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Results for “Opacity”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 289 records · Page 16
All sourcesNASA NTRSDOE OSTI
DOE OSTI2025

Introduction to opacity model comparison talks

I'm just giving necessary information to introduce a presentation at Z Fundamental Science Workshop Laboratory-Astrophysics Breakout session. All information are either non-technical or previously published.

Nagayama, Taisuke [Sandia National Laboratories (S↗
NASA NTRS1971

Opacity of tungsten-seeded hydrogen to 2500 K and 115 atmospheres.

Experimental investigation and measurement of the radiant heat attenuation of an aerosol which may serve as a gas core nuclear-rocket propellant. The experiment uses a tungsten-hydrogen aerosol heated to temperatures as high as 2500 K under pressures up to 115 atmospheres. The hydrogen aerosol is produced by dispersion of submicron-sized particles of tungsten in hydrogen gas. A narrow beam of broad spectrum (visible and ultraviolet) light is passed through it with the attenuation being measured as a function of wavelength. Other aerosol characteristics examined include the nature and extent of chemical reactions between the seed material and the hydrogen and the degree of dispersion of the seed material obtained before and after heating. Chemical equilibrium calculations and vapor pressure data for the refractory metals indicate that tungsten is a prime candidate for the seed material in the gas core nuclear rocket.

Williams, J. R.↗
NASA NTRS1974

Photon opacity in surfaces of magnetic neutron stars

Approximate expressions are derived for free-free, bound-free, and Thomson cross-sections of photons by gaseous matter in the presence of superstrong magnetic fields. For photons in modes whose electric field polarization is perpendicular to this magnetic field, the cross-section is reduced by approximately the squared ratio of the photon frequency to the electron cyclotron frequency if this ratio is small.

Lodenquai, J.↗