Cyclotron Resonance in Slightly Ionized Gases

Abstract
The conductivity of a slightly ionized gas in a uniform magnetic field has been obtained from the solution of the Boltzmann equation for cases in which the collision frequency between electrons and neutral particles are dependent on the electron velocity. The line shapes of the cyclotron resonance absorption of energy from a high‐frequency electric field and the derivative with respect to the magnetic field of the resonance absorption have been computed. Also the relationship between the linewidth of the above curves and the collision frequency was obtained. The absorption of 9 kMc/sec microwave energy by the weakly ionized thermalized afterglows of helium, argon, oxygen, and carbon dioxide near cyclotron resonance has been measured experimentally. From these measurements the collision frequencies for thermal electrons with He, Ar, O2, and CO2 have been obtained. These collision frequencies are 2.0+0.2×108, 1.6±0.5×108, 1.7±0.2×108, and 24+2×108, respectively, for the above gases at 300°K and 1 mm Hg pressure.