Experiments on the Scaling of Ionization Balance vs. Electron and Radiation Temperature in Non-LTE Gold Plasmas
- Lawrence Livermore National Laboratory, 7000 East Avenue, L-472, Livermore, CA 94550 (United States)
Understanding and predicting the behavior of high-Z non-LTE plasmas is important for developing indirect-drive inertial confinement fusion. Extending earlier work from the Nova laser, we present results from experiments using the Omega laser to study the ionization balance of gold as a function of electron and radiation temperature. In these experiments, gold samples embedded in Be disks expand under direct laser heating to ne {approx_equal} 1021cm-3, with Te varying from 0.8 to 2.5 keV. An additional finite radiation field with effective temperature Tr up to 150 eV is provided by placing the gold Be disks inside truncated 1.2 mm diameter tungsten-coated cylindrical hohlraums with full laser entrance holes. Densities are measured by imaging of plasma expansion. Electron temperatures are diagnosed with either 2{omega} or 4{omega} Thomson scattering, and also K-shell spectroscopy of KCl tracers co-mixed with the gold. Hohlraum flux and effective radiation temperature are measured using an absolutely-calibrated multichannel filtered diode array. Spectroscopic measurements of the M-shell gold emission in the 2.9-4 keV spectral range provide ionization balance and charge state distribution information. The spectra show strong variation with Te, strong variation with the applied Tr, at Te below 1.6 keV, and relatively little variation with Tr at higher Te (upwards of 2 keV). We summarize our most recent spectral analyses and discuss emerging and outstanding issues.
- OSTI ID:
- 20630237
- Journal Information:
- AIP Conference Proceedings, Vol. 730, Issue 1; Conference: 14. APS topical conference on atomic processes in plasmas, Santa Fe, NM (United States), 19-22 Apr 2004; Other Information: DOI: 10.1063/1.1824861; (c) 2004 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 0094-243X
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
CHARGE STATES
ELECTRON TEMPERATURE
ELECTRONS
EMISSION SPECTROSCOPY
EV RANGE
GOLD
INERTIAL CONFINEMENT
ION TEMPERATURE
IONIZATION
K SHELL
KEV RANGE
LASER-RADIATION HEATING
LASERS
LTE
M SHELL
NOVA FACILITY
PHOTON EMISSION
PLASMA
PLASMA DENSITY
PLASMA DIAGNOSTICS
PLASMA EXPANSION
PLASMA PRODUCTION
POTASSIUM CHLORIDES
THOMSON SCATTERING
TUNGSTEN