SEARCH · Search NASA
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.
Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.
Charge neutralization of an In-FEEP thruster was demonstrated with three different electron sources by zeroing the floating potential of the thruster and neutralizer system. The three cathodes used in the investigation include a mixed metal thermionic cathode, a carbon nanotube field emission cathode, and a Spindt-type Mo field emission array cathode.
Radioisotope thermoelectric generators (RTGs) running off the radioisotope Pu238 are the current standard in deep space probe power supplies. While reliable, these generators are very inefficient, operating at only approx.7% efficiency. As an alternative, more efficient radioisotope thermionic emission generators (RTIGs) are being explored. Like RTGs, current RTIGs concepts use exotic materials for the emitter, limiting applicability to space and other niche applications. The high demand for long-lasting mobile power sources would be satisfied if RTIGs could be produced inexpensively. This work focuses on exposing several common materials, such as Al, stainless steel, W, Si, and Cu, to elevated temperatures under vacuum to determine the efficiency of each material as inexpensive replacements for thermoelectric materials.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Electron emission test of uranium carbide compatibility with tungsten alloys for nuclear fuel elements
Direct current converters used in space electric power system for nuclear-electric power supply
Fabrication and testing of diodes for pore-type dispenser, coated particle, and barium strontium cathodes
Design criteria for experimental heat pipe collector radiator structure
Performance and life capabilities of standard oxide cathode, pore-dispenser, and coated particle cathodes
Cesium oxides as electronegative additives, single crystal tungsten converter, vapor-deposited tunsten emitter materials, and thermodynamic meaning of electronegativity and work function
Oxidation products of cesium studied by differential thermal analysis
Life capabilities of nickel cathode alloys with oxide cathodes and coated particle cathodes in test diode
Interdiffusion in rhenium emitters fabricated by pressure bonding tested with electron beam, discussing thermal cycling effect
Emission characteristics, work function measurements, and variable spacing data on vapor-deposited tungsten emitter, and cesium pressure effects
Investigation of single crystal rehnium and tungsten alloy for advanced thermoionic converter
Performance tests on electron tubes with pore dispenser cathodes, coated particle cathodes, standard oxide cathodes, and nickel cathode diodes