The Z pinch is the world's largest electrical generator, housed in an entire building. It creates lightning-like tangles of startling color for a few billionths of a second as it fires. An initial burst of electricity creates a magnetic field that compresses, or "pinches," a gas of charged particles, producing x-rays.
Ross Falcon and other Sandia physicists are using x-rays generated by the Z-pinch to essentially recreate the atmospheric conditions of a white dwarf star in the laboratory.
They fire the x-rays at a thin gold target at the end of a tube filled with hydrogen, heating it up to 10,000 degrees Kelvin or so, thereby producing a plasma (ionized gas). This is a close approximation to the real thing, and subsequent analysis of the plasma's spectra has been sufficient to further refine the models being used by astronomers to calculate the mass and radius of white dwarfs.
Thus far their spectral analysis has been limited to hydrogen, but they will soon begin experimenting with helium, carbon and oxygen. And since the Z-pinch generates magnetic fields on a par with those that exist around white dwarf stars, it should be possible to figure out how those fields might affect the elemental spectra - assuming fields of such magnitude can be sufficiently controlled. Creating them is the easy part.
When all is said and done, we should know a great deal more about how white dwarf stars emit light.
Images: (top) Artist's impression of Sirius A and Sirius B. Credit: NASA, ESA and G. Bacon (STScI). (bottom) Sandia's Z-pinch in action. Source: Sandia National Lab.