Part 1: Microwave Studies of Nonionizing Shock Waves. Part 2: A Proposed Microwave Reflection Method for the Study of High Energy Shock Wave Produced High Density Plasma
Abstract
The interaction of microwaves with gaseous plasmas is used to study weak shock waves in low pressure gases. An improved technique for microwave measurement of plasma parameters is used by which the electron density and the collision frequency in a plasma are deduced from the simultaneous recording of two microwave detector signals. The validity of this method was tested in a decaying plasma created by a pulsed DC discharge in the usual way. In this method the gas is weakly pre-ionized and shock waves with a Mach number too low to ionize the gas are then propagated. Using a tube 5 mm in diameter and condenser discharges for the production of shock waves up to 200 joules with Mach number up to 5 in a pressure of 4 to 13 mmHg in Neon and Argon, the measured electron density increased across the shock discontinuities in the ratio of the gas density ratio. The electron temperature, deduced from the measured electron-ion collision frequency is, as expected, lower than the gas temperature estimated from the Mach number. In addition to the electromagnetic behavior the optical properties of the plasma are used and provide an independent source of information directly correlated with the microwave measurements. Finally, a method for measuring the higher electron densities in plasmas is proposed.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jul 01, 1962
- Accession Number
- AD0282848
Entities
People
- Lawrence S.B. Goldstein
- M. Roux
- S. Takeda
Organizations
- University of Illinois Urbana–Champaign