GAS FLOW, EMITTANCE, AND ION CURRENT CAPABILITIES OF POROUS TUNGSTEN
Abstract
Analysis of Cs ion current and propellant utilization capabilities of porous W, based on a simple model of a porous structure, indicates that pore sizes of 1 micron and less would be desirable. bGas flow measurements indicated that some difficulty might be experienced in operating smaller particle size porous W structures at the required surface temperature for high current density because of the possible sintering of the W. Experimental gas flow measurements through porous W disks made from 1-, 10-, and 20-micron powder are presented. Sintering temperatures above 1500 K affected the permeability of the 1-micron-pore material. This temperature range is a desired operating range of the Cs-W 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. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Aug 01, 1961
- Accession Number
- AD0262047
Entities
People
- Lawrence W. Kreps
- Thaine W. Reynolds
Organizations
- National Aeronautics and Space Administration