Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
10701270 | High Energy Density Physics | 2005 | 10 Pages |
Abstract
A dynamic hohlraum is created when an annular z-pinch plasma implodes onto a cylindrical 0.014 g/cc 6-mm-diameter CH2 foam. The impact launches a radiating shock that propagates toward the axis at â¼350 μm/ns. The radiation trapped by the tungsten z-pinch plasma forms a â¼200 eV hohlraum that provides X-rays for indirect drive inertial confinement fusion capsule implosion experiments. We are developing the ability to diagnose the hohlraum interior using emission and absorption spectroscopy of Si atoms added as a tracer to the central portion of the foam. Time- and space-resolved Si spectra are recorded with an elliptical crystal spectrometer viewing the cylindrical hohlraum end-on. A rectangular aperture at the end of the hohlraum restricts the field of view so that the 1D spectrometer resolution corresponds approximately to the hohlraum radial direction. This enables distinguishing between spectra from the unshocked radiation-heated foam and from the shocked foam. Typical spectral lines observed include the Si Lyα with its He-like satellites and the He-like resonance sequence including Heα, Heβ, and Heγ, along with some of their associated Li-like satellites. Work is in progress to infer the hohlraum conditions using collisional-radiative modeling that accounts for the radiation environment and includes both opacity effects and detailed Stark broadening calculations. These 6-mm-scale radiation-heated plasmas might eventually also prove suitable for testing Stark broadening line profile calculations or for opacity measurements.
Related Topics
Physical Sciences and Engineering
Physics and Astronomy
Astronomy and Astrophysics
Authors
J.E. Bailey, G.A. Chandler, G.A. Rochau, Y. Maron, S.A. Slutz, G.S. Dunham, I. Golovkin, P.W. Lake, R.W. Lemke, J.M. Lucas, J.J. MacFarlane, T.A. Mehlhorn, T.C. Moore, D.G. Schroen, E. Stambulchik, K. Youngblood,