Electrical conductivity of a seeded nitrogen plasma.

Abstract

The electrical conductivity of a nitrogen plasma seeded with potassium (in the form of powdered K2CO3) was measured experimentally under conditions similar to those present in MHD accelerators and compared with existing theory. By accounting for the nonuniform temperature profile in the flow, reasonable agreement between theory and experiment was found. The nitrogen vibrational mode was equilibrated at the gas temperature, and the degree of electron thermal nonequlibrium was found to be small with an energy loss factor of between 50 and 100 indicated for the electron-nitrogen interaction. The free potassium in the gas was determined to be 50 percent or less of the amount expected based on complete vaporization of the K2CO3 added to the gas. This was attributed to incomplete vaporization of the seed and seed condensation on the apparatus walls. (Author)