Two-laser boron fusion lights the way to radiation-free energy | Hacker News Reader

Two-laser boron fusion lights the way to radiation-free energy

nature.com

79 pointsfeelthepain35 comments

Readers may be left wondering…

• How many protons and nuclei did they have to fling to get one to hit?

• How much Boron-11 is there accessible on the planet?

• How much energy is released, relative to energy required isolate Boron-11, turn it to plasma and generate a proton stream? (Not in this setup, but could this ever be used for energy production?)

• Are there other isotopes to which this proton bombardment technique could apply?

1) They were creating a plasma from a sheet of boron and sending the protons at that. From the publication: "1 in 300–3,000 protons will be able to induce a p11B fusion reaction".

2) There seems to be a fair but not infinite amount: http://www.rsc.org/periodic-table/element/5/boron. One site listed $500 per 100g.

3) It doesn't seem that such a calculation is readily available. However, now that the physics has been demonstrated, one can start to entertain such questions. Also, we are continually improving the efficiency of our laser sources, so as those improve the energy cost for this setup decreases.

4) Also from the publication: "Although our results are speciﬁc to the p11B case, a similar approach could be used to study the reaction of other light isotopes."

Bonus: Actual publication link (I'm not sure if the link is paywalled): http://www.nature.com/ncomms/2013/131008/ncomms3506/full/nco...

2) There is a lot of Boron 11, it makes up 80% of Boron.

3) Yes! You can use this for energy. In fact see my other post - I believe this is the future of fusion. The Boron doesn't need to be a plasma, so you don't need to confine it. You just leave it as a solid and hit it with protons.

4) You can also use Lithium (both isotopes) and Nitrogen (the rare 15 one).

What's more notable is that you can directly convert this to energy - the reaction yields charged particles, which will cut flux and induce current.

Simple compounds of boron used in soapmaking and household cleaning sell for order ~$1 per kg. If you can't make isotopically pure Boron 11 for under $10 per kg in bulk out of such products in far greater quantities than could ever be used in fusion, I would be very surprised.

For perspective, I figured out recently that one 76-oz box of Borax has enough fuel to power 150 average American homes for a year: http://focusfusion.org/index.php/forums/viewthread/1261/

I don't know how much energy is required to isolate Boron-11, but certainly it'd be a lot less than that. Since it's a light element it'll be relatively easy to centrifuge.

Energy output vs energy input in the reactor itself is always the big challenge for fusion. This experiment put more energy in than they got out, just like all other fusion experiments so far.

However, previous papers on boron fusion using petawatt picosecond lasers have estimated a 10,000x energy gain, once we have sufficiently powerful lasers (about an order of magnitude better than we have currently). See the references section here: http://www.climatecolab.org/web/guest/plans/-/plans/contestI...

2) It's a very rare [1] and expensive material, but has lots of awesome properties. There is only a little boron on earth and 63% of that is in Turkey, many have died fighting against outselling it there, but politicians sealed the international deals anyway, that's a widely ignore fact.

It is a low-abundance element in both the solar system and the Earth's crust.

Somebody should invest a lot of money and time into finding synthetic Boron, because I really believe into this technology. Without synthetic Boron, it's a waste of very rare resources that we have on our earth crust.

Side note: Interestingly there was even a "reference" to Boron known as Boronite in Star Trek that could be synthesized into one Omega Molecule that looked like a Fullerene [2]. The Omega molecule was known to be the most powerful substance known to exist.

[1] http://en.wikipedia.org/wiki/Boron

[2] http://en.wikipedia.org/wiki/Fullerene

We really ought to be investing more broadly in fusion technologies. Please spread the word to scientists that they can back this recommendation if they agree. http://lawrencevilleplasmaphysics.com/index.php?option=com_l...

Supporting broader funding will increase the richness of the science in the field, which gives us more angles to understand what works and what doesn't. I support funding an array of approaches instead of going all-in on ITER that seems to have no future, but I'm not a professor.

ITER seems to be the best bet that can get financed currently...

ITER is a mess. It's a stereotypical government program that will do little to advance fusion science and will take so long to build and be so expensive that it will be of questionable value even if they manage to finish it.

ITER is crazy expensive unlike the project linked above which has spent about $1 million total. Tokamak designs have been around for decades and still have not achieved commercial viability. I think ITER is a long shot at best. Lawrenceville Plasma Physics seems to be much farther along than some of the other well-funded projects.

Of course, who knows who will do it first and when. I sure don't. But we should be funding as many possible designs as we can not less.

This is the future of fusion, not D-T fusion. Or use Lithium instead of Boron.

Lithium is even better than Boron because you don't need isotope separation (since both work), and you get more power out of it.

The Boron or Lithium doesn't need to be a plasma, and you don't need to confine it. This makes it much simpler to handle.

You leave it as a solid and just hit it with protons. Not all the protons will do anything. If you can recycle the energy of the failed protons then the low efficiency can be mitigated.

Those that hit will leave behind helium (both H3 and H4) you probably need to remove that to prevent interfering with incoming protons. But there is no other ash to worry about. (And the H3 is very useful - you can even use it for energy.)

I'm confused as to why it would leave behind h3 and h4?

