Analysis of the uncertainty in the measurement of electron densities in plasmas using the phase-resolved cutoff method

We have analysed the uncertainty of measured electron density using a phase-resolved wave cutoff probe and compared it with a previous cutoff probe. To determine the cutoff frequency (i.e. plasma frequency), we used the phase difference between two antennas of the cutoff probe and its slow time modulation instead of the transmittance used in the previous cutoff method. The phase-resolved cutoff method gives remarkable results under wide discharge conditions. The uncertainty of the phase-resolved cutoff method is much better than the previous cutoff method. (authors)