Collette, A | Search NASA

DOE OSTI2011

Structure of an exploding laser-produced plasma

Currents and instabilities associated with an expanding dense plasma embedded in a magnetized background plasma are investigated by direct volumetric probe measurements of the magnetic field and floating potential. A diamagnetic cavity is formed and found to collapse rapidly compared to the expected magnetic diffusion time. The three-dimensional current density within the expanding plasma includes currents along the background magnetic field, in addition to the diamagnetic current. Correlation measurements reveal that flutelike structures at the plasma surface translate with the expanding plasma across the magnetic field and extend into the current system that sustains the diamagnetic cavity, possibly contributing to its collapse.

70 PLASMA PHYSICS AND FUSION TECHNOLOGY↗

DOE OSTI2010

Structure of an Exploding Laser-Produced Plasma

We describe the first-ever volumetric, time-resolved measurements performed with a moving probe within an expanding dense plasma, embedded in a background magnetized plasma. High-resolution probe measurements of the magnetic field and floating potential in multiple 2D cut planes combined with a 1 Hz laser system reveal complex three-dimensional current systems within the expanding plasma. Static ({omega}{sub real}=0) flutelike density striations are observed at the leading edge of the plasma, which are correlated to variations in the current layer at the edge of the expanding plasma.

70 PLASMA PHYSICS AND FUSION TECHNOLOGY↗