On the transparency of foam in low-density foam {ital Z}-pinch experiments
- Prism Computational Sciences, Inc., Madison, Wisconsin 53703 (United States)
- Sandia National Laboratories, Albuquerque, New Mexico 87185 (United States)
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)
{ital Z}-pinch experiments have been performed on the SATURN and {ital Z} machines at Sandia National Laboratories to study physics issues related to x-ray radiation generation and inertial confinement fusion. Some of these experiments utilize a CH foam located on-axis to convert energy to radiation and act as a radiative transfer volume. A significant issue for foam {ital Z}-pinch experiments is the transparency of the heated foam as a function of time and wavelength. Foam transparency will be important in future foam {ital Z}-pinch experiments both because it influences the time-dependent radiation field seen by an inertial confinement fusion capsule embedded in the foam, and because it is an important factor in making high-resolution spectral measurements of a capsule or tracers embedded in the foam. In this article, we describe results from simulations and experiments which address the issue of foam transparency. We discuss imaging data from one {ital Z} experiment in which x-ray emission from a half-Au/half-CH disk located at the bottom of a 1-cm-tall, 14 mg/cc TPX foam is observed. Simulation results predicting CH foam optical depths as a function of plasma conditions are presented. In addition, we present results from spectral calculations which utilize 2D magnetohydrodynamic (MHD) simulation predictions for the time-dependent foam conditions. Our results indicate that the observed x-ray framing camera images are consistent with early-time (several ns prior to stagnation) foam electron temperatures of {approx_gt}30 eV, which is somewhat hotter than the foam electron temperatures predicted from the 2D MHD simulations at early times. {copyright} {ital 1999 American Institute of Physics.}
- OSTI ID:
- 295613
- Report Number(s):
- CONF-980605-; ISSN 0034-6748; TRN: 99:001799
- Journal Information:
- Review of Scientific Instruments, Vol. 70, Issue 1; Conference: 12. topical conference on high-temperature plasma diagnostics, Princeton, NJ (United States), 7-11 Jun 1998; Other Information: PBD: Jan 1999
- Country of Publication:
- United States
- Language:
- English
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