Measurement of ultrashort-pulse cross-polarization scattering in a tandem mirror

Cross-polarization scattering (CPS) diagnostics using ultrashort pulse micr owaves is applied to the GAMMA 10 tandem mirror for the measurement of inte rnal magnetic fluctuations. The CPS process uses the mode conversion effect of electromagnetic waves by means of magnetic fluctuations in a plasma, Th e mode contamination of antennas and multiple reflections from the vacuum v essel make the CPS measurement difficult since they easily mask the CPS sig nal. By using polarizers and performing time-of-flight measurement on the u ltrashort pulse, the spurious electromagnetic waves are eliminated and the identification of the CPS process is successful.