Mass is conserved in nuclear fusion.

p+Li6 fusion is a single proton (a bare hydrogen nucleus) smacking into an atom made of 3 protons and 3 neutrons. (Lithium-6) The reaction products have to have the same number of protons and neutrons as what goes in.

I meant He3 and He4, sorry.

Aneutronic, not radiation free.

It's emitting alpha particles, but the energies are pretty low.

I assume you meant emitting. Omitting alpha particles isn't a problem.

Yes, but that's very important. Alphas, especially slow ones, are easy to stop and are good at heating things. Free neutrons are hard to stop and can activate nearby material. An a-neutronic process, especially a clever one that works with comparatively low energies, can be important.

Sure, if there was no radiation at all, it'd be utterly useless.

And since alphas are charged particles, you may even be able to generate electricity without going through a steam cycle. Tri-Alpha and Lawrenceville Plasma Physics are both planning to do it that way, and papers on petawatt laser fusion with boron have mentioned the same. Resulting energy costs could be dramatically cheaper than fossil.

I was about to ask about this, because I thought someone proved that it was impossible to get enough energy from aneutronic reactions, and the neutrons cause nuclear activation, which in turn makes the reaction a lot less clean than we'd like.

The resulting heat could be used to reduce boria to elemental boron, which makes a decidedly energy dense fuel:

http://www.eagle.ca/~gcowan/boron_blast.html

After reading the full text article I was surprised to find the protons from the aluminium foil/picosecond pulse interaction actually come from hydrocarbon impurities that were on the back surface of the foils.

If they don't guard that hydrocarbon film on the back of the aluminium from the Boron-ionizing nanosecond pulse then they don't get protons. So that is why the second thinner aluminium film is there; to shield the impurity layer on the thick aluminium film.

I would like to say that contrary to software engineering, physical engineers tend to use quirks more often than software engineers, but the reality is that in both worlds quirks are heavily used and accepted. Hence MVP and other quick and dirty delivery models are popularized...

Lies! It's not radiation-free because light and heat was generated (and thus radiated)!

When it's mentioned in the "potentially harmful" scope, "radiation" is shorthand for ionizing radiation.

Yet there's no shorthand for the "potentially beneficial" scope...

I just hate that the general public connotes "radiation" with "harmful".

> Yet there's no shorthand for the "potentially beneficial" scope...

Yes there is. The main word is "light". And also "warmth" or "radio waves".

... and X-rays, radiotherapy, scintigraphy...

Still, the fact is that "radiation", for the layman, means nocive radioactivity.

p-B11 fusion would be the holy grail for energy, since ordinary Hydrogen is very common, Boron-11 is the most common isotope, and Boron itself is fairly common on Earth (annual production is around a million tonnes). Moreover, the reactor design could be remarkably simple and highly efficient. Power could be directly converted from the plasma to electricity without a need to use heat exchangers or steam turbines. Additionally, the low neutron flux would make the reactor remarkably safe, as would the fusion products (primarily ordinary Helium).

However, as far away as D-T fusion energy is today p-B11 is even farther. p-B11 fusion requires plasma temperatures 10 times higher than D-T fusion, making it that much more difficult to build devices capable of inducing fusion. Worse yet, at those conditions the bremsstrahlung radiation loses using conventional plasma confinement technologies would be significantly higher than the power produced by the fusion reactions. What that means is that for every watt produced by fusion that might be converted to a fraction of a watt of useful power there would be more than a watt of power radiated away in x-rays and gamma rays, meaning that it would cool faster than it could be heated by fusion energy, rendering it useless as a power source.

In short, p-B11 fusion requires the development of novel approaches to plasma confinement and ramping up their capabilities up to and orders of magnitude beyond what we've done with tokomaks et al today. To say that this would be an enormously challenging scientific and technical enterprise would be a gross understatement.

Nevertheless, it very much does warrant continued research. No matter the difficulty there's no way to get to a destination without spending the time on the road there.

All true but several groups are attempting it. LPP has published a paper in Physics of Plasmas showing they'd reached 1.8 billion degrees C, well over the minimum required for boron fusion. They claim that bremsstrahlung is suppressed at the extreme magnetic fields they generate, and that this effect is well-known to astrophysicists.

There are also papers claiming that side ignition of boron fuel is possible with a 60-petawatt picosecond laser, about six times bigger than our largest today. Tri-Alpha is also attempting boron fusion: http://nextbigfuture.com/2013/06/tri-alpha-energy-review.htm...

The perspective to keep in mind is "attempting" is the same thing we're doing with a lot of these things. I wouldn't want to be picking winners yet.

Yes and I think most people researching alternative fusion methods would agree. The LPP guys certainly do.

It's arguably unfortunate that we picked tokamaks as the winner quite a while ago. LPP is trying to get scientists to sign a letter supporting a broad range of research, from other approaches to tokamaks (like the recently-cancelled Alcator C-Mod) to completely different devices. Several promising projects were cancelled in 2011, like MIT's levitated dipole, and non-tokamak approaches have struggled to get funding for decades.

http://www.lawrencevilleplasmaphysics.com/index.php?option=c...

What about a three-laser system?

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