Recent results on electron cyclotron current drive and MHD activity in RTP

The RTP tokamak (R = 0.72 m, a = 0.164 m, Bφ < 2.5 T, Ip = < 150 kA) is equipped with three gyrotrons (2 x 60 GHz, 180 kW, 100 ms each; 1 x 110 GHz, 500 kW, 200 ms) for electron cyclotron heating (ECH) and current drive (ECCD). The power from one of the 60 GHz gyrotrons is launched via an adjustable mirror from the high field side (HFS) in the 1X-mode. The power of both other gyrotrons is sent in perpendicularly to the toroidal magnetic field from the low field side (LFS). A comprehensive set of high-resolution multichannel plasma diagnostics is available to study the detailed behaviour of various plasma phenomena. First, recent diagnostic innovations are briefly discussed. Then, new physics results are presented for ohmic and EC heated plasmas. ECCD, slide-away discharges, discharges with a hollow temperature profile and MHD phenomena, including sawteeth and disruptions, are treated. (author)