The Z Machine

An electrical storm lights up the surface of the Z machine, an accelerator built to simulate what happens during a nuclear explosion. The electrical discharges result from powerful electric fields that the experiment produces.

Housed at Sandia National Laboratories, the Z machine attracted a lot of attention eight years ago when its energy output more than quadrupled - raising hopes that the reactions in the Z could provide a new source of clean, abundant power. To help further progress towards this end, the machine is getting a $61.7 million upgrade, officials announced recently.

The Z uses a short burst of intense electricity - only a few 10 billionths of a second long - that forces an ionized gas to implode. The process is called a z-pinch because the pulse creates a magnetic field that squeezes particles in the vertical direction, which math books usually label as the "z-axis."

At the center of the z-pinch, in the space of a small soup can, gas particles race at each other at a million miles an hour. The collisions result in X-rays and extremely high temperatures.

Last year, when physicists placed a capsule of deuterium, or heavy hydrogen, at the focus of the z-pinch, they detected neutrons flying out from the implosion site - a signal that fusion reactions were taking place, as they do in the sun.

If researchers can learn to tame these fusion reactions, the setup can rely on a seemingly endless supply of deuterium fuel in seawater.

-- Michael Schirber

Credit: Sandia Labs