  A microwave discharge of atmospheric pressure, maintained by focused CW
radiation of a 24-GHz gyrotron in an argon flow in an external air atmosphere,
was investigated. The electron temperature was determined by the
current-voltage curve of a dual Langmuir probe placed in a plasma torch. The
electron temperature was also estimated from plasma emission spectra within the
framework of a coronal plasma model. The obtained values of the electron
temperature coincide within the measurement accuracy. Also, the electron
temperature is many times higher than the gas temperature. This fact allows us
to stand of a significantly non-equilibrium atmospheric pressure plasma.
