KSJ Tracker February 24, 2014

New Yorker: ITER reactor's instability. It's not just the plasma.

ITER Design Office/ for scale, a man stands near lower right

  Here's a long, remarkably detailed and deeply-reported yarn that is at heart a paean to the perseverence, dedication, and sheer perspiration of physicists and other designers of a monster project in Europe. Yet it will not be such good news for the supporters of the vital enterprise on which they are working:

 The subject, as even those who merely casually follow energy technologies will guess from the evocative hed, is fusion energy  - specifically, magnetically confined fusion and the long-planned and enormous International Thermonuclear Experimental Reactor. It has far to go but is now abuilding in France with tens of billions of dollars due before it's done from a mess of places including plenty from the US and with - by its charter - a Japanese director. The story is, first of all, a good piece of science writing by a New Yorker staffer who, while known for taking on tough jobs, does not do a lot of science. Savor the description right near the top of what is to go on in inside the toroidal or donut-shaped scene of action: "...a super-hot cloud of heavy hydrogen will rotate faster than the speed of sound, twisting like a strand of DNA as it circulates." Following that is a lot more about magnetic fields and other technical detail. But I had never though about tokamaks as containing a "rotating cloud." Sure, I'd read often that tokamaks have plasma currents circling around their donuts' axes. But I never thought of the motion as  Khatchadourian vividly describes it.

   (FYI. Just a week ago I posted on coverage of a step forward by the troubled National Ignition Facility in California, another whopping project but not quite ITER-sized in budget. NIF's operators hope to blaze a trail toward fusion-based electricity with a different method of slamming hydrogen isotope nuclei together: just whomp them in laser-driven implosions. That method is called inertial confinement as contrasted to ITER's magnetic confinement. Notable in NIF coverage recently, and almost always, was that few if any reporters mention ITER's existence. Ditto, unless I missed it in this very long story, Khatchadourian says nothing about inertial confinement and NIF as a rival effort. It's as though they are so distinct that reporters writing on one are too overwhelmed to see the other.)

   Before I get to the powerful theme of this long New Yorker story, a few quibblish notes on with how he handles the dense technnical info and history of magnetic confinment that he converted to damned good regular prose. 1) He credits in part to famous Russian physicist Andrei Sakharov and a colleauge, Igor Tamm, the origin of the tokamak design in the 50s. Essentially true, and I would never take Wikipedia's word over the New Yorker fact checkers' green light. However, Wiki does have on its article discussion page a declaration that the essence of the idea was in a letter to Stalin from a Soviet Army scientist-sergeant. The boss man turned to Sakharov to ponder it, so it says. 2) The article says "gravity is so crushing" in stars that light and heat take thousands of years to zig zag their way out. Well, it's the density of plasma in the sun's interior that sets up the obstacle course - a result of gravity of course but to just credit gravity is itself too opaque, 3) I just cannot picture the nature of what he calls the pedestal that can form at the outer side of the confined plasma and help to stabilize it.

   That said, this is a wonderful story. It depicts a super-expensive project that, at the level where the physicists and engineers are working, is severely underfunded. The harried brainiacs proceed with heroic efforts, but to read this no design milestones are reached without perilous shortcuts that evade full rigor. The multinational politics of the lines of authority are so tangled that the entire enterprise is as unstable as a plasma cloud itself, says here. At one point, he declared that pressure is so high, haste so frightening to behold, that "fear runs rampant." To read about the immense physical forces placed on the completed structure gives one the cold sweats. To read passages on the main US hardware contribution, a 1000-ton magnet inserted through the donut's hole (ie not inside the plasma chamber itself) is to come face to face with the possibility of failure almost everywhere in just this one element. And to learn that just to move the thing from General Atomics to port in Texas for shipment to France is to learn of the existence of such Brobdignagian things as trucks with 100 axles, so wide that they take up two freeway lanes and that must therefore  travel just around midnight. 

   Yet Khatchadourian does not overtly editorialize. He never says this 100-foot (30 m) high machine is doomed, no line like "why ITER cannot work." After all, it might. He clearly hopes it does. But as the author describes things the pressure to perform is so pervasive and oppressive within the project, the engineering challenges so daunting and the practical physics so meagerly understood, the margins for error so thin, that this reader easily imagines something dreadful going wrong long before they even get to making a switch with which to turn ITER on.

   But if ITER or some other path to fusion is not found in the next several decades, as the story explains, that will be dismal news indeed for the planet and human society. Throughout are lofty and effective passages, rich in description not only of machinery and physics but of the atmosphere around the project and its people trying desperately to succeed. It closes with reference to both Martin Luther King and to York Minster Cathedral. Wotta job.

Grist for the Mill: ITER site.



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