. The neutrons do make the copper radioactive, but just a little bit, and it's back to normal copper in a few decades.
It's more of a maintenance downside than it is one of nuclear waste - if the copper gets too radioactive, it becomes harder to maintain the plasma.
My God, it's Full of Source!
OUTSIDE_IP=$(dig +short my.ip @outsideip.net)
That doesn't keep you from going on a nice drive with your sweetie
To be fair, it's fairly difficult to drive one handed.