Experimental investigations and analysis of parasitic RF oscillations in high-power gyrotrons - Gantenbein, G.; Dammertz, G.; Flamm, J.; Illy, S.; Kern, S.; Latsas, G.; Piosczyk, B.; Rzesnicki, T.; Samartsev, A.; Schlaich, A.; Thumm, M.; Tigelis, I (IEEE Transactions on Plasma Science, 2010)