J. Phys. Colloques
Volume 49, Numéro C1, Mars 1988IAU Colloquium N° 102 on UV and X-ray Spectroscopy of Astrophysical and Laboratory Plasmas
|Page(s)||C1-375 - C1-378|
J. Phys. Colloques 49 (1988) C1-375-C1-378
DIAGNOSTIC CHARACTERIZATION OF LASER-IRRADIATED DOT TARGETSG. CHARATIS1, G.E. BUSCH1, B.K.F. YOUNG2 et R.E. STEWART2
1 KMS Fusion, Inc., 3621 South State Road, Ann Arbor, MI 48106, U.S.A.
2 University of California, Lawrence Livermore National Laboratory, Livermore, CA 94550, U.S.A.
We have conducted a series of experiments at the KMS CHROMA facility using dot spectroscopy techniques to characterize uncertainties associated with spectral line ratio models commonly applied in determining electron temperatures and densities. Temperatures determined from the slope of the H-like free-bound continuum and densities via holographic interferometry, are compared to line ratio methods. Dot targets of (typically 100 μmD Mg or Al) are irradiated with 2 to 40 x 1013 W/cm2 of 0.53 μm light. Time and spatial gradients are resolved using 4 diagnostics: a 4-frame holographic interferometer, an x-ray streak crystal spectrograph with a spatial imaging slit, a framing crystal x-ray spectrometer, and a conventional space-resolved time-integrating crystal spectrograph used for survey and calibration purposes. Preliminary results indicate the ionization distribution of these laser produced plasmas is not steady-state which plays an important role in measuring the temperature and and density. Electron temperatures derived from line-ratio techniques, assuming steady state conditions, disagree dramatically from simultaneous measurements using the slope of the H-like continuum. Electron densities using He-like triplet to singlet line ratios also differ from densities measured interferometrically.