MEASUREMENT OF RF IONIZATION RATES IN HIGH-TEMPERATURE AIR,

Abstract

A series of measurements of RF ionization rates in air between 3000 and 4000 K is described. The measurements were made using both X-band and K-band slot antennas in a shock tube 12 inches in diameter. The effective RF electric field, normalized by pressure, was varied from 25 to 65 V/cm-torr, over which range the ionization rate varied by more than two orders of magnitude and was much higher than in cold air. The variation of the ionization rate with the transient chemical behavior of the air behind the front is also demonstrated. The power required to produce a given ionization rate in the hot air was found to be consistently 3 dB below that for cold air, in addition to the effects of ambipolar diffusion. It is shown that these ionization rates reduce the ameliorating effect of flow convection in preventing antenna breakdown. (Author)

Document Details

Document Type
Technical Report
Publication Date
Mar 01, 1967
Accession Number
AD0820574

Entities

People

  • John B. Chown
  • Tetsu Morita
  • William C. Taylor

Organizations

  • SRI International

Tags

DTIC Thesaurus Topics

  • Antennas
  • Convection
  • Diameters
  • Diffusion
  • Electric Fields
  • High Temperature
  • Ionization
  • K Band
  • Measurement
  • Shock Tubes
  • Slot Antennas
  • Tubes
  • X Band

Fields of Study

  • Physics

Readers

  • Microwave Engineering.
  • Plasma Physics.