Determination of Electron-Heated Target Temperatures in Petawatt Laser Experiments Using Soft X-Ray Diagnostics*

The study of the transport of electrons, and the flow of energy into a solid target or dense plasma, is instrumental in the development of fast ignition inertial confinement fusion. Various solid targets (layered foils, cones, wires) were irradiated with the Titan Laser (4x10$^{19}$ Wcm$^{-2})$ at LLNL. Analysis has been done on soft x-ray images, spectra, and streaked images to determine the thermal electron temperatures on target back surfaces. Three independent methods (Soft X-Ray Spectrometer, 68eV XUV Imager, and 256eV XUV Imager) were used to confirm temperatures, while a fourth diagnostic (Streaked 68eV XUV Imager) provided time-resolved temperature information.