SPECTROSCOPIC DIAGNOSIS OF FOAM Z-PINCH PLASMAS ON SATURN

Solid and annular silicon aerogel and agar foams were imploded on the SATURN accelerator to study plasma initiation, acceleration, and stagn ation. SATURN delivers 7 MA with a 50 ns rise time to these foam loads . We fielded several spectroscopic diagnostics to measure plasma param eters throughout the z-pinch discharge. A spatially resolved single fr ame time-gated extreme ultraviolet spectrometer measured the extent of plasma ablation off the surface of the foam. A time integrated crysta l spectrometer showed that characteristic K shell radiation of silicon in the aerogel and of sulfur and sodium impurities in the agar were a ttenuated when the foam loads were coated with a conductive layer of g old. A time-resolved pinhole camera showed that in general the quality of the pinch implosions was poor but improved with increasing efforts to improve current continuity such as prepulse and conductive coating s. (C) 1997 American Institute of Physics.