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Friday, September 21, 2012

LASER FUSION

This is Part 3 in my series on fusion.  My favorite option is laser fusion, probably because after gaining my PhD building a tunable laser before one could be purchased, I went on to become a faculty member of the University of Hawaii, spending my first summer assignment forty years ago at the Lawrence Livermore National Laboratory (LLNL) as a staff member of the laser fusion team under Edward Teller.  LLNL is a science lab, where physicists dominated.  As an engineer, I was a second class citizen, for we were there to serve the masters.  Back in those days no one could yet envision what type of laser would be used for the ultimate commercial facility.  Four decades later, they still have no firm idea on this important detail.  


It can be said that our nation is covering ourselves by participating in the ITER magnetic confinement effort (see previous posting), while harboring hopes for the National Ignition Facility (NIF, above) at LLNL.  Here is the fusion budget:


It cost $3.5 billion to construct NIF, with 192 laser beams.  However, for fiscal year 2013, the project will receive only $84 million, $26 million less than last year.  In short, the Feds have warned LLNR, get net positive this coming year or face further cuts.  This is an important point I haven't yet mentioned:  NO FUSION TECHNOLOGY HAS YET ATTAINED NET POSITIVE ON PLANET EARTH.  This will become the first...if it succeeds.  Project staffers are hopeful that this epochal achievement will happen this (coming?) year.  When I last year predicted that the Higgs Boson would be found in August of this year, I also indicated that LLNL would succeed last month.  Let me adjust my wild guess by giving them until January 2013, thus beating ITER by about a dozen years.

What will NIF do?  It will zap a tritium droplet (1 mg, with a diameter less than human hair) for a few trillionths of a second.  The temperature created will exceed 100 million Kelvin (180 million degrees Fahrenheit) and density 100 billion times as we currently face on the surface of our planet.  You thought those ITER conditions were extreme?  Here, because crucial inertial confinement requirements must be made, the pressures are extraordinary.  This special environment has only previously been attained by the Big Bang nearly 14 billion years ago and the centers of exploding H-Bombs and stars.  Still, NIF does not have enough oomph to create a Black Hole.

I should add that there are several other countries advancing laser fusion development.  To be commissioned any day now is the French Megajoule near Bordeaux (left), about the same power, with 240 beams.  The Russian version is still a decade away, but will be at least 50% larger than the LLNL laser.  China, South Korea and Japan also have active programs.  I love the names picked:  Divine Light (China), Orion (U.K.) and Gekko (Japan).  

One more facet of laser fusion is that in some countries (you can guess which ones), the nuclear weapons potential of this Death Ray is obvious.  In our country, this now goes by the term, nuclear stockpile stewardship.  It is possible that the primary motivation of laser fusion might well still be related to military needs.  However, it might be fortunate that there is some defense component to laser fusion, for this support only advances the potential for the peaceful applications of fusion.  Plus:

For a good few years now, nuclear fusion has looked like offering a solution to the problem. For every 100 tonnes of coal we burn, fusion has the potential to deliver the same amount of energy, without any carbon dioxide emission, using a small bath of water and the lithium contained in a single laptop battery. Moreover, it would be inherently very safe and would not produce any significant radioactive waste. Lest there be any confusion, the science behind this way of harnessing the energy locked away inside the atomic nucleus is entirely different from that used in current nuclear fission reactors. It almost seems too good to be true … but it isn't.

Like ITER, NIF is just a step towards commercialization.  The next one will be a Laser Inertial Fusion Energy (LIFE, right) demonstration in the 2020's, firing 10-15 shots per second (NIF can only do 3 shots/day).  However, tritium is rare, not like deuterium, so LIFE will breed it's own tritium as part of the process.  The next step is expected to be 500 to 1000 MW commercial power plants by 2030.  While this is ridiculously optimistic, who knows, this is not impossible.

Let me end by editorializing on the budget of the U.S. Department of Energy.  Approximately $4 billion goes to energy R&D.  FISSION gets a little more than 41%, FUSION 21%, and the renewables 19%. However, energy is only 16% the budget of the USDOE.  Nuclear weapons dominate.  What is particularly depressing is that the Obama nuclear weapons budget, including inflation, is 15% higher than during the Reagan days while the Cold War was still on.  Finally:

There are two types of fusion: magnetic confinement (that donut or torus shaped machine, as being developed as ITER in France at a cost that is now expected to exceed $20 billion, just for the prototype), and inertial confinement, epitomized by laser experiments at our national laboratories. Both of these methods have undergone more than half a century of intensive research at a cost of more than $22.4 billion...and only in the USA. Look at it this way, we will spend three times more on the Stealth bomber just this coming year and this amount is only 72 days of the war in Afghanistan. Or, get this, $22.4 billion is one-fifth of Wall Street executive bonuses this past year!

This quote comes from one of my Huffington Post articles written just about a year ago:  Starpower for Humanity--heavy-ion fusion, the focus in Part 4 of my fusion series.  Are we, as a nation, taking Peak Oil and Global Warming seriously?  No.  The budget for WAR overwhelms.

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Tropical Storm Jelawat at 50 MPH seems to be headed straight for the Philippines at this point, but models predict a turn northward, increasing to at least a Category 3 typhoon by the middle of next week, skimming the northeast coast of the country, then a track towards Taiwan.


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