TIME-DEPENDENT ELECTRON-TEMPERATURE DIAGNOSTICS FOR HIGH-POWER, ALUMINUM Z-PINCH PLASMAS

Time-resolved x-ray pinhole photographs and time-integrated radially r esolved x-ray crystal-spectrometer measurements of azimuthally symmetr ic aluminum-wire implosions suggest that the densest phase of the pinc h is composed of a hot plasma core surrounded by a cooler plasma halo. The slope of the free-bound x-ray continuum, provides a time-resolved , model-independent diagnostic of the core electron temperature. A sim ultaneous measurement of the time-resolved K-shell line spectra provid es the electron temperature of the spatially averaged plasma. Together , the two diagnostics support a one-dimensional radiation-hydrodynamic model prediction of a plasma whose thermalization on axis produces st eep radial gradients in temperature, from temperatures in excess of 1 kV in the core to below 1 kV in the surrounding plasma halo. (C) 1997 American Institute of Physics.