Electron density and temperature measurement of an atmospheric pressure plasma by millimeter wave interferometer

In this paper, a 105 GHz millimeter wave interferometer system is used to measure the electron density and temperature of an atmospheric pressure helium plasma driven by submicrosecond pulses. The peak electron density and electron-neutral collision frequency reach 8x10(12) cm(-3) and 2.1x10(12) s(-1), respectively. According to the electron-helium collision cross section and the measured electron-neutral collision frequency, the electron temperature of the plasma is estimated to reach a peak value of about 8.7 eV. (C) 2008 American Institute of Physics.