RF Experiments on TST-2 and Plans for TST-2 and UTST

TST-2 has resumed operation after relocating to Kashiwa Campus and performing upgrades to magnetic field coil power supplies and RF heating systems. The main heating scenario used so far is high harmonic fast wave (HHFW) electron heating. Up to 400 kW of RF power 21 MHz can be injected using a pair of poloidal loop antennas separated toroidally and excited out of phase. Electron heating is indicated by a doubling of soft X-ray emission while the density and the radiated power remained unchanged. Injection of RF power at a 10 kW level to a low current ($<$ 1 kA), low density ($<$ 1$\times $10$^{17}$m$^{-3})$ plasma produced by 4 kW of ECH at 2.45 GHz caused a doubling of the plasma current. The 200 MHz transmitters transferred from the JFT-2M tokamak are being prepared for plasma current start-up experiments using waves in the lower-hybrid frequency range. Plans of RF experiments on the newly constructed UTST device will also be presented.