

Two-laser boron fusion lights the way to radiation-free energy - feelthepain
http://www.nature.com/news/two-laser-boron-fusion-lights-the-way-to-radiation-free-energy-1.13914

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jws
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?

~~~
rubidium
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](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...](http://www.nature.com/ncomms/2013/131008/ncomms3506/full/ncomms3506.html)

~~~
ars
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).

~~~
XorNot
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.

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knappador
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...](http://lawrencevilleplasmaphysics.com/index.php?option=com_lyftenbloggie&view=entry&year=2013&month=09&day=23&id=105%3Aopen-
letter-on-fusion&Itemid=90)

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.

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

~~~
rpedela
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.

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ars
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.)

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

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sbierwagen
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.

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meepmorp
Aneutronic, not radiation free.

~~~
ISL
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.

~~~
DennisP
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.

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samatman
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](http://www.eagle.ca/~gcowan/boron_blast.html)

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superkuh
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.

~~~
X4
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...

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ch4ch4
Lies! It's not radiation-free because light and heat was generated (and thus
radiated)!

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

~~~
ch4ch4
Yet there's no shorthand for the "potentially beneficial" scope...

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

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

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

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

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

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InclinedPlane
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.

~~~
DennisP
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...](http://nextbigfuture.com/2013/06/tri-alpha-energy-review.html)

~~~
XorNot
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.

~~~
DennisP
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...](http://www.lawrencevilleplasmaphysics.com/index.php?option=com_lyftenbloggie&view=entry&year=2013&month=09&day=23&id=105%3Aopen-
letter-on-fusion&Itemid=90)

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electronous
What about a three-laser system?

