Improvement of Measurement Accuracy of the Phase Imaging Interferometer in GAMMA 10

A 16-channel microwave interferometer with the phase imaging method has been reconstructed to obtain the radial plasma density distributions at the west plug cell in the GAMMA 10 tandem mirror. Signals measured by the interferometer have DC offsets, which cause a measurable error in the phase imaging measurement system. We propose the method to eliminate DC offsets from the signals in each channel easily on the analysis software.