GAS FLOW, EMITTANCE, AND ION CURRENT CAPABILITIES OF POROUS TUNGSTEN

Technical Report · Tue Aug 01 04:00:00 EDT 1961

OSTI ID:4838709

Reynolds, T W; Kreps, L W

Analysis of cesium ion current and propellant utilization capabilities of porous tungsten, based on a simple model of a porous structure, indicated that pore sizes of 1 micron and less would be desirable. Gas flow measurements indicated that some difficulty might be experienced in operating smaller particle size porous tungsten structures at the required surface temperature for high current density because of the possible sintering of the tungsten. Experimental gas flow measurements through porous tungsten disks made from 1-, 10-, and 20- micron powder are presented. Sintering temperatures above 1500 deg K affected the permeability of the 1-micron-pore material. This temperature range is a desired operating range of the cesium-tungsten system for ion rocket applications. Emissivity measurements on these same materials yielded an average spectral emittance of about 0.8 at a wavelength of 0.65 micron. Total radiation measurements gave emittance values in the range of 0.31 to 0.68. (auth)

• Research Organization: National Aeronautics and Space Administration. Lewis Research Center, Cleveland
• NSA Number: NSA-15-028038
• OSTI ID: 4838709
• Report Number(s): NASA-TN-D-871
• Country of Publication: United States
• Language: English

Related Subjects

CESIUM
EMISSION
GAS FLOW
HIGH TEMPERATURE
ION BEAMS
MEASURED VALUES
METALS, CERAMICS, AND OTHER MATERIALS
PLATES
POROSITY
POWDERS
PROPULSION
ROCKETS
SINTERING
SPECTRA
SURFACES
TESTING
THICKNESS
TUNGSTEN
USES