Plasma Cloaking: Air Chemistry, Broadband Absorption, and Plasma Generation
Abstract
Plasmas with electron number densities from 10(9) cm -3 to 5 x 10(11) cm -3 generated in air or a noble gas constitute tenuous plasmas. If the ambient pressure is near atmospheric, so that the gas density is of the order of 10(16) cm -3 to 10(19) cm -3, then the plasma is collisional, and the cold collisional dispersion relation predicts electromagnetic characteristics. A plasma generated by an electron beam or by photoionization produces a spatially decreasing electron density. This spatial electron density, approximated as an Epstein profile, results in low backscatter and high attenuation. Bandwidth and attenuation are quantified. An air-chemistry deionization solution is described that estimates plasma lifetime. The lifetime and electron density are sufficient to estimate the power required by a plasma absorber. Plasmas generated in air required in air require a high input power. A plasma generated in a noble gas, seeded with a readily ionized material, and confined by a membrane, requires much less power, and is technically feasible. Keywords: Atmospheric plasma, Broadband absorber, Cloaking device, Epstein profile, Noble gases, Plasma generation.
Document Details
- Document Type
- Technical Report
- Publication Date
- Feb 01, 1990
- Accession Number
- ADA222044
Entities
People
- Robert J. Vidmar
Organizations
- SRI International