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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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Germanium single crystals etching with water vapor and hydrogen sulfide in hydrogen flow system, studying concentration, pressure and temperature effects on surface reactions
Germanium microwave backward diodes optimum design and performance prediction through computer calculation for important parameters
Spectral results of p- and n-type silicon and germanium
Performance characteristics of typical silicon germanium RTG in air operation - reentry effect
Performance and weight dependence of silicon germanium RTG on fuel capsule temperature and heat flux
Electrical and thermal characteristics of silicon germanium RTG under variety load conditions in long term operation
LEED pattern and germanium surface conductivity during oxidation indicating electron states annihilation
Procedure for segmenting lead telluride and silicon germanium thermoelectric elements to obtain composite elements effective over wide temperature range
Performance of silicon-germanium thermoelement in RTG with sublimation at high operating temperatures
Long life performance predictions for lead telluride and silicon germanium radioisotope thermoelectric generators for deep space missions
Performance tests of high temperature silicon- germanium alloy thermoelectric generator for outer planet mission spacecraft
Protective xenon atmospheres in sealed silicon- germanium alloy thermoelectric generators, discussing leakage and pressure levels
Study in germanium of an optically injected electron-hole plasma, parallel and perpendicular to an applied magnetic field. The density gradient within the crystal was measured directly by an infrared-beam-absorption technique. Diffusion measurements made parallel to the magnetic field are adequately explained by the theory.
An analysis is presented that shows the desirability and feasibility of using a xenon fill in the initial stages of operation of a silicon-germanium radioisotope thermoelectric generator to be used in outer-planetary exploration. The xenon cover gas offers protection against oxidation and against material sublimation, and allows the generator to deliver required power throughout the prelaunch and launch phases. The protective mechanisms afforded by the xenon cover gas and the mechanization of a xenon supply system are also discussed.
Measurements of tunnel conductance versus bias, capacitance versus bias, and internal photoemission were made in the systems aluminum-oxide-amorphous germanium and aluminium-oxide-amorphous silicon. A function was extracted which expresses the deviation of these systems from the aluminium-oxide-aluminium system.
An enhanced residual conductivity which persists long after cessation of illumination has been observed in amorphous germanium at 77 K. The effect may be thermally quenched by heating to 120 K, returning the sample to its initial condition.
The model commonly used to describe dopant precipitation in silicon-germanium alloys is discussed. The results of an experimental program are fit to the model in order to determine the long-term behavior of the thermoelectric properties of the n-type 80 at. % Si/20 at. % Ge alloy. Thermoelectric property projections to twelve years of operating time are given.
General characteristics of the lithium-drifted germanium photodiode-Dewar-preamplifier system and particular operating instructions for the device are given. Information is included on solving operational problems.