

Lawrence Livermore NIF laser fusion experiment delivers record energy output - UnFleshedOne
http://www.powersystemsdesign.com/lawrence-livermore-nif-laser-fusion-experiment-delivers-record-energy-output

======
gwern
I spent a bit of time over the last 3 months typing up & annotating an obscure
but excellent SF/literary novel, _Radiance_ by Carter Scholz (
[http://www.gwern.net/docs/2002-radiance](http://www.gwern.net/docs/2002-radiance)
). It's all about the Lawrence Livermore SDI scandals and then the process of
them getting NIF, so I read up on the historical background.

I was a little flabbergasted at the overall progress of the laser fusion
research program: apparently back in the early '70s, the first LANL people
predicted that you could achieve laser fusion with just 1kj of input. Millions
were spent, ignition was nowhere near, so they got funding for another, bigger
laser, which failed too, so they got funding for more lasers, and those failed
too, so they got funding for an even bigger multi-billion dollar laser called
NIF, and not only has that failed to reach ignition once as promised - despite
going up to 1.7mj (quite a long way from 1kj) - LANL managed to run over
budget by at least 400% and took something like a decade longer to finish NIF
than promised!

~~~
dhbradshaw
In the top paragraph you mention Lawrence Livermore and in the bottom one you
use the acronym LANL, which is Los Alamos. Did you mean LLNL?

~~~
gwern
Yes, my bad. (They're so damn similar acronyms >.<)

------
cjensen
NIF has been around so long that the digitizer scene in the original TRON was
filmed there. Its purpose is to explore the physics of exploding nuclear
weapons; it is an arm of the lab which designs US nukes.

Any similarity between NIF and a practical Fusion Reactor is purely
accidental.

~~~
ballard
Yup.

TL;DR - More money -> likely fewer results.

Large organizations tend toward waste, delay and mediocrity. Without a profit
motive and a mission to deliver a specific solution, the modus operandi is to
grow as big of a budget pyramid as possible while providing just enough press
releases to keep the DOE gravy-train rolling.

This is why high beta and other approaches from smaller groups may likely
crack the problem, despite not having all of the toys (and distractions).

~~~
hellgas00
What a ridiculous comment. Large budget in comparison to what? So the
scientists who have dedicated their academic lives to research are just in it
for the money? Does NASA waste the $16.6 Billion they receive? The Saturn 5
was developed for hundreds of billions. There is absolutely nothing that would
substantiate your "gravy train" buzz phrase.

~~~
ballard
Duh. NASA wastes billions for the value delivered, and it's more/less an
Amtrak. SpaceX, Virgin Galatic and Stratolaunch deliver much more value
because they have to; hence vendor partnerships and [0]. NASA, along with the
rest of USG, is also trying its best to manage a multitude of
accelerator/incubator programs to promote private, commercial research.

Saturn V might have worked, but justifying costs of one program with historic
waste of another is still an invalid argument in the context of cost of
success.

[0]
[http://www.nasa.gov/pdf/169943main_NASA_Virgin_Galactic_MOU....](http://www.nasa.gov/pdf/169943main_NASA_Virgin_Galactic_MOU.pdf)

~~~
hellgas00
"Saturn V might have worked, but justifying costs of one program with historic
waste of another is still an invalid argument in the context of cost of
success." Did you read your comment? You can't justify your argument by
bringing up "Amtrak" (not sure what an Amtrak is) a supposed failing
enterprise, as much as I can bring up the Saturn V and use it to support my
point. Again there is absolutely nothing to back up what you said. The issue
of wasted costs comes down to management and little else. Small business and
large businesses both can waste money or apply capital in smart ways. You also
didn't specify what a large amount of money is, is Apple more wasteful than
Boeing because of the disparity of income? The amount that NASA gets in
funding is quite small and they do a lot with it. SpaceX or Virgin Galatic
aren't actively commanding multiple missions within and outside of our solar
system. Your argument is so general and naive. Have you ever worked in
industry?

------
drjesusphd
I don't know why they're even pretending anymore. Everyone knows NIF is a
weapons research facility and always has been. They've milked all the PR
they're going to get out of this.

------
quanticle
Did this get a positive energy return? If I've understood past ignition
attempts correctly, they too delivered tremendous energy output... but
required even more tremendous energy input.

~~~
throwaway_yy2Di
No, it's extremely negative.

 _" In the nanoseconds that followed, the capsule imploded and released a
neutron yield of nearly 3x10^15, or approximately 8,000 joules of neutron
energy..."_

 _[...]_

 _" These promising returns were the result of a laser experiment that
delivered 1.7 megajoules (MJ or million joules) of ultraviolet light..."_

More numbers:
[https://en.wikipedia.org/wiki/National_Ignition_Facility#NIF...](https://en.wikipedia.org/wiki/National_Ignition_Facility#NIF_and_ICF)

~~~
nonce42
To put these numbers in context, 8000 joules is about 2 kilocalories (or about
half an M&M candy). It's about $0.0003 of wall electricity. It's about the
energy in an AA battery. It's the energy from exploding 2 grams of TNT.

