The Absorption and Reflection of Microwave Radiation by a Mercury-Vapour Discharge

Abstract

The power transmission and reflection coefficients of a limited volume of ionized gas (a mercury-vapour discharge) located within a waveguide have been measured at a frequency of approximately 10,000 Mc/s. by a microwave method. From these coefficients the real and imaginary components of the complex conductivity of the discharge are evaluated. The results show that the real component of the conductivity б_r is a linearly increasing function of the discharge current, whereas the rate of increase of the imaginary component б_i, which is negative, decreases with increasing discharge current. The ratio б_i/б_r, decreases with increase in current, but is of the order of unit;- due to the fact that the gas pressure is sufficiently high (_?1 atm.) to make б_r comparable with б_i. The theoretical basis of the work is presented in an appendix in which the particular case of high pressure conditions is discussed.