The Awsome Power of Z

Lab Notes

June / July 2007 By: Neal Singer Volume 5 Number 3

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A new type of simple electrical circuit—€”a switch, really, and a few other elementary parts—€”may lift a fusion machine such as Z at Sandia National Laboratories to the next level in the race to achieve clean energy. The circuit—€”from Siberia—€”hopefully will do this before the human race finds itself permanently camped under lowering clouds of carbon dioxide and nitrous oxide—€”the possibly unavoidable result of burning fuels derived from fossils.

Nuclear fusion in its controlled form is a ticket for clean energy. There'll be no more wars over oil if it can be mastered. But it's difficult to do. Humans have been trying for 50 years, since the explosion of a thermonuclear bomb proved that joining atoms to produce energy was not just a theory.

The jaded get a world-weary look in their eyes when nuclear fusion is mentioned. They enjoy commenting that power from the reaction is "always 30 years away." The fact that no one has stopped trying, despite the 50-year effort, is testimony to its importance.

We need energy. And not just here in the U.S. Consider the billions of Chinese and Indian brothers and sisters coming online. They want their water pumped instead of hauling it. They want to stay comfortably awake after dusk through electric lighting. They want dishwashers, microwaves and refrigerators. They want TVs, CD players and computers to compete with us. They want what we want. That means more power plants.

The beauty of fusion is that, rather than burning coal, gas or oil to produce electricity, it relies on the most widespread substance on earth: sea water. A half-bathtub full of seawater, if we could utilize it, would provide as much power as 40 train car loads of coal. It would do so without releasing gasses into the atmosphere. It would not require oil payments to countries whose interests are not ours. And it does not have certain unpleasant characteristics of nuclear fission —€”a method with which it is sometimes confused.

Fission splits large atoms like uranium. The splitting releases energy. Power plants that use this method already produce electricity. They do not produce greenhouse gasses. But the supply of uranium is finite, the fission reaction can spin out of control, and the reaction currently leaves behind long-lived radioactive waste products.

Fusion reactions run on water. They stop when interfered with because atoms are happy not to join together, or fuse. They resist like "like" magnets being pushed together. Stop pushing, they merely separate.

So what hath Sandia and a laboratory in Tomsk, Russia wrought?

Sandia's Z machine has already proven that it can fuse atoms and release energy. But to run a power plant, two things must occur: the fusion process must happen often—€”every ten seconds. And the reaction must be powerful enough that much more energy emerges than is put into it.

The Z machine has been able to fire only daily. And its power is only enough to show that fusion is possible.

But the circuit from Siberia can fire every ten seconds. It carries significant electrical current. It is modular, which means more circuits can be added like tinkertoy constructions. Computer simulations show that these circuits could fire rapidly and powerfully enough to create enough energy to run a power plant.

A Z-type machine using this circuit could be the simplest, cheapest, and fastest road to achieve nuclear fusion.

So are we there yet?

No way. Just as lightweight aircraft take years to develop and gain government certification, so would a new fusion generating plant—€”a far more difficult problem. And funding problems loom large. The Department of Energy's funds are finite, and much already has been committed to help underwrite other fusion attempts, such as a $13 billion project in France and a $3 billion effort in California.

So Z must continue to play its defense role to move forward. Data from its firings are used in supercomputer simulations. This information allows the U.S. to defer the day of returning to actual testing of nuclear weapons. More powerful firings from a facility based on the new circuits could provide more accurate data for computers. This improves Z's chances for funding.

And one day, it may be that the admittedly limited DOE coffers will open to fund a different kind of defense application with pulsed power: unlimited energy from sea water and an end to disputes over oil.

Neal Singer is a science writer at Sandia Labs who is writing a book on nuclear fusion for UNM Press. This article appeared originally in The Albuquerque Tribune.