1.7 megajoules is about 400 kilocalories, or a king size Kit Kat bar. This is
the energy of a car going 140 miles per hour. This is about 7 cents of AC
power.

~~~
PhasmaFelis
_"...about 400 kilocalories, or a king size Kit Kat bar. This is the energy of
a car going 140 miles per hour."_

Wow. How can those two things be equivalent? I know there's a lot I don't know
about physics...

~~~
Florin_Andrei
Kinetic energy is the speed, squared, times the mass, halved.

140 mph is not a small number; to the power of two it's rather large. Now
multiply the result by the mass of a car, which is still pretty huge even
halved.

A racing car barreling down the speedway packs a hell of a punch.

~~~
StavrosK
I think the GP's question was more like "how the hell can a single Kit Kat bar
get a whole car to 140 mph?".

~~~
Florin_Andrei
I see.

Well, a kitkat bar actually has a decent amount of energy in it. Very roughly,
the same energy as the same mass of wood, or gasoline. Chemical fuels don't
vary too much in terms of energy density. They stay within the same order of
magnitude, at most.

And yes, food is chemical fuel.

~~~
maaku
No, a Kit Kat bar has _way_ more energy per gram than wood, or even TNT. A
king size Kit Kat bar packs basically the same energy as 0.5kg of TNT. That's
a lot of power.

Probably only a straight-up chemical fuel like gasoline or methane packs more
punch per gram.

~~~
gus_massa
Strange. I did some research and found some numbers.

The energy density of Kit Kat is 22 MJ/Kg (5.2 Kcal/g)
[http://www.wolframalpha.com/input/?i=%28Kit+Kat+calories+to+...](http://www.wolframalpha.com/input/?i=%28Kit+Kat+calories+to+megajoules%29+%2F+%28Kit+Kat+weight+to+kilograms%29)

TNT has 2.8 MJ/Kg in an explosion and 4.2 MJ/Kg in a combustion. It has too
much Carbons. In an explosion, it doesn’t react with the oxygen in the air,
because it’s too fast. There is an interesting discussion in
[http://en.wikipedia.org/wiki/Trinitrotoluene#Energy_content](http://en.wikipedia.org/wiki/Trinitrotoluene#Energy_content)

In general, the explosives have to explode without using the Oxygen in the
air, so they have a lot of Oxygen and Nitrogen atoms inside. The fuels for
slow combustions can have almost only Carbon and Hydrogen atoms to store the
energy more efficiently and get the Oxygen from the air.

Nitroglycerin has less Carbons, so has more energy density. Mixed in dynamite
has 7.5 MJ/Kg and alone has 6.4 MJ/Kg (Is this correct? I expected a bigger
value).

I found a list of these values for a wide range of materials. In particular it
says that green wood has 10 MJ/Kg, air dry wood has 15 MJ/Kg and oven dry wood
has 20 MJ/Kg. [http://physics.info/energy-
chemical/](http://physics.info/energy-chemical/)

Other values: Gasoline ~45 MJ/Kg, Methane 55.5 MJ/Kg, Hydrogen 142 MJ/Kg

------
VladRussian2
with extremely low efficiency of lasers, my bets is on Sandia Z machine.

Not that these guys are in any rush to produce practical reactor as they are
also mostly nuke weapons research, yet as a side effect they have been making
very interesting and meaningful progress during last 15 years. The machine
itself isn't for fusion research, it is for X-ray generation, and it just
happens that it generates so much and so efficiently that it seems they
couldn't resist and finally started trying mini Teller-Ulam :)

------
chaosphere2112
Link to the original press release:

[https://www.llnl.gov/news/newsreleases/2013/Aug/NR-13-08-04....](https://www.llnl.gov/news/newsreleases/2013/Aug/NR-13-08-04.html)

------
ballard
TL;DR - 3 orders of magnitude from economic viability.

in 1.7 MJ

out 8 kJ

Q = 0.00444_

~~~
drjesusphd
Compare that to 5 MJ _output_ from JET, at an efficiency of 65%.

~~~
ballard
Yup. JET is delivering much than NIF, in terms of reaching the goal of
maximizing Q.

NIF has a program cost (1997-2013) on the order of $8B USD to reach this
unimpressive number. (Based on $450m/yr not including fixed/one-time costs.)

JET is in for about $20B USD ($15B €). [0]

JET might be around thrice as costly, but the results speak for themselves.

[0] [http://www.efda.org/fusion/why-should-society-invest-in-
fusi...](http://www.efda.org/fusion/why-should-society-invest-in-fusion-
research/cost-of-fusion-power/)

------
contingencies
Cultural observation: some serious govspeak interleaved with respectful
capitalisation of 'Mother Nature'.

(At least if the world disappears due to a crazy physics experiment one day,
metaphysical archaeologist sensors in some parallel dimension who became aware
of the event might see that we weren't entirely disrespectful!)

~~~
drjesusphd
WTF are you talking about?

