The image on the left demonstrates the instabilities that grow on the surface of a liner without a secondary magnetic field. This “bubble-and-spike” structure is caused by the magneto-Rayleigh Taylor instability, which commonly plagues z-pinch experiments. The bubble regions give up their mass to the spike regions; eventually, the bubbles break through the liner wall, and the liner’s ability to compress fuel is lost. By contrast, the image on the right shows the unique and unexpected helical instability structure that forms when the liner is premagnetized with a 7 Tesla field. Preliminary evidence suggests that this modified instability structure may work its way through the liner more slowly, enabling the liner to more effectively compress the fuel within. (Radiograph by Tom Awe.) 