Slashdot Mirror
Laser Fusion's Brightest Hope
First time accepted submitter szotz writes "The National Ignition Facility has one foot in national defense and another in the future of commercial energy generation. That makes understanding the basic justification for the facility, which boasts the world's most powerful laser system, more than a little tricky. This article in IEEE Spectrum looks at NIF's recent missed deadline, what scientists think it will take for the facility to live up to its middle name, and all of the controversy and uncertainty that comes from a project that aspires to jumpstart commercial fusion energy but that also does a lot of classified work. NIF's national defense work is often glossed over in the press. This article pulls in some more detail and, in some cases, some very serious criticism. Physicist Richard Garwin, one of the designers of the hydrogen bomb, doesn't mince words. When it comes to nuclear weapons, he says in the article, '[NIF] has no relevance at all to primaries. It doesn't do a good job of mimicking secondaries...it validates the codes in regions that are not relevant to nuclear weapons.'"
Even if it was igniting and had good fusion gain, there are such a huge array of serious engineering issues that they have got no economic answers for that it is never going to work commercially. High precision optics in close proximity to nuclear blasts?? High precision targets that cost $10k (but would have to reduce to $0.25 to be commercial) being introduced into a plasma filled chamber at 15Hz that must be positioned with sub mm precision? May as well keep it running now for the materials side of things, but as much as possible fusion R&D budgets should be directed away from NIF and ITER (tokomaks are too big and too expensive to be commercially viable) and towards fusion options with at least some potential for commercial viability like:
General fusion (liquid metal implosion on plasma target), Tri-Alpha, Helion (electromagnetic compression of plasma toroids), Polywell (Inertial electrostatic confinement in a magnetised 'wiffleball' trap).
Also Fission in fast breeders provides a far more certain short term payoff, cheap, managable engineering issues, no nasty tritium to deal with and massively reducing radioactive waste compared to current non-breeding reactors. There is enough accessible Thorium and Uranium to power our civilisation at current levels until the sun kills the earth.
"That makes understanding the basic justification for the facility, which boasts the world's most powerful laser system, more than a little tricky."
NIF is a way to keep scientists at LLNL employed. That is its #1 justification, and always has been. Ask any insider.
Any hope of laser-based fusion is a pipe dream, and always has been. Nuckolls himself, the guy that started all of this, was shown a calculation in the early 1970s that proves this beyond a doubt. The problem is that the price of the target is many many times the value of the electricity it could produce.
Power on the grid right now is selling for about 3.3 cents a kWh. (see http://www.ieso.ca/imoweb/marketdata/markettoday.asp)
NIF, if it worked, which it doesn't aims to produce about 20 MJ a "shot". Under good conditions you might convert 25% of that to electrical power (don't quote gas peaker efficiencies, they're a different cycle). So we might get 5 MJ per shot.
If you're not familiar with MJ, it's a measure of energy. kWh is a more common one, so I'll convert 5 MJ = 1.39 kWh.
So at current prices, each shot might produce about 5 cents worth of power.
Now simply look at the target. It's a gold-covered cylinder machined to the sixth decimal place accuracy, capped on it's open end by double-pane windows of some incredibly clear optical system, inside of which is an equally perfectly machined plastic sphere containing the fuel that's cryogenically frozen on the inside and then smoothed using an IR laser.
The targets costs thousands and thousands of dollars per shot. And might (if it ever works) delivers a few cents of power. See the problem?
When this was first pointed out to Nuckolls in the early 1970s he worried, and then ignored it. He proposed a system with such high gain that the fuel would be delivered from a perfume mister that would self-form through surface tension into a ball that would be close enough for comfort.
We've spent 40 years learning about the physics of ICF, and what we've learned is that there is absolutely no way this could possibly work. The physics just isn't there. So instead we've pushed ahead with ever less-cost-efficient machines with ever-less-convincing excuses for doing so. Nova, built in the 1980s, was only 2-fold less successful in reaching break-even than NIF. However, NIF costs well over 10 times as much. The price efficiency is *dropping* with every generation.
A lazy and ignorant comment.
You don't know anything about Richard Garwin, clearly. Nor do you understand how Federal funds are allocated. I could go on but that is already a lot of stupidity packed into one sentence.
Richard Garwin is the most distinguished defense scientist in the U.S., and provides scientific advice to the government (like the advice quoted in TFA). At age 85 he is unlikely to be cooking up any billion dollar projects of his own.
Starships were meant to fly, Hands up and touch the sky - Nicky Minaj
The bad news is that this has been the case since the 50s. Given the track record of fusion power, I wouldn't hold my breath. Given the rate of climate change we better develop other options fast.
putting the 'B' in LGBTQ+
Richard Garwin is the most distinguished defense scientist in the U.S., and provides scientific advice to the government (like the advice quoted in TFA). At age 85 he is unlikely to be cooking up any billion dollar projects of his own.
Are you *absolutely* certain that in the course of performing top secret nuclear experiments for the government, he hasn't become a power-hungry immortal mutant?
Ezekiel 23:20
... and it always will be." - old saying.
As a counterbalance: Clarke's Three Laws:
1. When a distinguished but elderly scientist states that something is possible, he is almost certainly right. When he states that something is impossible, he is very probably wrong.
2. The only way of discovering the limits of the possible is to venture a little way past them into the impossible.
3. Any sufficiently advanced technology is indistinguishable from magic.
Prove anything by multiplying Huge Number times Tiny Number